tag:blogger.com,1999:blog-3842256550533339982024-03-13T11:48:54.016-07:00XCbot: araspitfire's journey into rapid protototyping.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-384225655053333998.post-384413175126458452010-11-23T15:33:00.000-08:002010-11-24T04:53:43.210-08:00Much Progress. (just no time to blog about it)<div dir="ltr"> <div style="color: rgb(0, 0, 0);font-family:'Calibri';font-size:12pt;"> <div><span style="font-size:85%;">It's been a while since I posted. The main problem with reprap seems to be that one can either do things or write about it...</span></div> <div><span style="font-size:85%;"><br />Except for a month away on vacation, I have been very busy doing.</span></div> <div><span style="font-size:85%;"><br />I decided to construct a Mendel out of my printed parts. This I did, using a hardware kit from <a href="http://www.mendel-parts.com/">http://www.mendel-parts.com/</a>, in about a week. </span></div> <div> <span style="font-size:85%;"><br /></span><p class="mobile-photo"><span style="font-size:85%;"><a href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnjzQFfyI/AAAAAAAAAfI/Jl4cRR1q7gw/s1600/IMG_3995-723074.jpg"><img src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnjzQFfyI/AAAAAAAAAfI/Jl4cRR1q7gw/s320/IMG_3995-723074.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919106136997666" border="0" /></a></span></p></div> <div> <span style="font-size:85%;"><a href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnjGbuIZI/AAAAAAAAAfA/pVB9RFHhpDA/s1600/IMG_3993-720793.jpg"><img src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnjGbuIZI/AAAAAAAAAfA/pVB9RFHhpDA/s320/IMG_3993-720793.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919094106202514" border="0" /></a></span></div> <div><span style="font-size:85%;">I designed a supported hot-end using a standard PTFE/Brass nozzle, and spaced the extruder so that it gave maximum clearance.</span></div> <div> <span style="font-size:85%;"><br /></span></div> <div><p class="mobile-photo"><span style="font-size:85%;"><a href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnhwlC8jI/AAAAAAAAAeo/o1emsOfZ4Fg/s1600/IMG_3962-715730.jpg"><img src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnhwlC8jI/AAAAAAAAAeo/o1emsOfZ4Fg/s320/IMG_3962-715730.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919071059866162" border="0" /></a></span></p></div> <div> <span style="font-size:85%;"><br /></span></div> <div><span style="font-size:85%;">I moved my electronics over from XCBot and got it printing in PLA. At this point I discovered that having temperatures too low is a common cause of nozzle failures...</span></div><span style="font-size:85%;"><br />Then I went on vacation for a month.<br /><br />When I got back, I set about purchasing Mendel her own electronics, and I also bought an Adrian's style hot-end from Mendelparts.com. After much deliberation, I decided on another RAMPS controller. The main reason is I wanted to have a heated bed.<br /><br />I bought a complete kit as I may want to sell Mendel on after I design my own replacement. </span><div> <p class="mobile-photo"><span style="font-size:85%;"><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnk8hcD8I/AAAAAAAAAfg/UJTNIgIXR9I/s1600/IMG_0110-727430.jpg"><img src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnk8hcD8I/AAAAAAAAAfg/UJTNIgIXR9I/s320/IMG_0110-727430.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919125805567938" border="0" /></a></span></p><p class="mobile-photo"><span style="font-size:85%;"><a href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnkb3xC5I/AAAAAAAAAfQ/BNdvzubRZqM/s1600/IMG_4014-724839.jpg"><img src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnkb3xC5I/AAAAAAAAAfQ/BNdvzubRZqM/s320/IMG_4014-724839.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919117040847762" border="0" /></a></span></p></div> <div><span style="font-size:85%;">After getting everything tidy, I started printing in ABS.</span></div> <div><span style="font-size:85%;"><br /></span><p class="mobile-photo"><span style="font-size:85%;"><a href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnlJ0QJyI/AAAAAAAAAfo/VCMIHl-4P9w/s1600/IMG_0119-728702.jpg"><img src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnlJ0QJyI/AAAAAAAAAfo/VCMIHl-4P9w/s320/IMG_0119-728702.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919129374140194" border="0" /></a></span></p><span style="font-size:85%;"><br /></span><p class="mobile-photo"><span style="font-size:85%;"><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnlTj-m4I/AAAAAAAAAfw/mvPEP2w3XQ4/s1600/IMG_0121-729637.jpg"><img src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnlTj-m4I/AAAAAAAAAfw/mvPEP2w3XQ4/s320/IMG_0121-729637.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919131990236034" border="0" /></a></span></p> </div> <div><span style="font-size:85%;">While trying to print a case to put my RAMPS electronics into, I learned a few things about designing for FDM printers. Large objects with double layer thick walls tend to have the upper wall come off the bottom of the print. Perhaps a heated chamber will allow me to design thin-walled boxes in the future.<br /></span></div><span style="font-size:85%;"><br /></span><div><span style="font-size:85%;">In any case I have had good success designing and printing various things....</span></div> <div><span style="font-size:85%;"><br /></span><p class="mobile-photo"><span style="font-size:85%;"><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnkrm1euI/AAAAAAAAAfY/-BSJ_Gy-i6w/s1600/IMG_0104-726553.jpg"><img src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnkrm1euI/AAAAAAAAAfY/-BSJ_Gy-i6w/s320/IMG_0104-726553.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919121264802530" border="0" /></a></span></p><span style="font-size:85%;"><br /></span><p class="mobile-photo"><span style="font-size:85%;"><a href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TOxniDEWO8I/AAAAAAAAAew/wZKSMs_T85s/s1600/IMG_3980-716661.jpg"><img src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TOxniDEWO8I/AAAAAAAAAew/wZKSMs_T85s/s320/IMG_3980-716661.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919076022991810" border="0" /></a></span></p></div> <div><p class="mobile-photo"><span style="font-size:85%;"><a href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnhUhL_9I/AAAAAAAAAeY/RkzX4wUiH1g/s1600/IMG_0128-711218.jpg"><img src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnhUhL_9I/AAAAAAAAAeY/RkzX4wUiH1g/s320/IMG_0128-711218.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919063527489490" border="0" /></a></span></p></div> <div> <p class="mobile-photo"><span style="font-size:85%;"><a href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TOxniw_mpcI/AAAAAAAAAe4/pfCsA8tpPA8/s1600/IMG_3984-719498.jpg"><img src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TOxniw_mpcI/AAAAAAAAAe4/pfCsA8tpPA8/s320/IMG_3984-719498.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919088351126978" border="0" /></a></span></p><p class="mobile-photo"><span style="font-size:85%;"><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnhsJ5TPI/AAAAAAAAAeg/TowIK-NB75Y/s1600/IMG_0133-713935.jpg"><img src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TOxnhsJ5TPI/AAAAAAAAAeg/TowIK-NB75Y/s320/IMG_0133-713935.jpg" alt="" id="BLOGGER_PHOTO_ID_5542919069872246002" border="0" /></a></span></p></div> <div><span style="font-size:85%;"> Here's a video of my first print on Mendel.<br /><object height="385" width="640"><param name="movie" value="http://www.youtube.com/v/vHXpS-CMEDI?fs=1&hl=en_US"><param name="allowFullScreen" value="true"><param name="allowscriptaccess" value="always"><embed src="http://www.youtube.com/v/vHXpS-CMEDI?fs=1&hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" height="385" width="640"></embed></object><br /></span></div></div></div>araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com1tag:blogger.com,1999:blog-384225655053333998.post-76964985211791414252010-09-16T03:39:00.000-07:002010-09-16T08:57:47.847-07:00Tying it all together: Easy HotEnd.As mentioned early on my journey, I found a way to make a stainless steel isolator and a resistor heater block and a nozzle, using not much more than a drill-press. At the time, I had no way of testing my isolator, but since, I've printed most of a Mendel using it and am happy. It works great.<br /><br />The original blog post is here: <a href="http://araspitfire.blogspot.com/2010/06/lathe-free-resistor-extruder-heater.html"> http://araspitfire.blogspot.com/2010/06/lathe-free-resistor-extruder-heater.html</a><br /><br />I started printing my mendel using a PTFE isolator, but was experiencing leaks, and went back to the all metal design.<br /><br />A recent image of my current iteration:<br /><a href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TJH1dB89nHI/AAAAAAAAAa8/2loidhCsdqU/s1600/Picture+2.