Inspired by Kirk and the Kobayashi Maru, when Jim was faced with the near-impossible task of winding hundreds of turns of wire through a toroid core, he cheated. 🙂
By cleanly breaking the core in half and gluing one half to a spindle chucked in an electric drill, the winding became fairly easy. Super gluing the halves together afterward produced a magnetically and physically sound toroid again.
Several folks at the space helped Jim with his experiment, holding wire, counting turns, operating the drill, and of course taking pictures. Many thanks to Ti Leggett for his efforts and skills as the photographer. There are more details in Jim’s project notes, but here’s the video:
The ShapeOko now has home and limit switches for both X and Y axes. (Z is a little different.) The linuxcnc config has been updated to handle the new switches, though a little tweaking is still needed. Here’s a picture of Y axis switches while the epoxy cured:
Our shapeoko has produced its first output under control of g-code! It’s taped up on the refrigerator at the space. 🙂
Inkscape converted a bitmap of the logo to a .svg, the gcodetools extension generated g-code, and vi did the final modifications. 🙂 The .svg needs a little cleanup, but it was more than adequate for this first test.
We now have a profile that’s calibrated to within a few percent for X, Y, and Z, though there’s still work on max speeds and accelerations. This plot was made with a ballpoint pen in a very crude holder. The bitmap-to-path converter generated inside and outside paths for the lines, so the mismatch of the actual plotted paths gives us some insight into opportunities for mechanical improvement of the shapeoko/penholder system. While the penholder is responsible for some of the tracking errors, we still have a lot to do to tighten up the shapeoko. The plate joining the Y and Z axes wobbles surprisingly. But it’s starting to work!
Update 10/2/12: Using the very convenient test facilities of the axis setup in linuxcnc’s stepconf tool, I maximized travel speed on all 3 axes. The shapeoko1 profile is getting pretty usable. Here’s a little real time clip of it plotting. This one used a Sharpie, and even though it only stayed in one spot while the Z axis raised or lowered the pen, the paper bled the ink into very noticeable dots every time it stopped.
With the leads to its steppers extended, we’ve been able to get the Shapeoko to move in x, y, and z under manual jog control. Here’s a little clip. Next steps are calibration of all 3 axes and at least temporary mounting of the controller board.