rusirius published a new build:

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Thanks TMG. I'm working on some of the electronics in my spare time now until my parts arrive for the frame. My original design was a cube build, and I based it on another design I saw on open builds, but in the parts list they gave the mini-v wheels and normal gantry plates, etc. So I ended up placing an order that the OpenBuilds team told me wouldn't work together. It was a big mess but they were nice enough to get hold the order till I could get everything straight. They really are awesome! Once I started redesigning I decided to get away from the large cube frame with 5 motor design to both cut costs and simplify. Originally I overbuilt worried about wobble, etc. But once I saw some of the other great works using very open designs (i.e. the Openbot, etc) then I realized this stuff was sturdy enough that a minimal frame would be fine. I still was a little afraid of a completely openbot style design so I kept some bracing. My original design also had a lifting table for the z axis, but doing it this way moving the Y axis to the table allowed me to minimize the amount of weight on everything but the z-axis where it won't see the kind of acceleration and movement as the other two.

 

I didn't actually, well, manually only. I used an LM317K in a constant current configuration to drive the diode. In the output to adjust feedback loop I used a pot to be able to adjust the current. To be able to rasterize an image the laser power remained constant and I instead modulated the "feed rate" of the motion. Lighter pixels got moved across faster while darker ones moved slower. The results were decent, but not as good as I know they can be with modulated power to the laser itself. And thank you!

 

Exactly, though the circuit would have to be changed for anything like this. Those two 10ohm resistors in parallel are 5ohm, even if the trim pot went down to 0 ohm 1.25/5 = 250mA, barely enough current to get a 445nm diode to lase.

 

I've added a parts list for this first phase, I changed a few dimensions during the build so I'll have to update the drawing soon.

 

Sorry it took so long to respond! Yes, it was completed, at least the first 2 phases... I've yet to actually mount the router head on it yet. To be honest, once I got the 3D printer portion working I had so much fun using it I never got back here to update this. I'll get more info up soon, as well as a bunch of pics and stuff.

But yes, the build came out great. Performance wise it's fast and very accurate. It can print at ridiculous speeds and looks much better than most commercial FDM printers I've seen in terms of quality. Though I'm constantly striving to improve it!