Reprap Build

Here’s a little log of my reprap build, and some pictures:


Tried to get the new hot tip from working, but ran into a new problem: I think the thermocouple A/D board has stopped communicating with the main board, because the default ‘2511’ value is the only thing getting back to repsnapper. After making sure the thermocouple was insulated, and trying out different thermocouple configurations, I figured that either the cord had gone bad since the last time I tried to print something, or the A/D board was just gone. I’m giving it a rest for a day and a reboot, and then we’ll see where to go from there.


Exercised the axes, put some filament into the extruder, actually got it extruding, tried to print the customary shot glass, ran my hot tip into the bed (thank god for tape!), tightened the hold on the PTFE block (turns out the plastic pushed it out, since I didn’t tighten it much on the first pass, exercised everything again, got the hot tip closer to the bed, tried to print again, and it seems like the block threads had melted out. I’ll have to check if that in fact has happened, but that would suck if it did. Anyways, it’s time to do homework, so I’ll have to leave the printer, probably until next weekend.


Did some cable management, finally replaced all the crappy cable connectors that came with the kit with my own pack-ratted connectors. Which still didn’t work, unless you held them in exactly the right way, because the connectors on the opto-end stops just plain sucked. I really, really recommend just tearing off the tabs and soldering directly to the stops, which is also probably way more reliable. I ended up using glue and more glue to get the connectors to stay in the magic spot, which means it’s going to be very interesting once I start moving this stuff around… At any rate, all my opto endstops work! And I tried out the heater, which gave off a tiny bit of smoke, so it looks like the heater and the thermistor are working fine. Now, it’s time to try and do a real print! But only tomorrow. When neighbors won’t be wtf over the robotic sounds coming from my room.

Also! Got the software working again with 11.10: it turns out that repsnapper 2.0 does not work with the monotronics boards. I grabbed the 1.1 version from github, and that turned out to work much like I’m used to.


I know, I don’t even know when I worked on this anymore. Just noting that I worked on cables for the optoendstops, and got the flags glued in to trigger: amazing what cardstock and Elmer’s glue can do to cardstock. Still have one more cable to go.


Threw everything back together: had to glue only one part back on! Unfortunately, the z-axis base (motor side) won’t get replaced anytime soon, especially the smooth bar tensioner. Electronics work again, though! Don’t want to be too hasty, though, because I haven’t tried extruding anything. All axes can be moved around, and temperature readings are go.

Moved across the country


Spent today trying to get the electronics working. No dice: connecting seems to kill the power/leds, and I can’t raise any sort of serial communication. Mailed the Techzone folks about it, but their latency is kind of high, so there’s a large chance I won’t fix it before I leave.

Yup, I’m leaving. In 4 days, I will be off and back to school, meaning I need to ship this guy out pretty soon, so it’s likely I won’t be doing any more work on it as of now. However, when I do open it up again I should be with all my electrical doodads, meaning that I can actually do real troubleshooting.

Until then, it’s been fun.

Done with Hardware side of things


Installed the print bed, wired up the electronics, stuck together the opto-flags with tape… and it looks like the mechanical build is done. However, I forgot totally about the software side of things, so this ain’t finished yet… But none of that seems to be working atm, so I’ll have to try tomorrow, and if it doesn’t give tomorrow, then I’ll have to start up again whenever I unbox the printer in NYC. I’ll post pictures soon.


Finally got those opto-endstop cables together (hell if I know if they work), bolted on the electronics, adjusted the z-axis, loctited all the nuts.

TODO: Install the print bed and opto-endstop flags, screw together all the electronics, make it go.


Put together the extruder (again, thank god that I have my previous attempt around, and that it had normal nuts instead of those locking ones), put together the bowden cable (and letting the extruder end glue dry a bit), put in the hot tip, and discovered that these opto-endstop cables are absolute hell to put together. I’m very much tempted to just solder these wires to the board.

TODO: put together/solder the opto-endstop cables, screw together the electronics, adjust the z-axis to level the x-axis, loctite some nuts, install the print bed.


Belted up the y-axis and z-axis stages, put in my newly-gotten opto-endstops, and discovered that the extruder’s locknut is impossible to move.

TODO: finish the extruder (nut wrangling), assemble the bowden cable and associated parts, put in the hot tip, assemble the opto-endstop cables, assemble the electronics, put in the print bed, loctite some of the y-axis nuts, adjust the print bed, and… I think that’s it. I also have less than a week to finish this, so I’m going to have to hurry this up.


