firmware

worked on my mendel over the last several days, and installed different firmware. using http://github.com/mccoyn/reprap-firmware-fork i believe. with some minor modifications for the pin outs im using. I am still having some issues with movement but the motors are stepping now at least for the most part :)
The thermister table appears to be off but that is easily fixed. not sure yet if there is anything else missing from that firmware branch but at least it communicates with the reprap software without locking up.

mega and pololu

well, i've gotten the pololu boards soldered in and I installed buzz's mega firmware with some modifications. but.... well, every time I try to move one of the steppers it appears to lock up the board. I can get the heaters to work but havent been able to figure what the issue is yet.

There shouldnt be any reason for the board to lock up unless there is some internal conflict.

wait, i have a idea about the endstops causing this lock up. ill write more later

laser sinstering

I have been working on starting up a local hackerspace and have a computer and recycling center that is supporting the project. while i was there the other day we were talking over a dumpster full of old toner cartridges and they were mentioning that disposing of the toner its self was a problem. Then as Im looking another thought came to me, the toner is essentially powdered plastic, so why wouldn't it work as a laser sinstered powder printer.
Then today arrives in my mailbox another instructible and in it was how to make a low power laser cutter. Im thinking mix the two idea's together and you have a laser sintered powder printer.

I will post more as the project develops.

extruder issues

well, after getting the firmware installed and getting the configuration functioning ive been working on the extruder. I keep having problems getting all of my set ups functioning. All of the bowden systems ive set up have so far failed. not sure why yet but the amount of pressure required keeps pushing the bowden cable out of the connections. Some of the problem may be with the peek insulators developing to much friction on the filiment. I have tried it with pla and abs, when i use the pla it starts puddling at the top of the insulator and the filiment begins deforming from the heat. Abs just seems to jam. Eventualy i will figure out the issue but right now i just want functionality.
I have tried using one of the last of my ptfe insulators directly coupled to my original mendel extruder. Unfortunately i havent been able to fix it into the extruder mount solidly. I tried using screws but those ripped the plastic, and ive tried epoxy but that didnt develop a effective bond.

I am still working on solutions

reprap firmware and direct to stepper

Well, after seeing some of the comments to my last post I decided to try the reprap firmware again and connect the stepper driver directly to the mb using the sda/scl pins directly. The firmware appears to have uploaded to both boards so My hopes are up right now.

Another new thought came to me last night as i was working on it. I happend to look over at one of my old extruder heater expiriments that got me thinking along another line. I had tried using a stainless insulator and was using a Nordson glue gun tip in it .016 in oriface. As i looked at it all of a sudden the thought of a water jet cutting tip flashed in my head so today i threw together a pressure washer coupler, a bolt with a 1/8" hole drilled through the center and one of these tips. I was of course hoping to get enough pressure to potentialy cut through something with it but my first tries have not been promising though i have to admit we have the pressure turned way down right now due to several people cutting themselves using just regular nozzels (i think its between 900-1200psi right now) and since they are using it for production cleaning i dont have a oportunity to turn it up and see what it might do.
I also was looking at some info online and it appears the lowest pressure a commercial waterjet cutter runs at is about 20,000psi which is way higher than I want to try rigging together right now. Im hoping that i might be able to cut thin aluminum sheeting at as little as 3000# since ive seen hydraulic lines pop holes in themselves and cut through peices of sheetmetal before.

I will keep posting any info I come up with.

extruder board firmware

well, Ive desoldered both h-bridges on one of the extruder boards and soldered in wires to D5-8
and connected those to a old v1.2 stepper board hooked up to the lin stepper.

It appears to work very well though the firmware doesnt support this configuration in any way. I tried rewriting the firmware to use the outputs as enable/step/direction but had no success with it so far. I did get it stepping by just connecting the direction signal to step but then I have no way to control direction. (note: this is with makerbot firmware)

I will keep working on it though.

oh as a aditional note, when i ordered my 624 bearings i didnt order enough so im short 1 or 2 and im waiting for more to arrive before i get too excited about running mendel 109-01's axies

lin nema 17

well, I hooked up the new nema 17 stepper i got from lin to the extruder board.....
nother blown board.....

Im having some difficulty understanding why they would blow the h-bridges like this. They are supposed to be rated at 2 amps and this stepper is not supposed to draw more than that but obviously it does. My next step is going to be two fold. Im going to desolder the h's and rewire the board to connect to a regular stepper board, then reprogram the firmware to drive the stepper that way.

The other half is to assemble the pololu boards i have into something resembling what adrian posted the other day. I already downloaded the mega code into my new mega board though i didnt try personalizing it to my hardware yet, just a test download realy.

also planning on cutting my aluminum build bed today. I have a lexan sheet in the mendel right now but that was mostly just for testing and calibration.