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TJH1dB89nHI/AAAAAAAAAa8/2loidhCsdqU/s320/Picture+2.jpg" alt="" id="BLOGGER_PHOTO_ID_5517460897594711154" border="0" /></a> <a href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TJH5esfSlLI/AAAAAAAAAbE/Opo2YZeidzI/s1600/Picture+1.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TJH5esfSlLI/AAAAAAAAAbE/Opo2YZeidzI/s320/Picture+1.jpg" alt="" id="BLOGGER_PHOTO_ID_5517465324239361202" border="0" /></a><br /><br />You can see that I have a slightly longer MIG tip as nozzle, cut off with a tubing cutter so that the hole shrinks. The M6 thread on that is fully tightened (using flats files on by hand) into my aluminium resistor block. The block has 2 large holes and a shallow one for the thermistor.. one of the holes is M6 threaded right through the block.<br /><br />I have surrounded the block with PTFE plate 1mm thick, and wrapped it with kapton. Kapton tape only would likely be enough, but the layer of PTFE makes it harder to get burned. I have secured the (etched one side) PTFE to the block with permatex high temperature gasket maker. This holds the resistor in and adds more insulation. I also secure the thermistor with gasket maker, and a layer of kapton holding it in. From drilling to heat, less than an hour has passed for using this as the gasket maker doesn't mind 220 degrees C before curing.<br /><br />Inserted into the top of my aluminum block is the stainless steel threaded isolator. It is secured with a check-nut (not shown).<br /><br />It is an M6 threaded rod drilled out as per the above blog article. I used a drill press and a hand drill to re-work this bit of threaded rod.<br /><br />One special tool I had was a tapered reamer to open the bottom of the 3.2mm hole into a taper.. nophead seems to think this is important, and after playing with a standard brass nozzle, I am inclined to agree. Force to push the feed-stock through this hot-end is much less than through my bought brass one, with the same exit hole.<br /><br />You can see I also ground down part of the isolator to reduce heat path up the isolator.. this was done with a dremel with stone on it. I mounted the dremel on a hinged board so that it was able to come close to, but not touch a bit of 3mm rod mounted in a vice. I then inserted the isolator, turned on the dremel and rotated it by hand until the dremel was removing no more material... This makes for a thin spot relative to the inner hole, and eliminates the risk of grinding through.<br /><br />Threaded onto the isolator is a bit of copper plate I had around, drilled and tapped M6. This is to help transfer heat out of the isolator, into the salvaged heatsink. You can see the heatsink compound on that interface.<br /><br />The Heatsink is from an old power supply, the roughened black anodized texture on it makes it very powerful. It is also drilled and M6 tapped. Notice it is not touching the extruder chasis, more heat isolation at work.<br /><br />Mounted is my 40mm fan, (later changed for a 30mm salvaged fan mounted in an rp printed duct.<br /><br /><a href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TJH5h4NCKII/AAAAAAAAAbU/G7fOXw0OIdc/s1600/IMG_3901.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TJH5h4NCKII/AAAAAAAAAbU/G7fOXw0OIdc/s320/IMG_3901.jpg" alt="" id="BLOGGER_PHOTO_ID_5517465378923620482" border="0" /></a> <a href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TJH5gFUnVrI/AAAAAAAAAbM/nYbSzq7xRTM/s1600/IMG_3903.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TJH5gFUnVrI/AAAAAAAAAbM/nYbSzq7xRTM/s320/IMG_3903.jpg" alt="" id="BLOGGER_PHOTO_ID_5517465348085339826" border="0" /></a><br /><br />I can say that this arrangement allows virtually no heat to enter my extruder chasis. The little fan and great heatsink pulls all the heat out of my isolator before it can make it's way into the structure above.<br /><br />I have not talked about resistor size in this post as it is dependent on power supply voltage. I'm using 19.5V laptop power supplies, so I am using a 10 ohm resistor. Larger power resistors are always good, but due to the fact that we are heatsinking and temperature controlling them... maximum temperature rating is far more important. Like nophead, I'm using <span title="W22 vitreous wirewound resistor,10R 6W">vitreous wirewound resistors. <a href="http://nl.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=159-376">I get mine from RS components here.</a></span><br /><br /><br />Simply drill the resistor hole out to be slightly larger than your resistor you wish to use, wrap the resistor in aluminum foil until it is a tight fit in the hole. Secure the resistor from sliding with goop, or kapton and the job is done.<br /><br />To recap, I'm able to extrude through a .5mm copper hole, with a skeinforge feed speed of 60mm/s with this setup. It cools off and heats up with no problems, doesn't jam or leak. The most advanced and expensive tool used was a drill press. (needed for the isolator and nozzle, not so much for the resistor block).<br /><br />If one only had a hand drill and a tap, the resulting block could be mounted on an 'old school' threaded nozzle and isolator..<br /><br />The cost of the SS threaded rod as a couple of euros. The cost of the aluminum was negligeable (I used scrap), the cost of the MIG tip was less than 3 euros. I could make another one of these and be printing through it in a few hours. In fact I will for my mendel. I'll let you know about any problems I encounter mating it to a Wade's extruder on the ABS mendel carriage.<br /><br />Hope this is helpful to someone.<br /><br />I'll finish with images of my recent successes.<br /><br /><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TJIAVmDThhI/AAAAAAAAAbs/MfR1enl8d3U/s1600/IMG_3934.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TJIAVmDThhI/AAAAAAAAAbs/MfR1enl8d3U/s320/IMG_3934.jpg" alt="" id="BLOGGER_PHOTO_ID_5517472864473941522" border="0" /></a><br /><br /><a href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TJIASPoQbMI/AAAAAAAAAbk/VSm65NWVG9s/s1600/IMG_3940.jpg"><img style="cursor: pointer; width: 266px; height: 320px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TJIASPoQbMI/AAAAAAAAAbk/VSm65NWVG9s/s320/IMG_3940.jpg" alt="" id="BLOGGER_PHOTO_ID_5517472806915304642" border="0" /></a>araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com1tag:blogger.com,1999:blog-384225655053333998.post-53386067090070585452010-09-09T14:45:00.000-07:002010-09-16T09:07:19.134-07:00MIG tips revisited.I came up with an idea to turn a 0.8mm hole in a .6 MIG electrode into a smaller hole...<br /><br />take one of these:<br /><br /><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TIlV77GnmwI/AAAAAAAAAaY/9McC2Skb4Fc/s1600/unnamed.jpg"><img style="cursor: pointer; width: 220px; height: 220px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TIlV77GnmwI/AAAAAAAAAaY/9McC2Skb4Fc/s320/unnamed.jpg" alt="" id="BLOGGER_PHOTO_ID_5515033706657979138" border="0" /></a><br /><br />Actually I used something like this, but same principal:<br /><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TIlV8DpCrqI/AAAAAAAAAag/miJBQdAKC48/s1600/9094093_lg.jpg"><img style="cursor: pointer; width: 320px; height: 320px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TIlV8DpCrqI/AAAAAAAAAag/miJBQdAKC48/s320/9094093_lg.jpg" alt="" id="BLOGGER_PHOTO_ID_5515033708949843618" border="0" /></a><br /><br /><br /><br />Stick an M6 thread into a bit of plate to use as a handle on the tip.. and slowly work you way down till it parts.<br /><br />It ends up looking like the opposite number to this:<br /><br /><a href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TIlV8bkFz5I/AAAAAAAAAao/qu2OenoSC0Q/s1600/IMG_3908.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TIlV8bkFz5I/AAAAAAAAAao/qu2OenoSC0Q/s320/IMG_3908.jpg" alt="" id="BLOGGER_PHOTO_ID_5515033715371528082" border="0" /></a><br /><br />Last step is to drill out the length of the body to 3.5mm. laying your 'handle' on the drill press table gets you straight, but then you need to hold the tip from spinning (vice-grips). Then drill as close to the end as you dare.<br /><br />The resulting nozzle hole is pretty much the same as my 0.5mm purchased nozzle, and it looks like the reduction is .1 to .2 mm deep.<br /><br />The nozzle works very will in my new extruder with all metal isolator.<br /><br />More on that later.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com6tag:blogger.com,1999:blog-384225655053333998.post-92029734740939598062010-09-09T07:45:00.000-07:002010-09-09T07:53:09.074-07:00Radiant HeatI figured that shining a light on a matte-black surface would be more efficient than hooking up wires to my moving Y build platform.<br /><br />After getting some black construction paper to 100 deg C in less than a minute... I was worried about having too much heat with my 150W radiant heater bulb. Not the case as it turns out.