Hanging out with friends, and then family reunion.


I got the captive nuts into the belt drivers, adjusted the x-axis so that the x-axis motor would fit, put in the x-axis and y-axis motors, and successfully attached the x-axis belt. The y-axis comes tomorrow.

Also, electronics test: wired up all the motors (I swear I hate screw terminals so much atm) and got them to move with repsnapper. Concerning that every button click didn’t immediately elicit a motion from the motor, but I might just have to tweak the current settings once everything gets thrown together.


Put together hot end, despite misgivings about the fact when I did calibration with boiling water and ice, the boiling water came out fine, but the ice temperature measured to about 50C (dip at room temperature). I figured it was just some sort of error, partly because I didn’t want to scrape together the resources to spot weld the damn thing.

Started putting together the extruder, and futzed around with the motor/belt drivers or whatever they’re called to get yet more captive nuts in, so the motors keep driving the belts under load.


USB A-B cable obtained! Geek cred takes a hit, though, because I overpaid for it. Installed Repsnapper, ran into problems getting the official Reprap software to work. Ah well. Tried out the thermocouple thing: it looks like it might actually work as-is (just twisted, not spot welded). Note: M105 GCode, you (might be) a savior. Iffy about taking it to Techshop to spot weld it, because I don’t know if they have enough capacitors for a bank (they probably do), and I don’t know if they’d catch on to what I’m doing and start to wave their arms around (they probably wouldn’t). I’ll do some more calibration tomorrow (boiling water and ice) and we’ll see if this thermocouple is good to go.


However, I understand the nature of my thermocouple predicament: I need to twist and spot weld a new junction. If only I hadn’t taken it to Techshop in the first place… I also think I need a A-B USB cable, which I’ll try picking up tomorrow. Also, opto-endstops should be inbound.


Got z-axis smooth bars installed (with requisite filing down of parts and shifting the z-axis parts over, which meant dealing with thread-locked nuts and re-threadlocking everything). Started work on the extruder. Installed Repsnapper, going to try and read something off the thermocouple to end this saga of finding out whether this thermocouple is, in fact, broken.


So: finished x-axis by rolling up card stock to replace the ever-infuriating x-axis spacers, installed y-axis, thread-locked the frame up after squaring it, took apart the z-axis nut retainers in the z-axis so the rod actually went through them, tightened down the x-axis, installed the x-axis, took it back out to do something (I forget exactly what), and installed the x-axis again. Also found out that my thermocouple is probably broken (this might be a deal-breaking setback, where the deal is finishing before summer ends), and I thread-locked the z-axis frame parts too early, such that the x-axis is now off-kilter.


Happy hour.


Went to Techshop. Decided to give up on the x-axis spacers: it’s just plain dumb that the walls of the spacer are thin enough that you can’t drill it out properly so it actually fits over the bar. Really, I could probably whip up something with the same durability out of this huge cache of cover stock I now have. The thermocouple seems to have checked out, but it may have broken between there and here, so I’ll have to wait and see if those wires near the hot end are actually supposed to connect.


Assembled y-axis (frog board!), not integrated with the frame yet. Holding off on assembling the hot tip, since I want to test the nichrome’s resistance as suggested in the docs, and still need to drill out the x-axis spacers. Haven’t looked at the extruder yet: if nothing else, I can rip off my previous attempt, although the extruder bodies seem like they could be sufficiently different. I might be delusional, but I think I can see a glimmer at the end of the tunnel (I mean, things are starting to make sense!).


Shamefully ended up surfing the web instead of doing things.


Bust out the old printing materials (very handy to have that duplicate set) and replaced the gimpy 180 y-axis part. Then, bust out the soldering iron, finished up the 180 y-axis parts, and got the z-axis nut retainer things melted in. Yup, with a soldering iron. If it weren’t for the x-axis spacers, I think I could get much more of the mechanical assembly done.

Also, I’ll note that 3d printing services at Techshop are very, very expensive. It’s an actual pro-printer, but it’s Shapeways level pricing: $80 for 2 parts I was missing. I forgot immediately that I wanted to print such things…


Hit up Techshop to drill out these x-axis spacers, and discovered they’re not supposed to be drilled out to m6, but to m7. Might also have fiddled around with the spacers afterwards, only to throw up my hands and decide to hit Techshop again (maybe also with my own paperboard).


