Doing the RepRap #3

I’ve successfully drilled and soldered both the Gen7 v1.2 motherboard and optostops.

Redundancy is king so I made nine optostops, two of which seem broken — they light up regardless if you apply current. People in the forums helped me troubleshoot, but having confirmed that the sensors work (i.e. infinite resistance when the optos are blocked) I can’t find anything wrong with them.

What is more worrisome is that I haven’t yet tested the motherboard for shorts and whatnot; If I can mess up a 15-solder board, surely a 400-solder one is going to explode. This might be exiting; If my apartment burns down in the process, I’m crying force majeure and buying it finished, like most people seem to.

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What is remaining is everything else. I need to get all the metal parts — nuts bolts and washers — and don’t really know where to order them here in Sweden. I’m tempted to order from McMaster-Carr only because they have such a well designed site it makes me all weepy.

Hopefully, I’ll get my hands on the printed parts along with an extruder — Wade’s geared extruder — later this week when we’re going to play around with a MakerBot at KKV Elektronen, printing the boards with components at some point; It’ll be great to finally get a look at a 3D printer in action, and get a hang of the software to run it.

Speaking of which, I have to load the bootloader onto the ATMega 644-20 PU, and hope to use an old Arduino I have laying around somewhere. Sounds simple, but this would also require me to get a power supply for the rig. (12V pushing 15Amps should do it. The machine only requires 5Amps, but the heated bed requires an additional 8Amps, so there you go.) The power supply needs to be hooked up to the board, as does the Arduino, so I need to figure out what cables to use and make those, after which I get to hook computer to Arduino and let it do it’s programming magic.

The optostops need to have flags made for them, preferably out of soda cans, so that the stops can be engaged for calibration and safety. I need a couple of 5mm wide belts to drive the extruder and bed, and I can either buy them directly or split them myself from more standard widths. Having chosen to go with Wades extruder, I need to manufacture or buy a hot-end, the part of the printer where the plastic poops out, as well as the hot-bed onto which the pooping will happen. So tonight is “ordering shit online” night. That, and crying into a bottle.

So far, this has been a crash course in electronics, and the fact that I haven’t yet been electrocuted or blown a fuse is encouraging. I can almost feel my neural pathways adapt to all these Ohms, Amps and whatnots, and it’s nice to learn something new again.