<br /><br /><br />I bought some matt black high-temperature paint, cut a 2mm aluminum plate to my table size (30x24), wiped it with acetone and sprayed it matte-black.<br /><br />A couple hours later I rested it on a thermocouple, on my MDF build platform, and turned the light on it at a distance of about 30cm, normal to the surface.<br /><br />The temperature under the plate topped out in about 8 minutes, at 77 deg C. I put a piece of glass on it, and when it took another 10 minutes to get back to 80 deg, I canceled the operation, realizing that the top surface of the glass would be cooler than the plate anyways.<br /><br />Next was a layer of Kapton on top. The temperature quite quickly came up to 80 to 90 deg. C. The tape obviously absorbs IR.<br /><br />I decided to print a Wade's large gear, as I had printed one the night before on acrylic, mostly successfully, but with a bit of warp. <br /><br />I positioned the light at a 45 deg. angle, aimed into the extruder's hot-end. Temperatures were still about 90ish in front of the extruder, as measured by my IR non-contact thermometer. (I checked with the heat-light off for a sec to be sure it wasn't effected.)<br /><br /><br />I couldn't get my ABS natural to stick to it, I even wiped it with acetone... Someone on IRC was talking about 'drymount' adhesive spray, which I had laying nearby.. so gave it a try in desperation. (Amazing what you'll do when you have an audience on IRC watching a webcam feed ;-)<br /><br />Drymount worked great for getting the print to stick.<br /><br />And the 80 - 90 deg C surface temperature, plus whatever the natural ABS makes internally from the light, works for keeping the print straight.... where it's warm...<br /><br />But the backside was cooler.. by quite a bit... and showed quite bad shrinking... even worse than my whole gear was exhibiting on acrylic for some reason.. I aborted the print when I saw the back lifting. <br /><br />It's clear to me that to do this, would need 2 150 watt lights, front and back... resistive heat is starting to look pretty good to me.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com1tag:blogger.com,1999:blog-384225655053333998.post-45474864854319938402010-08-31T17:09:00.001-07:002010-08-31T17:33:02.012-07:00Progress.<span style="font-size:100%;">I never did buy the bottoming tap.. I figured that since I was only tapping PTFE, and I had aluminum threads right above... I'd just make myself a tap out of Stainless M6 threaded rod...</span> <div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2athSLL1I/AAAAAAAAAZg/gb5F_ffin-w/s1600/IMG_3811.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2athSLL1I/AAAAAAAAAZg/gb5F_ffin-w/s320/IMG_3811.jpg" alt="" id="BLOGGER_PHOTO_ID_5511731625790746450" border="0" /></a></div><div><span style="font-size:100%;"><br /></span></div><div><span style="font-size:100%;">On the printing front, things progressed quite quickly. I decided to start with Repsnapper skein, as it seemed a quick solution to learning what goes on in a CNC print. I then realised that I had no idea what controls what, even in the simplified UI of Repsnapper... I read through the documents on the wiki and started making changes, then looking at the g-code to see what changed... I soon progressed to running the extruder a few cm above the build platform, and seeing if I thought the extrusion was coming out slower than the axes movement. I then started to try to print, and after 3 or 4 bad starts, I got this.</span></div> <div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TH2auwDMeyI/AAAAAAAAAZw/ObxgzxOOrb4/s1600/IMG_3833.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TH2auwDMeyI/AAAAAAAAAZw/ObxgzxOOrb4/s320/IMG_3833.jpg" alt="" id="BLOGGER_PHOTO_ID_5511731646934317858" border="0" /></a></div><div><span style="font-size:100%;"><br /></span></div><div><span style="font-size:100%;">I found that a lot of my problem is not lowering the extruder low enough to get a good stick on the surface.</span></div> <div><span style="font-size:100%;"><br /></span></div><div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2auIlt4UI/AAAAAAAAAZo/Q3cvCDyFWM8/s1600/IMG_3824.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2auIlt4UI/AAAAAAAAAZo/Q3cvCDyFWM8/s320/IMG_3824.jpg" alt="" id="BLOGGER_PHOTO_ID_5511731636341694786" border="0" /></a></div><div><span style="font-size:100%;">I quite quickly got 'dialed in' with Repsnapper, but wanted more control, and top/bottom filled layers, so Skeinforge was the order of the day.<br /><br />By the Way, I made some notes about how I got up and running for my first print in Repsnapper on the Wiki here: <a href="http://www.reprap.org/wiki/RepSnapper_Manual:Using_RepSnapper#Initial_printer_Setup_Notes">Initial_printer_Setup_Notes</a><br /></span></div> <div><span style="font-size:100%;"><br /></span></div><div><span style="font-size:100%;">I picked through the program, and with the help of people on <a href="irc://chat.freenode.net/#reprap">IRC</a>, managed to get printing quickly enough.<br /><br /></span><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bLIL9trI/AAAAAAAAAZ4/PiZ5efPGMuw/s1600/IMG_3854.jpg"><img style="cursor: pointer; width: 320px; height: 230px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bLIL9trI/AAAAAAAAAZ4/PiZ5efPGMuw/s320/IMG_3854.jpg" alt="" id="BLOGGER_PHOTO_ID_5511732134449886898" border="0" /></a><br /><br />Considering this is just 2 days of printing, and maybe 20 test blocks, I'm pretty happy with my progress.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bLuJam6I/AAAAAAAAAaA/Z-RtZ9soqfA/s1600/IMG_3861.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bLuJam6I/AAAAAAAAAaA/Z-RtZ9soqfA/s320/IMG_3861.jpg" alt="" id="BLOGGER_PHOTO_ID_5511732144639744930" border="0" /></a><br /><span style="font-size:100%;"><br />I decided to try to print something 'real'. I've always been fascinated by the possibility to print gears in reprap, so I figured my first non-test object should be a Wade's large gear.<br /><br />As you can see it turned out usable, but a bit warped. I have realized that a heated bed is a necessity when printing with ABS.<br /></span><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bMIGjcjI/AAAAAAAAAaI/0X_8-lmG6hs/s1600/IMG_3871.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bMIGjcjI/AAAAAAAAAaI/0X_8-lmG6hs/s320/IMG_3871.jpg" alt="" id="BLOGGER_PHOTO_ID_5511732151607063090" border="0" /></a><br /></div><br />As of this afternoon, I have made 3 things. All usable parts of an extruder, or a Mendel.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bMiKz3nI/AAAAAAAAAaQ/SaqXzptGtzQ/s1600/IMG_3880.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TH2bMiKz3nI/AAAAAAAAAaQ/SaqXzptGtzQ/s320/IMG_3880.jpg" alt="" id="BLOGGER_PHOTO_ID_5511732158604238450" border="0" /></a><br /><br />I'm pretty happy with what I've managed to achieve in 3 days of printing. I can only credit all the work done by other people, writing down enough information that I could pick up enough information to make wise choices, and get 'up on the curve' quickly.<br /><br />This evening, with the help of Prusajr and Bill20r3 on <a href="irc://chat.freenode.net/#reprap">IRC</a>, I tuned my Skeinforge settings even more. I have more parts to show for my efforts, each noticeably better than the last.<br /><br />I must say that I'm a believer that open source hardware really works. If someone had told me 4 months I could design and build my own 3D printer, and have it producing acceptable, usable objects before the end of the summer... I'd have thought they were crazy.<br /><br /><br />In the next day or two, I will outline my experiments using an IR heatlamp to heat my build platform from above.<br /><br />For now I'll finish with an embed:<br /><object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" id="utv329786" name="utv_n_531477" height="386" width="480"><param name="flashvars" value="loc=%2F&autoplay=false&vid=9240072&locale=en_US"><param name="allowfullscreen" value="true"><param name="allowscriptaccess" value="always"><param name="src" value="http://www.ustream.tv/flash/video/9240072?v3=1"><embed flashvars="loc=%2F&autoplay=false&vid=9240072&locale=en_US" allowfullscreen="true" allowscriptaccess="always" id="utv329786" name="utv_n_531477" src="http://www.ustream.tv/flash/video/9240072?v3=1" type="application/x-shockwave-flash" height="386" width="480"></embed></object>araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com0tag:blogger.com,1999:blog-384225655053333998.post-23697054732127141272010-08-25T16:34:00.001-07:002010-08-25T17:40:09.227-07:00Two DesignsFinal piece of the puzzle, the extruder.<br /><br />Against all advice, I decided to roll my own here too... I don't mind failure as a way to learning, and I feel that I've read enough over the past months to have a decent chance of getting this to work.