Got some y-axis parts assembled, and got the trimpots on the electronics half-way tuned (need to adjust the z-axis trimpot: can’t figure out how to adjust it blind, since I can’t exactly tell when the trimpot even hits one of the rails).


Instead of going to Happy Hour, spent some time doing this. The other half of the y-axis parts went swimmingly in 1 hour, and I got myself some glue so that all the nuts will stay captive. Hopefully (will Elmer’s be good enough? We’ll find out… tomorrow!).

Started to futz around with the electronics: first plug in resulted in a very hot stepper motor. Second plug in got a motor that stayed much cooler: I’m not going to stay up for much longer, so I’ll have to do the fine adjusting tomorrow. Found a couple solder balls, but I’m thinking that’s normal.


Failed to do anything, partly due to bacon cheeseburger pizza.


Got myself a soldering iron, cleaned out 4/8 of the y-axis parts, and sunk some nuts. I think the addition of glue would really ensure that the nuts are captive, and help stick 2 loose nuts. If I have time, I’ll sink the other 4 parts tomorrow. Yeah, no Less Wrong this week, work-related stuff.


Shit, I need to let my membership at Techshop go through? And I need to take an SBU to use the soldering irons? Nevermind, going with the $15 firestarter. But only tomorrow, because the store closes at 7.

Well crap, I did jack shit with the reprap today. I did work on my 3d printer guide, though.


Widened out most of the x-axis pieces so that they actually fit on the bars, and discovered I was missing x-axis spacers. I always wondered what those were for, and now it makes sense! However, I don’t have them, and cannibalizing my old collection is… actually probably the fastest way this is going to get done. Now I need Techshop for two things: to drill out these spacers so they actually fit on the bars (these seem very prone to being too small) and heating these y-axis captive nuts into small confined spaces. I suppose I’ll have to hit up Techshop very soon. On the bright side, the rest of the x-axis fits together ZOMG.


realized I left out some plastic pieces on my x-axis carriage, put them on, realized that they were the belt clamps. D’oh! Discovered essentially every x-axis part that’s supposed to clamp onto the bars is too tight, meaning lots of disassembly, scraping, and reassembly. Bleh. Decided I need a soldering iron to deal with the y-axis captive nuts, which I think I’ll have access to with a Techshop membership. Will have to check that out soon.


Almost ready to put the x-axis together. Discovered that this captive nut stuff is going to be very difficult to deal with.


Fiddled around with x-axis stuff (360 bearings actually fit! Zomg!) and figured out how to assemble the x-axis carriage. I fear the pliers have developed a taste for blood, and once I manage to smash these 360 bearing halves together, I should be able to assemble the x-axis. I stared at the y-axis instructions, and it seems a bunch of these require some sort of hot-thingie source. I have yet to lay hands on a hot thing source that would not cause my landlord to raise his eyebrows. Well, maybe if I boil them… but then again, that would raise eyebrows.


to tighten up the x-axis stuff, with more than a few fails involved (screws tightened into the wrong place, bearings rubbing parts, tight bearings). Still haven’t started the x-carriage, and


hours loosely assembling the x-axis stuff: loosely, because I could only get a hex wrench tomorrow. This went considerably slower, due in part to even now running into parts I don’t know how to put together (took me most of the time to figure out how modifications to the x-axis carriage were supposed to go together. I’ll have to update the wiki) and trying to clear out that had some gunk in recesses. Some of the design modifications were suboptimal, and are making life considerably more difficult.


Got the basic triangular frame up in 2 hours, mostly because I’ve done it before. Easy as pie, didn’t do any squaring yet.


  • Wow, USPS? When I chose the UPS option? Negative points
  • Took almost 2 weeks to get out: 1 week until it shipped, and 1 week to reach me. Definitely not the advertised 2 day lead time.
  • Opto-endstops? Backordered? Good thing I have wait shit no electronics damn it. They’re somewhere… else. Either Washington or New York
  • PSU is nice and small laptop style charger
  • Printed parts are not green: that would have been striking, but no, I got standard white instead
  • Dunno why these rods are blackened
  • All printed parts pre-drilled yessssssssssssss (mostly), which is a big part of my decision to get a kit
  • longest bars around -7mm shorter than 295mm, shortest rods are longer by… about the same amount
  • Oh my god they have huge fender washers with m3 holes I am in love
  • Wait, m6 nuts are blackened too? wtf is this shit? (Yeah, it’s probably grease, but do we really need it? And it doesn’t feel like grease)
  • Oh god so much plastic dust everywhere (after opening the printed parts bag)