one monkey typing

$150 worth of smoke in the lab. See attached picture, note the bubbling and pitting of all the chips on both boards.

I just spent about 4 hours finishing the build on my i3, including installing a heated print bed. Since I have a heated bed now, I need a bigger power supply. I grabbed an old PC power supply out of the bin and hooked it up.
Bad idea. There is now a pervasive smell of burning electronics in the lab.

I am now out of the i3 business until I get an entirely new set of electronics. I verified that I had everything hooked up properly, and the power supply appears to be putting out 12 volts, and the first two times I powered it up it seemed fine except the X motor driver appeared to have died for some reason.

The 3rd time I powered it up, the thing just flipped out and must have been generating a ridiculous amount of voltage. In about 5 seconds after turning it on, all of the Pololu driver chips CAUGHT FIRE. The Arduino is toast as well. The RAMPS board is POSSIBLY OK since there's not much on it to go wrong but I'll order up another just in case.

RepRapDiscount, here's $145. Lesson learned, a good power supply is cheaper than replacing all the electronics. Though I DID test the supply and it seemed to be reliably putting out 12 volts.

I'm probably going to forget about PC power supplies and just buy a proper 12V/20A supply.

We needed a cover to keep people from flipping this switch at the church, and I couldn't find one to buy, so 45 minutes on OpenSCAD, load white filament, print and voila. The switch is still accessible through one side.

I got a GoPro camera a week or so ago, and today got the helmet mount for it. It's designed to use an adhesive mount, but my helmet has a center vent which would force me to mount to the side, and also I don't trust adhesives. So I made this thing, and published it on Thingiverse. It's modular so it'd be easy to put the mount plate onto almost anything you can print.

I finished printing a spare parts kit today. If history is any guide, someone will come along and want to buy one any minute now.

I finally gave up on that bad ABS - it clogged a nozzle a few days ago, I baked it again, but it clogged again today. I give up, it's in the trash and I've broken out the 5# spool of black ABS I got from UltiMachine and fed it into a freshly-cleaned nozzle.

I also discovered/remembered when I opened the UltiMachine box that I ordered three optical endstops to experiment with. I soldered one of them up, then had to redesign the endstop holder a bit to be able to hold them since they use a 19.5mm hole spacing. So henceforth my endstop holders will have both 10 and 19.5mm holes.



I also ordered an SDSL card reader for the Sanguinololu electronics. I had to go to a UK seller on eBay to get one, but shipping is actually less from the UK than from most US sellers ($3). This will allow me to disconnect my computer once I start a print, and possibly to mount a hostless control panel eventually.

..and your ABS filament as well.

Since baking my ABS filament over the weekend, my print quality has improved and I haven't had any more clogs. This is not definitive, but it's suggestive of a problem, and since it can't hurt, I figure I'll start taking some care to dry my filament.

I think what I will do is to use a really large ziplock, perhaps the ones used for vacuum storage, then large dessicant packs. Then I can put the entire spool of plastic into the bag with a dessicant. The spools are fairly large. I see on eBay that ziplock bags as large as 20 gallons are available, so I can probably find some locally as well.

A web search points me to using baked Epsom salts as a dessicant. When baked at 500*F for an hour or so, Epsom salt/magnesium sulfate become anhydrous and is very hydroscopic. Putting it into coffee filters is supposed to make a heck of a good, cheap, and reusable, dessicant pack.

Been trying to catch up on 3D printing today. I finally finished up all the prints that Tom asked me to do for his friends - switchblade combs in a variety of colors - teenage boys...

So now I'm actually printing the first batch of the 175 remaining battery holders I have to print to finish up the blinkie kits. I should be able to finish this weekend, it takes about 5 hours to print a set of 25 holders.

I got the assembly instructions for the blinkie complete and ready to print.

I sat down to make more patterns for the blinkie, and after a bunch of fruitless searching, finally resigned myself to the fact that AVR Studio must have saved the project on the C: drive, which I wiped a few days ago. Luckily I have a copy on Google Docs from a couple of weeks ago, so I just had to recreate the brightness control code, which took about 45 minutes since I'd already figured out how to do it.

I also had a bunch of software to install on the laptop post-reinstall to get AVR studio, the device programmer, the 3D printing software and some other stuff working.

I'm making changes in my recommended build for a 3D printer too. I think I've talked about them here before. The only parts that are the same as what I was using a month ago are the little bar clips, the frame corners and the Z motor holders. I'm even working on a replacement for the endstop holders and the X carriage.