<br /><br />I decided to use salvaged nylon gears out of an old printer. They fit the old Nema 14 stepper I had (perhaps they were connected in the printer) and gave me using two stages, a reasonable gear ratio.<br /><br />Pictured below is a first draft of the design, I ended up using a full 60x60x4 mm angle, and attaching the motor mount/front bulkhead with small (4-40) csunk screws.<br /><br />Pictured also is my all metal isolation, as per <a href="http://hydraraptor.blogspot.com/2009/11/no-compromise-extruder.html">nophead's no comprimise extruder</a>.<br />I used a MIG welding tip cut short (which I believe caused me problems, more later), in the bottom of my aluminum heater block. Two resistors giving me about 15 watts, and a thermistor. The heat-sink is out of an old power supply.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWo7dW6mEI/AAAAAAAAAYw/kCF1_PL3gPk/s1600/XCBot+Extruder.jpg"><img style="cursor: pointer; width: 286px; height: 320px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWo7dW6mEI/AAAAAAAAAYw/kCF1_PL3gPk/s320/XCBot+Extruder.jpg" alt="" id="BLOGGER_PHOTO_ID_5509495458604161090" border="0" /></a><br /><br /><br />This design also came to me. I am not a fan of supporting the heater through M6 thread in PTFE, as it is soft and many people have reported stripping the threads while learning to use their printer. I also ordered a brass barrel with .5 mm hole in it in case I couldn't work out the bugs in my all metal design.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWpDYFuOgI/AAAAAAAAAZY/Q42x038IbKs/s1600/XCBotPTFEHotend.jpg"><img style="cursor: pointer; width: 225px; height: 320px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWpDYFuOgI/AAAAAAAAAZY/Q42x038IbKs/s320/XCBotPTFEHotend.jpg" alt="" id="BLOGGER_PHOTO_ID_5509495594628823554" border="0" /></a><br /><br />Here is design one hooked up temporarily for testing. The motor and gears have a LOT of torque. As I discovered, it will take a large bite (1/4 of the diameter) out of the filament when it jams without even noticing...<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/THWo7g8y24I/AAAAAAAAAY4/rILI1A6_mp0/s1600/IMG_3799.jpg"><img style="cursor: pointer; width: 240px; height: 320px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/THWo7g8y24I/AAAAAAAAAY4/rILI1A6_mp0/s320/IMG_3799.jpg" alt="" id="BLOGGER_PHOTO_ID_5509495459568343938" border="0" /></a><br /><br />A closer view of the Hot-end. I left space between the heat-sink and aluminum chasis to minimize the transfer of heat. I'm using high temp gasket sealant to glue the etched PTFE 1mm plate onto the block. I'm holding it with SS locking wire as a strap. I was still waiting for kapton tape to arrive in the post. I've stuck a bit of PTFE in there to keep the thermistor wires off the strap.<br /><br />It worked very well.. during 2 or 3 hours of testing, the top of the Stainless isolator and chasis never got above 30 degrees C. It was cold to the touch if I ran the fan... at 5V. 12V was overkill.<br /><br />My 15 watts could keep up, but it felt under-powered. It took a couple minutes to heat up without the fan, and with the fan going perhaps 3-4 minutes. I recorded the duty cycle on my digital scope, and the heater was on for 60% of the time when not extruding, gradually increasing to 85% as I increased extrusion speed.<br /><br />I intend to set up a grinder to carefully thin down the SS barrel above the resistor block, thus preventing some of the heat from escaping up to my heat-sink.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWo8M8DmyI/AAAAAAAAAZA/8xYrY6Te0gk/s1600/IMG_3796.jpg"><img style="cursor: pointer; width: 240px; height: 320px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWo8M8DmyI/AAAAAAAAAZA/8xYrY6Te0gk/s320/IMG_3796.jpg" alt="" id="BLOGGER_PHOTO_ID_5509495471376407330" border="0" /></a><br /><br />My MIG tip has a 0.8mm hole in it so I was pushing quit a bit of plastic out. I increased the speed until I found a limit, where I couldn't melt the plastic fast enough for it's speed. The extruded filament speed still felt slow at this limit.<br /><br />The heater was still only on for just over 80% of the time when this limit was reached. Stripping of the filament drive started happening regularly as I ran the un-melted feed-stock into the heater end.<br /><br />I believe I have discovered that one can have too short a melt zone.<br /><br />One thing about having easy backup options, is you perhaps don't spend as much time working on a problem as you might otherwise...<br /><br />I had set out to cut another MIG tip longer, and try to decrease the hole size to .5mm or less.<br />During my attempts to melt the end of the nozzle with my TIG welder (so I could re-drill), I oxidized the top badly and decided to give that idea up as a bad job. I will perhaps re-visit stretching the tip by rolling it, which should shrink the center hole in the narrow neck, and I can then cut it off at the narrow point.<br /><br />In the mean time I built a more conventional PTFE isolated hot-end with the purchased brass nozzle, based on the above design... as pictured below.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/THWo8qO2U3I/AAAAAAAAAZQ/WbaVRoDtyxY/s1600/IMG_3810.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/THWo8qO2U3I/AAAAAAAAAZQ/WbaVRoDtyxY/s320/IMG_3810.jpg" alt="" id="BLOGGER_PHOTO_ID_5509495479239857010" border="0" /></a><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWo8ReWvxI/AAAAAAAAAZI/6YSrpYxJAss/s1600/IMG_3808.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/THWo8ReWvxI/AAAAAAAAAZI/6YSrpYxJAss/s320/IMG_3808.jpg" alt="" id="BLOGGER_PHOTO_ID_5509495472594009874" border="0" /></a><br /><br />I also built another hot-end, this time with the same resister that nophead uses in his.. I run it at 12V and get 20 watts of heat in my little block.. it heats up very quickly indeed.<br /><br />Over the course of an hour of testing, I felt the isolator was keeping the heat away from my chassis very well. while the outside of the PTFE gets quite warm to the touch, the chassis is only slightly warm. I still have the fan mounted, and if I ran it, would keep all heat out of the top-end completely.<br /><br />I had hoped that the exposed aluminum holding the nozzle into the PTFE would help cool it down and prevent melt above the nozzle, but that is not the case.. twice I got jams after having it 200 degrees for 7 or 8 minutes... extruding slowly or not.<br /><br />When I took it apart, I saw that I had a plug above the nozzle, jamming it. Tomorrow I will do a better job of making the nozzle meet exactly with the PTFE inside. I'll be shopping for an M6 bottoming tap.<br /><br />I also spent some time figuring out how to live broadcast using ustream. I hope to use this facility to get help tuning up my system when I start Printing, hopefully tomorrow or the next day. I have recorded a little silent walk-around of my extruder on my ustream feed:<br /><a href="http://www.ustream.tv/channel/xcbot-feed">http://www.ustream.tv/channel/xcbot-feed</a><br /><br /><object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" width="480" height="386" id="utv395924" name="utv_n_413013"><param name="flashvars" value="loc=%2F&autoplay=false&vid=9131858&locale=en_US"><param name="allowfullscreen" value="true"><param name="allowscriptaccess" value="always"><param name="src" value="http://www.ustream.tv/flash/video/9131858?v3=1"><embed flashvars="loc=%2F&autoplay=false&vid=9131858&locale=en_US" width="480" height="386" allowfullscreen="true" allowscriptaccess="always" id="utv395924" name="utv_n_413013" src="http://www.ustream.tv/flash/video/9131858?v3=1" type="application/x-shockwave-flash"></embed></object>araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com0tag:blogger.com,1999:blog-384225655053333998.post-40758310645725301552010-08-12T17:27:00.001-07:002010-08-21T06:43:12.587-07:00First MovementsAfter taking 3 weeks off, I finally got XCBot operational. (as a "thing" that moves surfaces around in 3 dimensions anyways)<br /><br />Here is a photo of my temporary electronics mounting.<br />My plan is to use XCBot to either mill, or etch-resist a pcboard to mount my stepper controllers and FETs on. For now I'm running from a breadboard.<br />Everything is securely mounted, as I don't want something to pull loose and let the magic smoke out of something expensive.<br /><br />I supply a USB cable for data, 12V from a switching external disk PS for running my fan (and possibly a heater), and 20V from a large laptop PS to drive the steppers (and possibly a heater). They all attach to the electronics on the top.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRxk0IkvI/AAAAAAAAAX0/18f3Yc9wsYU/s1600/IMG_3766.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRxk0IkvI/AAAAAAAAAX0/18f3Yc9wsYU/s320/IMG_3766.jpg" alt="" id="BLOGGER_PHOTO_ID_5504684925435548402" border="0" /></a><br /><br />Here is a close-up showing my 20V power switch. It is there so that I can kill drive to the motors when things go wrong. I've also included a fuse in case a short should occure.