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Re: CNC machine progress


Corwin Harris Sep 24, 2012 4:39 PM
Posted in group: Makers' Alliance
Can you link to the DOS software? I might have some hardware laying about which can run it.

On Monday, September 24, 2012 11:37:45 AM UTC-4, Sam Harmon wrote:

On Saturday, Joe O, Matt, and myself spent some time trying to get the MaxNC CNC mill working with EMC2. It was a learning experience :-) So far all we've managed to do is get the spindle to run, and it only does that when the controlling computer is powered down...

It turns out the MaxNC doesn't use a "standard" stepper motor control (i.e. send step/direction per axis using 2 pins each on the parallel port) - the motors have encoders attached (making them a little more like servos), and it uses some kind of quadrature encoding and has some microcontrollers in its onboard electronics that in turn step the stepper motors. In theory, EMC2 can support this through a function called 'stepgen', but I haven't found a decent tutorial or working configuration from someone else.

There are still a few avenues we're going to try to approach:
1: Use Mach3 on a Windows machine- It looks like the MaxNC electronics are supported by Mach3. It would probably be useful to try this (in the free version of Mach3 that limits you to 500 gcode instructions per file so we don't shell out $175 or whatever) just to figure out if the electronics do in fact work. If we can get it to run at all we could maybe see what's going on in the parallel port to figure out what needs to happen for the EMC2 configuration. Now we just need a working Windows install on a machine with a parallel port...

2: Through a MaxNC yahoo group, I found the executable for the original DOS software that shipped with the machine. This may not be terribly helpful, as I can't get it to run at all in DOSbox (seems to be missing all kinds of other files)

3: Try appealing to the internet for support: Noisebridge (the San Francisco hackerspace) has (as far as I can tell) an identical mill. they claim to have it working in EMC2, but didn't share the config files. I've asked via twitter for their config. I'll probably try some targeted e-mails to them next. There's also a guy involved with the Tesla Orchestra (our new neighbors at LH) who is an EMC2 developer. He may also be a good resource.

4: If all else fails, we can chuck the existing electronics and get a Geckodrive or some other 4-axis CNC stepper driver and roll with that. I may even order some cheap-ish one soon just to experiment with.

Sam