I still have to create and copy a music CD to distribute to the choir tomorrow morning, for all the pieces we're going to be doing. Also the pianist is getting (another) arm surgery next week so we need music on CD for the foreseeable future so I have more CDs to burn for that. I suppose I should work on that now...

I haven't posted here much, because I've been quite busy. I've set up a new site at make-something.com and am in the process of simultaneously getting a few key component kits ready for fellow GTers to build printers, and building one of the printers and writing the instructions for building.

Last night the electronics powered up and all the motors moved. Tonight I should get the extruder together and maybe even be able to print. The instructions are nearly complete. I hope to ship everything this weekend. There are already two more people wanting parts kits, but now that I have all the parts files ready to go it's just a matter of starting the printer on a new set of parts every few hours. I plan to have at least one full parts set sitting around at any given time, if for no other reason than that I would like to have parts in case my printer breaks.

It's taken me 5 weeks to get here which is longer than I expected, but it really only takes a day or two to build a printer. I've just done a lot of research on parts and materials, and it was an "interesting" time to do this since Josef Prusa just released the "iteration 2" design, and I had to decide what to borrow from that, and that resulted in some rework on things I'd already completed but in the end I think the printers are better for it.

I'm still undecided on whether to get electronics kits sitting around for people to pick up from me too - since it's so easy for people to order their own parts from Mouser. However, what I might do is just have the boards and solder on the surface mount chip (which is a bit tricky) and get the CPU chip and program the Arduino bootloader onto it, and sell just those for $30 or so (just the board and those 3 parts are $20, and it takes 15 minutes to solder the chip on and test it, and burn the bootloader into the CPU). But at that point I might be better off selling complete kits for $75 to $90.

The other issue is the GT2 belts that we're using now - there's only one US supplier that I've found and they charge a bunch for shipping - $18 or so shipping on $30 worth of parts for one printer. But $18 for $150 of parts for 5 printers too.

I also need to get the prototype blinkie for Duckon 2012 actually laid out and etched.

I came home and found that my Y pulley had snapped. I was running that belt quite tight. Luckily it seems to have broken after finishing the current print. So I'm running an 8 tooth pulley there now since it's all I had sitting around.



Since I had to get the Y platform off to re-tention the belt for the 8 tooth pulley anyway, I took the opportunity to switch to an iteration 2 style platform, with the bushing holders glued straight to the bottom of the upper platform with no leveling provision.

It's working and it's a good thing. Much simpler, no need to level, much less moving mass, signficantly less hardware, the print surface is more tightly bound to the drive belt, so it probably will help with the overshoot and oscillation I've seen on the Y axis sometimes. And now the belt attaches to the bottom, so there's a ton of room for putting on a belt tightener clamp. And there's a mile of room under the printer now, enough for power supplies and electronics. I may try designing an electronics holder that fits under there.

I still haven't figured out exactly what to do with the heated print bed, specifically where to put the thermistor. I think I might drill a hole up through the center of the bed and use a dremel or just a sharp knife to carve a small slot for it. Right now I spaced the heating board up with a couple of fender washers on each corner but that's messy.

Also I think I'm going to recommend going slightly rectangular with the top plate and print surface. 225mm square is really pretty tight to try to get clips on the edges and still get 200mm of print surface. There's no reason it can't be quite a lot longer, I think I'm going to make my next one at least 250mm long.

I did offset it to the right a bit to allow for the asymmetrical extruder. I think I might have very close to 200mm of both X and Y travel now.

I also want to do something a little nicer than the Z axis adjustment I have now, which is a thing printed from Thingiverse. It's ok but a little klunky. Also the endstop holder for the Z axis can wobble a bit, I'm going to think about a more solid mount for that, since on that axis a fraction of a millimeter matters.

LOL face
Just because.

Yay, I found a new PLA source that has a variety of colors, good plastic (4043D), reasonable prices ($65 for 2x 2.5# spools) and reasonable shipping. Now if they'll just answer my email about how the heck I order from them - there's no obvious way to do so on their website that shows products.

I like that they have 2x 2.5# spools for the same price as most are selling 5# spools - it'll allow me to stock up on colors without having to buy 5# at a time. Though at the rate I'll probably be going through blue to print TARDISes, I should probably get 5# of that anyway.

http://thefutureis3d.com