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRymza5II/AAAAAAAAAYM/Vp6u9-VXz4g/s1600/IMG_3785.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRymza5II/AAAAAAAAAYM/Vp6u9-VXz4g/s320/IMG_3785.jpg" alt="" id="BLOGGER_PHOTO_ID_5504684943149294722" border="0" /></a><br /><br />A view from the other side, showing my cooling fan. the little stepper motor on the RH side is destined to be my extruder motor.<br />You can see how I've attached things. An acrylic plate inside the t-slot, drilled for a tywrap.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRyWP-H5I/AAAAAAAAAYE/2L78o6diybA/s1600/IMG_3782.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRyWP-H5I/AAAAAAAAAYE/2L78o6diybA/s320/IMG_3782.jpg" alt="" id="BLOGGER_PHOTO_ID_5504684938705641362" border="0" /></a><br /><br />I've run most of the wires inside empty slots. A bit of stiff, plasticized, card stock holds it in.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRxzZEbWI/AAAAAAAAAX8/8YxE8safbQ4/s1600/IMG_3777.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRxzZEbWI/AAAAAAAAAX8/8YxE8safbQ4/s320/IMG_3777.jpg" alt="" id="BLOGGER_PHOTO_ID_5504684929348562274" border="0" /></a><br /><br />Other stuff, including the opto limit switches, and trigger sheet-metal, I've attached with this wonderful double-sided tape. It has great holding strength<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRy6pO9cI/AAAAAAAAAYU/LcqLdNvMJlU/s1600/IMG_3776.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TGSRy6pO9cI/AAAAAAAAAYU/LcqLdNvMJlU/s320/IMG_3776.jpg" alt="" id="BLOGGER_PHOTO_ID_5504684948475278786" border="0" /></a><br /><br />After securing everything, I re-flashed the Arduino Mega with Tonokip's firmware, and fired up repsnapper (my host software). Things went very well. I had to reverse the opto directions in the configuration file, and also the motor directions for Y and Z axes.<br /><br />I'm still exploring the limits to my axes speed capacity, and learning how to use repsnapper, but to commemorate the moment Youtube videos of XCBot in action are <a href="http://www.youtube.com/watch?v=kXFL4GjDtb8">HERE</a>, and <a href="http://www.youtube.com/watch?v=zkp0ZkYG3bY">HERE</a>.<br /><br /><object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/kXFL4GjDtb8?fs=1&hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/kXFL4GjDtb8?fs=1&hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object><br /><br />Al...araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com1tag:blogger.com,1999:blog-384225655053333998.post-2111800194083228542010-07-17T08:49:00.000-07:002010-07-17T15:48:51.312-07:00Primary Assembly done.<div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >My yokes finally came in. As I'd done a lot of the fabrication while waiting 3 weeks for my 'next day' order, it only took me 3 and a half days to assemble it, correct some design errors, and photograph it.</span></div><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRZoiYZDI/AAAAAAAAAXU/mAOjOTnQvkY/s1600/IMG_3601.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRZoiYZDI/AAAAAAAAAXU/mAOjOTnQvkY/s320/IMG_3601.jpg" alt="" id="BLOGGER_PHOTO_ID_5494903258677273650" border="0" /></a><br /><br /><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >Some changes from the Inventor model below:</span></div> <div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" ><br /></span></div><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >I managed to make my Z axis motor work at the back with my (mendel standard) belt length. I moved the vertical assembly forward by 10mm or so to get it right. I also decided not to waste my slider channel and 44x88 extrusion by cutting it short, so I have over 32cm of vertical build volume (after I add a build platform). My X is 30cm and Y is 23.5cm</span></div> <div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" ><br /></span></div><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >I'm quite happy with this bearing design.. I can see my 12mm bearing bars flex when I load the axis, but no slop from the bearings at all. It's very slippery. If I change anything, I'll have to get stiffer linear rails first.</span></div><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRUIzQ4rI/AAAAAAAAAXM/3NM4o12PQkE/s1600/IMG_3602.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRUIzQ4rI/AAAAAAAAAXM/3NM4o12PQkE/s320/IMG_3602.jpg" alt="" id="BLOGGER_PHOTO_ID_5494903164258804402" border="0" /></a><br /><br /><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >In order not to limit my X travel, I had to come up with a narrow belt clamp. Hopefully this will hold, seems like I have quite a bit of clamp pressure. (the ends are just tucked in behind the screws below) My carriage makes it to within a couple mm of each end.</span></div><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRT8IHomI/AAAAAAAAAXE/VM28VOsqqu0/s1600/IMG_3604.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRT8IHomI/AAAAAAAAAXE/VM28VOsqqu0/s320/IMG_3604.jpg" alt="" id="BLOGGER_PHOTO_ID_5494903160856617570" border="0" /></a><br /><br /><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >This view, looking up from the bottom. shows my 1:2 timing belt ratio, making my leadscrews turn twice for each rotation of the motor. I've tested the motor with a pololu at half current (ish) and get plenty of Z power, so that's a relief.</span><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRToP9pvI/AAAAAAAAAW8/P8cE7crM9go/s1600/IMG_3608.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRToP9pvI/AAAAAAAAAW8/P8cE7crM9go/s320/IMG_3608.jpg" alt="" id="BLOGGER_PHOTO_ID_5494903155520808690" border="0" /></a><br /><br /><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >This is my Lead-screw nut clamp.. I think it will slide out if (when) I crash my z axis against the bed.. hopefully... </span></div> <div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" ><br /></span></div><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" >I ended up welding a tab on, rather than remake the part when I discovered the clamp interfered with the X carriage.</span></div><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRTP1WSWI/AAAAAAAAAW0/YdFXn1M1NNs/s1600/IMG_3605.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRTP1WSWI/AAAAAAAAAW0/YdFXn1M1NNs/s320/IMG_3605.jpg" alt="" id="BLOGGER_PHOTO_ID_5494903148966725986" border="0" /></a><br /><br /><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" ><span style="font-size:14pt;">I'm not so happy with my Z sliders. There is more movement here than I would like, and they cost a lot, with the guide-rail (30 euros), and sliders (36 euros each).. I can tighten them up some more, but then I'm worried that they'll wear out faster.</span></span></div> <div><span style="font-size:14pt;"><br /></span></div><div><span style="font-size:14pt;">I would go with my X and Y bearing arrangement, if I were to do it again, or something more conventional..</span></div><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRTHW1XYI/AAAAAAAAAWs/xsnmTPMcZWs/s1600/IMG_3618.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TEHRTHW1XYI/AAAAAAAAAWs/xsnmTPMcZWs/s320/IMG_3618.jpg" alt="" id="BLOGGER_PHOTO_ID_5494903146691255682" border="0" /></a><br /><br /><div><span style="border-collapse: separate; color: rgb(0, 0, 0); font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;font-family:Arial;font-size:14pt;" ><span style="font-size:14pt;">Other changes that happened after I started assembly... I drilled through the front of my X carriage and reversed the machine screws so I could adjust the Z slider mounts while they are on the bot... this allowed me to tighten them when everything is lined up. I've also decided not to overdo the countersunk cap screws... I get more adjust-ability by leaving them as regular socket head cap screws.</span></span></div> <div><span style="font-size:14pt;"><br /></span></div><div><span style="font-size:14pt;">Otherwise it pretty much matches the model... a good thing I think?<br /><br />More pictures <a href="http://araspitfire.smugmug.com/Other/Reprap/12334669_ii9Jk#937064269_DNHEC">here:</a><br /><br />After much deliberation, I've decided to name it XCbot.<br /></span></div>araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com1tag:blogger.com,1999:blog-384225655053333998.post-26683230371573969272010-07-10T12:23:00.000-07:002010-07-10T13:12:11.463-07:00Primary Fab DoneFor the past two weeks, I've been waiting for my RS Components order to arrive. If it weren't for all the required fab work, sitting home by the mailbox would have been a real pain.<br /><br />Most of the order is here though, and I present about 20 hours cutting and drilling.