Reprap Generation 6 Electronics

[Jolijar]

I was wondering if it would be possible to use the Gen 6 electronics here
http://reprap.org/wiki/Generation_6_Electronics
to run the laser? I'm sure it would work for the stepper motors but I don't know how you would fire the laser... any ideas?

[BenJackson]

I'm sure you can make it work if you are willing to hack on the firmware. You will want to change the stock "FiveD" firmware that gen6 ships with because it has serious math errors and various other problems.

The plastruder heater output pin is available and connected to a PWM-able output to drive the laser. I suppose worst case you could substitute heater commands for laser commands and even use stock fw!

[Jolijar]

What do you mean serious math errors? what alternative firmwares are out there?

[BenJackson]

"Sprinter" (derived from klimentkip, caruklip, tonokip, etc) is probably the most popular. Teacup is also interesting. I use klimentkip (from before it was renamed sprinter) on a gen6 on one of my 3d printers. I am laser cutting with a heavily modified Teacup on custom hardware, though that's not really my target. I just had it handy.

[bdring]

The "electronics" are not the issue, it is the firmware. I tried running my laser with it before and wrote a blog post on it.

http://www.buildlog.net/blog/2010/09/re ... er-repzap/

The big issues at the time was acceleration. I know that Sprinter has some acceleration so that might help.

It runs G-Code, so you can make a post processor to get it to work. You just pick something you can turn on and off for the laser enable. Acceleration alone works for many shapes, but G-Code only does lines and arcs. When you have a shape like an ellipse, the CAM program will break it down to lines. Accelerating and decelerating for hundreds of lines for a single shape is a problem. Most good controllers have a constant velocity feature to smooth this out. I do not know if Sprinter deals with that. If not, it is probably not a viable option.

GRBL firmware is probably more targeted at this problem.

[BenJackson]

Just ran across this old post. Quick update: Modern "sprinter" firmware has much better acceleration handling than it used to. "Marlin" has gone farther and imported the GRBL trajectory planner. It is extremely smooth, capable of interpolating circles made of tiny line segments at full (linear) speed with no stuttering.

[mikegrundvig]

I've heard the same anecdotal,Marlin is supposed to be pretty hot all around. Not at all endorsing this as I've not used it personally but the blog-based evidence is pretty substantial.