Monday, April 26, 2010

Finally getting somewhere..

Well as you may know from reading previous posts, the MakerBot at FamiLAB decided to puke up and break it's extruder somewhat. I tried to fix it, it kept having issues driving the DC gearmotor, and it was basically nonstop unhappiness. So, I decided, with all these Mendel parts hanging around, why not incorporate some of them into the MakerBot to get it at least up and running so it can print us a Mendel?

So here I begin...

Using the official MakerBot firmware with a geared stpper extruder is just way too much work and isn't really going to cut it. So, I decided to try and get RepRap's FiveD firmware up and running on the unit. It'll be good for a couple reasons.. One, I can do a few more things than I could with MakerBot, there's faster releases and better support for mods, since it was built to run a stepper extruder and has support for thermocouples out of the box. Two, I get more face time with it to really understand how that firmware and the apps work, so that when I finally get the Mendel built I'll already be pretty experienced in how to operate it and get things going.

So, I started off on that last night, getting the FiveD firmware set up with all the right pins, compiled, and uploaded to the MakerBot. I wired up a spare stepper motor controller to the extruder stepper and the I2C pins on the motherboard. I believe the H bridges in the extruder are kind of shot, so I'm doing this to get it running for now. I'm going to be making up a little mounting plate very shortly to get the Wade's geared extruder mounted up on the MakerBot Z platform. I may just clamp it to one side for now, just to test and get things moving, but I do want to get it set up properly with a bracket.

I calibrated all the axis and they seem to be moving proportionately now. Since the machine wasn't using endstops before, I had to set them up, test them and build some endstop triggers, which I made out of beer cans that happened to be laying around at FamiLAB. They seem to be working well, but I need a better way of attaching them as electrical tape just isn't cutting it. Other than that, auto-homing works properly now, all axis move, and are accurate.

The next step for hopefully tonight will be to get the extruder mounted up and start testing it.. I'm not so sure the speed settings are correct right now, but that's part of testing. I have the 0.5mm refsynderb nozzle in there and it's pretty much ready to go, just need to screw on the MakerGear HeatCore, attach my thermocouple and test that, and we should be ready to roll. I need to figure out how to get the heated build platform operational as well...

I'll be posting all this on the MakerBot wiki, as converting a MakerBot over to a geared extruder and FiveD has been an interesting task. I've been gathering some notes on the topic, and I'll be posting some pictures as well.

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