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJt8vJVII/AAAAAAAAAWk/bwFPfO4NM-w/s1600/IMG_3543.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJt8vJVII/AAAAAAAAAWk/bwFPfO4NM-w/s320/IMG_3543.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361536813487234" border="0" /></a><br /><br /><span style="font-weight: bold;">Below are some details. </span><br /><br />This is my Z axis Slider and X idler pulley<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJtgpvmVI/AAAAAAAAAWc/PraNsxzf-pg/s1600/IMG_3547.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJtgpvmVI/AAAAAAAAAWc/PraNsxzf-pg/s320/IMG_3547.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361529274636626" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJta4D8GI/AAAAAAAAAWU/I-j1ub2pFfw/s1600/IMG_3548.jpg"> </a><br /><br />Y bearing bar mounts.<br />I've counterbored the holes for the bar and idler bearing mounts, more on that later.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJta4D8GI/AAAAAAAAAWU/I-j1ub2pFfw/s1600/IMG_3548.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJta4D8GI/AAAAAAAAAWU/I-j1ub2pFfw/s320/IMG_3548.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361527724077154" border="0" /> </a><br /><br />Y axis motor mount and idler pulley.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJs2RGYVI/AAAAAAAAAWM/E1q6HB8MT90/s1600/IMG_3549.jpg"><img style="cursor: pointer; width: 320px; height: 234px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJs2RGYVI/AAAAAAAAAWM/E1q6HB8MT90/s320/IMG_3549.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361517896982866" border="0" /></a><br /><br /><br />My X and Y slider bearings. I'm using part of a Mendel bearing set.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJgx_uTpI/AAAAAAAAAWE/Bh_iBDSP0z8/s1600/IMG_3553.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJgx_uTpI/AAAAAAAAAWE/Bh_iBDSP0z8/s320/IMG_3553.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361310591930002" border="0" /></a><br /><br />Detail of how I will constrain off-axis movement. The angle mounts are notched to accept the tension bolts as a tight fit. Side play should be eliminated.<br />It occured to me to weld, but I have a rotozip bit, and using a jig, this seemed easier.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJgliUBcI/AAAAAAAAAV8/9ALn-onnXuQ/s1600/IMG_3558.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJgliUBcI/AAAAAAAAAV8/9ALn-onnXuQ/s320/IMG_3558.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361307247347138" border="0" /></a><br /><br />Detail of the Z slider bearing. It's adjustable so I can eliminate off-axis play.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJgJbN95I/AAAAAAAAAV0/QTunbujycec/s1600/IMG_3559.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJgJbN95I/AAAAAAAAAV0/QTunbujycec/s320/IMG_3559.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361299701397394" border="0" /></a><br /><br />My conterbored Z drive-screw mount.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJf2XdKhI/AAAAAAAAAVs/qOVDi8VXy4M/s1600/IMG_3560.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJf2XdKhI/AAAAAAAAAVs/qOVDi8VXy4M/s320/IMG_3560.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361294585342482" border="0" /></a><br /><br />The Flexlink yoke mounting system.. I'm just waiting on the 6 x 44mm parts to arrive from a DHL hold, to be ready to assemble.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJfqLLdeI/AAAAAAAAAVk/yx8A10KuG4A/s1600/IMG_3563.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJfqLLdeI/AAAAAAAAAVk/yx8A10KuG4A/s320/IMG_3563.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361291312625122" border="0" /></a><br /><br /><span style="font-weight: bold;">Tools that I used.</span><br /><br />Many people may not be aware that a simple chop-saw with carbide teeth makes a great job of cutting aluminium, if a cutting fluid is used.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJRa863pI/AAAAAAAAAVc/fvhNorAe-os/s1600/IMG_3564.jpg"><img style="cursor: pointer; width: 240px; height: 320px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJRa863pI/AAAAAAAAAVc/fvhNorAe-os/s320/IMG_3564.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361046708117138" border="0" /></a><br /><br />If you have multiple parts to drill, take a few minutes to make a jig... It makes a world of difference.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJRHctFcI/AAAAAAAAAVU/0Lo2javTfKc/s1600/IMG_3572.jpg"><img style="cursor: pointer; width: 240px; height: 320px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJRHctFcI/AAAAAAAAAVU/0Lo2javTfKc/s320/IMG_3572.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361041472722370" border="0" /></a><br /><br />This would have been a <a href="http://nl.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2489764">100 euro part</a> If I had ordered it from RS Components. It's the drill jig for the 18mm hole for the yoke hardware. It took me about an hour with angle-grinder, welder and drill-press.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJQsemGPI/AAAAAAAAAVM/dqcwY1Y0HLo/s1600/IMG_3578.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJQsemGPI/AAAAAAAAAVM/dqcwY1Y0HLo/s320/IMG_3578.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361034232895730" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJQVVJjRI/AAAAAAAAAVE/7-5GNfG4f0A/s1600/IMG_3581.jpg"> <img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJQVVJjRI/AAAAAAAAAVE/7-5GNfG4f0A/s320/IMG_3581.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361028019260690" border="0" /></a><br /><br />To mount and secure my bearings, I counterbored holes in all holding plates... I accomplished this by using a step-drill for the larger bearings, and this great 12mm drill bit for the 12mm bearing bars. I simply aligned the hole, clamped everything and drilled.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJQBetW8I/AAAAAAAAAU8/P9L8Yfpr_Vg/s1600/IMG_3583.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TDjJQBetW8I/AAAAAAAAAU8/P9L8Yfpr_Vg/s320/IMG_3583.jpg" alt="" id="BLOGGER_PHOTO_ID_5492361022690646978" border="0" /></a>araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com0tag:blogger.com,1999:blog-384225655053333998.post-55578292209028212012010-06-22T06:12:00.000-07:002010-06-22T14:55:42.096-07:00Lathe Free Resistor Extruder HeaterIt may be early to post this, but I'm still waiting for my hardware order to come, so I have been playing with what I can. (also, I expect that once my hardware arrives, I'll be too busy to blog much)<br />I really like<a href="http://hydraraptor.blogspot.com/2009/11/no-compromise-extruder.html"> nophead's extruder heater design</a>. I figured that It would be possible to build it without having a lathe on hand, so had a go.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC7S18TJaI/AAAAAAAAAT8/F_N7tlp-2d8/s1600/extruder_block_design_1.jpg"><img style="cursor: pointer; width: 320px; height: 178px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC7S18TJaI/AAAAAAAAAT8/F_N7tlp-2d8/s320/extruder_block_design_1.jpg" alt="" id="BLOGGER_PHOTO_ID_5485590278529295778" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TCC7S_n9FrI/AAAAAAAAAUE/I6rydGL9DYY/s1600/extruder_design_1.jpg"><img style="cursor: pointer; width: 320px; height: 268px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TCC7S_n9FrI/AAAAAAAAAUE/I6rydGL9DYY/s320/extruder_design_1.jpg" alt="" id="BLOGGER_PHOTO_ID_5485590281128318642" border="0" /></a><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCExT9gW6sI/AAAAAAAAAUU/We8uZt1-yzY/s1600/extruder_design_1a.jpg"><img style="cursor: pointer; width: 320px; height: 174px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCExT9gW6sI/AAAAAAAAAUU/We8uZt1-yzY/s320/extruder_design_1a.jpg" alt="" id="BLOGGER_PHOTO_ID_5485720040111532738" border="0" /></a><br /><br />The heater block is made from some scrap 22mm round-bar (It was a door handle in an earlier life). I cut the end square, and drilled the resistor and thermistor holes before cutting it to length. This allowed me to have a big handle for holding the bar straight in the drill press while drilling the off-center holes. I then cut it off to 10mm length and by sticking a 5mm diameter bit of round-bar in the resistor hole to hold it, I drilled the 5.5mm through hole for the nozzle and SS insulator. I tapped it to a tight tolerance (didn't open up the thread all the way), so that my fittings would be tight.<br /><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65p60r1I/AAAAAAAAAT0/o_sU-ICakgg/s1600/IMG_3516.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65p60r1I/AAAAAAAAAT0/o_sU-ICakgg/s320/IMG_3516.jpg" alt="" id="BLOGGER_PHOTO_ID_5485589845805150034" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65QLgznI/AAAAAAAAATs/SD742P0mLd4/s1600/IMG_3517.