Darkly Labs Community

MeArm project 3mm plywood

As part of a project for the local library, I selected the MeArm robotic arm, primarily because it appeared affordable and could be created via laser cut plywood.

http://www.instructables.com/id/Pocket-Sized-Robot-Arm-meArm-V04/ 

I’m not so sure about the affordable part, as the parts will be about US$75 when purchased in quantity but it’s the lowest price robotic project I found that I felt could be handled by teens for the library summer camp.

5mm/sec (300mm/min) at 100% 4W laser resulted in a few cuts not getting all the way through, but easily sliced clear with a razor knife/box cutter. Four hours and three seconds elapsed time. My first real project and it came out as good as I had hoped.

The slight variation is caused by shadows from the garage lights, as the photo was taken without a flash. The plywood was purchased inexpensively from Joanne Fabrics retail store and is uniform surface both sides.

How many passes did you do at 300mm/min? I am having my own issues with clean cuts on 3mm plywood with the 4w laser.

I’m surprised that I left out that piece of information. The project was set to 6 cuts but I’ll likely perform the same thing again next time with 7 to ensure complete fall-through. Some of the gear teeth managed to leave behind pieces when popped out and I’d like to avoid that happening.

I spent about three hours fine tuning the laser to get the absolute smallest focus I could. I used a 50x illuminated magnifier to view the test cuts, having turned the focus adjustment one “knurling-bit” at a time. I marked an index point on the knurling, then ran the tests in a descending sequence. That is to say, perhaps a quarter turn or eighth turn until the tests got wider, then narrowed it to a block of test lines and indexed from there.

With the 50x magnifier, I could see 0.01 mm difference in the laser cuts so I’m confident that I have it as tuned as it can be.