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65QLgznI/AAAAAAAAATs/SD742P0mLd4/s320/IMG_3517.jpg" alt="" id="BLOGGER_PHOTO_ID_5485589838895828594" border="0" /></a><br /><br />The nozzle is a .6mm MIG torch tip. It has M6 thread. I drilled it out to 3mm, then cut it off slightly longer than the bore. The exit hole is actually quite a bit larger than .6mm (sliding fit for mig wire), so I may close it up if I need to. I tried squeezing the end of the tip in a vise, but it didn't decrease the hole size, other than flattening it. Once I rounded the hole by squeezing around the circumference, the hole was not much smaller than original. I can melt the hole closed with my tig torch if needed and re-drill it to less than .5mm.<br /><br />To work with the tip (and the isolator), I simply drilled and tapped a hole in some scrap metal and screwed the tiny pieces in to hold them.<br /><br />The isolator was more trouble.. Having found some M6 threaded rod (BZP) at Ikea, I drilled it out to 3.3mm without effort... The hole stayed very close to center all the way though. This allowed me to believe I could easily do this without a lathe.<br /><br />Not quite so easy was the SS threaded rod I then bought to make the isolator. I found with my cheap drill-press that I was not achieving depth without coming out the side of the rod. I even tried drilling in both ends, but that didn't help. For my last try, <span style="font-size:130%;"><span style="font-weight: bold;">I kept rotating the fixture 180 degrees as I drilled</span></span>, this maintained the hole more on center. I'm confident that I could do better, and for 1.5 euros for 1m of the threaded rod, it would be cheap to keep trying. Even though the top hole is slightly off center, I think this one will work fine. I tapered the bottom hole, using a tapered reamer like nophead did.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65Huhg0I/AAAAAAAAATc/ESaJGsRaVNQ/s1600/IMG_3521.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65Huhg0I/AAAAAAAAATc/ESaJGsRaVNQ/s320/IMG_3521.jpg" alt="" id="BLOGGER_PHOTO_ID_5485589836626756418" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65cldWnI/AAAAAAAAATk/lU38u6ioc0M/s1600/IMG_3519.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC65cldWnI/AAAAAAAAATk/lU38u6ioc0M/s320/IMG_3519.jpg" alt="" id="BLOGGER_PHOTO_ID_5485589842225879666" border="0" /></a><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC6IdeVMyI/AAAAAAAAASs/6IEGOwjhdqA/s1600/IMG_3522.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC6IdeVMyI/AAAAAAAAASs/6IEGOwjhdqA/s320/IMG_3522.jpg" alt="" id="BLOGGER_PHOTO_ID_5485589000650830626" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TCC6ILmrS_I/AAAAAAAAASk/Wdxk8950VzU/s1600/IMG_3523.jpg"> <img style="cursor: pointer; width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TCC6ILmrS_I/AAAAAAAAASk/Wdxk8950VzU/s320/IMG_3523.jpg" alt="" id="BLOGGER_PHOTO_ID_5485588995853994994" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TCC6IdeVMyI/AAAAAAAAASs/6IEGOwjhdqA/s1600/IMG_3522.jpg"> </a><br /><br />I pressure tested the assembled unit, and got no bubbles from the two threaded joints at 100PSI, do am hopeful that this won't leak (.... cold... not sure what will happen when it gets hot). The Copper nozzle deforms against the SS rod end forming a seal I think.<br />For the top, I intend to M6 thread some 10mm copper plate I have to increase the heat removal from the upper part of the isolator. I may dremel some material from the isolator just above where it enters the heater block if needed. I'll put a layer of PTFE between the block and the copper heat channel. I have a nicely sized aluminum heatsink from an old PS that I intend to use forced air cooling on with a 40mm fan. Silver grease between all the necessary bits should keep the heat moving where it's supposed to.<br />Because the block is circular, I should have no trouble drilling a bit of PTFE rod to fit around it as an insulator, I just need a 22mm drill..... I may try gooping it up with the high-temp gasket maker that I'll use to insert the thermistor and resistor.<br /><br />So, in short it is possible to make a resistor block extruder heater, with SS isolator and mig nozzle with only a drill press and some hand-tools. I think it's much easier to drill SS than to run a die along it, so starting with threaded rod seems logical if you can drill more or less true. Mig tips are cheap, and if I want a smaller hole, it's quite easy for me to close it up.<br /><br />The tools I used for this are not exceptional.. A cheap and nasty Chinese drill press, an M6 tap, a chop saw (though careful hack-sawing would easily work), some bits of scrap metal for holding the tiny bits, and a belt sander (optional).<br /><br />Whether this works as a heater or not, time will tell.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com2tag:blogger.com,1999:blog-384225655053333998.post-81676776580191949602010-06-16T16:30:00.000-07:002010-06-18T01:37:21.622-07:00Parts ordered, keeping busy.I finally dropped the hammer on my RS Components order this AM.<br />The damage will be almost 700 euros. Of course with RS Components, I have minimum orders on quit a few things, so take a hundred euros off the cost of actual repstrap content. I feel that I'll be getting a very flexible and adaptable bot for this price though, so hopefully no buyer's remorse. I expected that I'd be printing for under a thousand euros, and with what I've already bought, and the few little things I'll have yet to buy, I'll be getting up there...<br /><br />While waiting for the bits to arrive, I decided to build my end-stops, and more Pololu boards. Then I just had to plug it all into my Mega and have a play.<br /><br />I'm quite happy with my breadboard setup. I have all motors turning together with a bit of code I bashed up...<br /><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TBleyk4WSDI/AAAAAAAAARM/BO14pH4vCMs/s1600/IMG_3518.jpg"><img style="cursor: pointer; width: 240px; height: 320px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TBleyk4WSDI/AAAAAAAAARM/BO14pH4vCMs/s320/IMG_3518.jpg" alt="" id="BLOGGER_PHOTO_ID_5483518244286777394" border="0" /></a><br /><br />Closeup of "the jungle"...<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBleyWUE4wI/AAAAAAAAARE/GRaK_m98Vzw/s1600/IMG_3519.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBleyWUE4wI/AAAAAAAAARE/GRaK_m98Vzw/s320/IMG_3519.jpg" alt="" id="BLOGGER_PHOTO_ID_5483518240376546050" border="0" /></a><br /><br /><br />I'm thinking that if a Pololu shield doesn't come available within the timeframe, I may just go with this and mill myself my own board.. that would be cool. Not sure how much current these bread-boards will take though.. if I go Parallel on the motors, and turn up the current.. could be some burning plastic in my future... (even before I make an extruder).<br /><br />Last night I decided that I'd start with the <a href="http://www.reprap.org/wiki/Hydra-MMM_Prototype">Hydra-MMM</a> firmware/control software. Played a bit with it today, and didn't get anything moving... I suspect I need to get more sensors hooked up (I didn't have my optos in yet). It compiles fine and talks to the host, but when I try to send commands, or feed it a g-code file, it just hangs. I'll fake up a thermistor tomorrow and see what happens.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com2tag:blogger.com,1999:blog-384225655053333998.post-12849425733225657412010-06-12T06:30:00.000-07:002010-06-18T01:39:29.841-07:00ElectronicsSomething I had trouble getting to grips with, was how small all the electronics are.<br /><br />Even though the webspace is full of pictures similar to the one below, it's hard to realise just how small things are until you have it in your hand.<br /><br />As you can see, I decided to go with the (as yet experimental) Arduino Mega, with Pololu stepper drivers. Some RepRap info on this setup can be found <a href="http://www.reprap.org/wiki/Arduino_Mega_Pololu_Shield">here </a>and <a href="http://www.reprap.org/wiki/Pololu_Electronics">here</a>.<br /><br />I ordered the Arduinos and stepper motors from <a href="http://reprapsource.com/en/shop">reprapsource</a> in two batches.. both orders came without delay or hassle.<br /><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBOQKwOM0TI/AAAAAAAAAQI/6HExDT9_2t8/s1600/IMG_3495.jpg"><img style="cursor: pointer; width: 320px; height: 240px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBOQKwOM0TI/AAAAAAAAAQI/6HExDT9_2t8/s320/IMG_3495.jpg" alt="" id="BLOGGER_PHOTO_ID_5481883685857579314" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBOXM_Sw-8I/AAAAAAAAAQg/b65S8RObl74/s1600/IMG_3497.jpg"><img style="cursor: pointer; width: 260px; height: 238px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBOXM_Sw-8I/AAAAAAAAAQg/b65S8RObl74/s320/IMG_3497.jpg" alt="" id="BLOGGER_PHOTO_ID_5481891420844391362" border="0" /></a><br /><br />I put one of my Nema 23 motors in the picture for comparison. I honestly didn't realise that the Mega would be this small either... In fact I ordered an Arduino Nano (pictured below), so that I would have a small Arduino micro around for play and a special need... Had I realised just how small everything is, I'd not have bothered...<br /><br />One of the things about the Pololu boards, is apparently they run hot.. I decided that I would make some heatsinks, as my steppers are rated for 1.5A. I am still at a loss as to how you can design a 5mm chip die that will do 2A.<br /><br />Pictured below is my heatsink design. I simply sliced a strip of copper, and bent it over a 3mm thick bit of scrap metal. Pinched the sides with some ViceGrips, and tapped a flat on the bottom with a hammer. It looks big on the Arduino, but positively giant on the Pololu.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBOQLJiwEGI/AAAAAAAAAQQ/vffMcv_OttQ/s1600/copperheatsink.jpg"><img style="cursor: pointer; width: 344px; height: 258px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBOQLJiwEGI/AAAAAAAAAQQ/vffMcv_OttQ/s320/copperheatsink.jpg" alt="" id="BLOGGER_PHOTO_ID_5481883692654661730" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TBOYKIv6STI/AAAAAAAAAQo/QSUjiFvaTzI/s1600/IMG_3496.jpg"><img style="cursor: pointer; width: 282px; height: 258px;" src="http://4.bp.blogspot.com/_Mo1c6Vr1ls8/TBOYKIv6STI/AAAAAAAAAQo/QSUjiFvaTzI/s320/IMG_3496.jpg" alt="" id="BLOGGER_PHOTO_ID_5481892471354575154" border="0" /></a><br /><br />Not realizing that I could get the Pololu driver boards here in Europe (though I notice no one seems to be in stock), I ordered them directly from <a href="http://www.pololu.com/">Pololu</a> in The States. It took 13 days for the order to get to my door in The Netherlands, and I got dinged an extra 37 euros in customs/handling fees. (The order had other stuff in it, totaling $137 US.)<br /><br />I also bought a Mega Shield from reprapsource to mount everything on as per <a href="http://www.reprap.org/wiki/Arduino_Mega_Pololu_Shield">johnnyr</a>, but will buy a custom designed one if it becomes available before I'm ready to start mounting everything.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com0tag:blogger.com,1999:blog-384225655053333998.post-11444108897385372992010-06-10T14:41:00.001-07:002010-06-18T01:54:22.609-07:00A startAfter a month and a half of reading, thinking, reading and designing, I'm ready to start on this journey.<br /><br />It occured to me one day, that a lot of my 'play' in electronics, and mechanical things were working me towards some sort of robot. I have been designing and building things for years, and after a long break, was thinking of starting something biggish.<br /><br />I stumbled across an engadget post about RepRap one day, which made me aware that rapid prototyped parts are not just for gently handling and looking at, but can be quite structural as well... (the RepRap's key feature is that much of the structural components are printed on other RepRaps) I looked at my pile of stuff, and decided, "I can do that"... So I started to read....<br /><br />I decided I wanted to design my own cartesian bot, based on things I've read, rather than try to follow someone elses 'recipe'.<br /><br />A month later and using all sorts of ideas from all sorts of people (if it looks like something you did, and posted about, I likely got my ideas from it), I came up with this initial design:<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBGYiWYwwYI/AAAAAAAAAPY/zybR2i1RIDo/s1600/woodstrap_version_a.jpg"><img style="cursor: pointer; width: 298px; height: 320px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBGYiWYwwYI/AAAAAAAAAPY/zybR2i1RIDo/s320/woodstrap_version_a.jpg" alt="" id="BLOGGER_PHOTO_ID_5481329937379017090" border="0" /></a><br /><br /><br /><br />The bearing design was presented to me one day by <a href="http://www.gilesbathgate.com/2010/05/first-print/">Gilles </a>on the RepRap IRC channel, and I really liked it... it was a pivotal moment for me as it caused the design, which was constantly changing around in my head to suddenly 'gell'...<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZCCMXjxI/AAAAAAAAAPg/NZYut5tozQA/s1600/woodstrap_version_a_detail.jpg"><img style="cursor: pointer; width: 320px; height: 291px;" src="http://3.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZCCMXjxI/AAAAAAAAAPg/NZYut5tozQA/s320/woodstrap_version_a_detail.jpg" alt="" id="BLOGGER_PHOTO_ID_5481330481714138898" border="0" /></a><br /><br />I have, and like to use, a tig welder to make things out of aluminum, so I altered things to make use of it, and save some space.<br /><br />T-SLOT Strap<br /><br />In the end, I didn't like the idea of using MDF to build my machine out of. I expect to move this printer between my upstairs electronics room and my outside shop. The thought of lugging a big MDF box up and down my steep Netherlands stairs didn't appeal.. I have a decent metal working shop, with a chop-saw for cutting aluminum, belt sander, the welder, and various fabrication tools, unfortunately not including a milling machine, or lathe. <br /><br />I liked the idea of using t-slot beams. They keep things looking clean, give me adjustability for lining things up as I assemble, and can be used for something else later if I want.<br /><br />I came up with this:<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZCraMtRI/AAAAAAAAAPo/_Og-SfhTPC0/s1600/TSLOTStrap1.jpg"><img style="cursor: pointer; width: 320px; height: 318px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZCraMtRI/AAAAAAAAAPo/_Og-SfhTPC0/s320/TSLOTStrap1.jpg" alt="" id="BLOGGER_PHOTO_ID_5481330492778001682" border="0" /></a><br />It is based on FlexLink t-slot from RS Components, the XC size (44mm square)... It is a bit beefy, but I figure I may be wanting to push a palm router with this, and want it as stiff as possible. Plus I like the idea of using a double-wide vertical beam for fore/aft stiffness, and the smaller size wasn't available from RS in the double width. I also may decide to make it all larger if I get more space. By starting heavy, I will be able to keep all my connection hardware and just change some extrusion (and the drive system)...<br /><br />More details:<br /><br />I decided to use the FlexLink linear bearing for my Z-axis...<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZCwZr6wI/AAAAAAAAAPw/zMSOw-I_EDk/s1600/TSLOTStrap3.jpg"><img style="cursor: pointer; width: 320px; height: 244px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZCwZr6wI/AAAAAAAAAPw/zMSOw-I_EDk/s320/TSLOTStrap3.jpg" alt="" id="BLOGGER_PHOTO_ID_5481330494118030082" border="0" /></a><br /><br /><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZDaOZU4I/AAAAAAAAAP4/oYBIlHfIYks/s1600/TSLOTStrap2.jpg"><img style="cursor: pointer; width: 320px; height: 160px;" src="http://2.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZDaOZU4I/AAAAAAAAAP4/oYBIlHfIYks/s320/TSLOTStrap2.jpg" alt="" id="BLOGGER_PHOTO_ID_5481330505344963458" border="0" /></a><br /><br /><br /><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZDguHg1I/AAAAAAAAAQA/QubJDsM5x1c/s1600/TSLOTStrap4.jpg"><img style="cursor: pointer; width: 320px; height: 234px;" src="http://1.bp.blogspot.com/_Mo1c6Vr1ls8/TBGZDguHg1I/AAAAAAAAAQA/QubJDsM5x1c/s320/TSLOTStrap4.jpg" alt="" id="BLOGGER_PHOTO_ID_5481330507088626514" border="0" /></a><br /><br /><br />Bearings are mostly as per <a href="http://www.gilesbathgate.com/2010/05/first-print/">Gilles </a>design...<br /><br />I'm using 12mm bearing bar, and over constraining the bearings for added stiffness.. I think I'll be able to keep my tolerances close enough by drilling all the holes for the mounts in a stack.... We'll see in a couple weeks... =)<br /><br />As you can see, it follows quite closely to the Mendel layout, but doesn't use RP parts.<br /><br />I feel that I can scale it up to a larger size if needed at a very reasonable cost in time and money.<br /><br />I also gave thought to replacing the belts (which are full 10mm thick and not cut down as per Mendel) with leadscrew drive for milling. I would have gone directly with leadscrews right away, but it seems that no one is doing a great job of printing with them at this point, and the added speed of belts seemed prudent. With the t-slot I can change things around relatively easily to suit.<br /><br />I'm using Nema 23 motors for strength, Pololu 1/16 stepper drivers for added precision, Arduino Mega mother board. It all seems a lot heavier duty than a Mendel, but hopefully it will give me the added strength to do 'beefier' things with it.<br /><br />I have the motors and electronics already, 350 euros worth of t-slot hardware and 2 to 3 hundred more in other bits are sitting on my RS account ready to be ordered in a couple days...<br /><br />I'll report back on how things go.araspitfirehttp://www.blogger.com/profile/03036405053962975577noreply@blogger.com1