We did some interesting calibration checks on the Shapeoko 2 at the space last night. Driver and viewer software for the USB microscope are now on the Shapeoko laptop. With the ‘scope mounted to the gantry looking at the lines etched on an old-school vernier caliper body we observed average backlash (difference approaching a point from different directions) of around 0.009″. Absolute accuracy varied from 0.003″ to 0.013″. That latter worst case error is about 1/3 the diameter of the holes we drill in PCBs, and so is potentially a problem.
There was some discussion of ways to improve the mounting of the drive belts. With some evidence of belt stretch, replacing all the belts is also under consideration. More details in this post on Jim’s project notes.
Thanks to Daniil, the SO2 now has a PWM speed control! We have high hopes of adding closed-loop speed feedback to it soon. We’re finally getting close to being able to machine plastic! (That’s about impossible at the native 12K RPM of the spindle.)
Workshop 88 had a table at the Southland Mini Maker Faire in Mokena on 8/22/15. Jim’s drawbot string plotter made a “big” hit, standing 6 feet above the table and drawing poster-size images.
The drawbot, a junkbox project inspired by Bill Paulson, is driven by a couple of $3 steppers from American Science and Surplus, some cheap H bridges and an Arduino clone. Software is free from Makelangelo.com. It does the heavy lifting math to convert from X-Y coordinates to the “inches of string” coordinates the polar geometry imposes on its steppers. In addition to accepting normal X-Y gcode, it can take a jpeg image and use the traveling salesman algorithm to generate a single path reflecting the darkness of different areas in the image as it’s doing in the picture above. Such a path is ideal for a plotter that doesn’t have pen lift capability. Yet.
The Workshop 88 Shapeoko 2 is coming along nicely. It recently cut this 18″ foam sign, taking advantage of the SO2’s “frontless” design that allows working on arbitrarily long pieces, even though its active work area is only about 10″x10″. Some details are here.
The Z axis auto touch-off switch, inspired by the Carvey “Smart Clamp” is now working as well. There’s a little clip of it here.
While it’s machined handles for some of its clamp bolt and even machined the scales for a knife handle replacement, its most ambitious project to date is full 3D machining of the body of a pinewood derby car. That’s still work in progress. Stay tuned!
We’ve been getting more and more requests for 3D printer demos lately. Inspired by not wanting to disappoint kids who didn’t even have their first iPad back in the days when it was magic to be able to 3D print anything – like when our Makerbot Cupcake was hot stuff – Jim has been trying to get the old printer working again. This W88 logo is one of the latest results. Not bad for an old 1-color printer! (Thanks to Bill for the color change tips.)
Its output is no match for current “appliance” 3D printers, but it’s still fine to show the basics in a nice noisy demo. Details of Jim’s adventures with the printer are captured here.
Mark Edmonson recently donated a big box of pretty high quality used battery powered laser levels to us. They’re in various states, from apparently completely functional to rather dead.
Each one contains 5 diode lasers, as well as some other parts. There are fairly complete teardown notes and pictures here.
Here are the parts I salvaged from one.
Two members of Workshop 88 went to hear Massimo Banzi’s talk on Arduino, open source hardware and more. The talk was part of Ge Garage’s Idea Week. He gave some great stories of the philosophy, joys and problems of putting the Arduino out as open source hardware.
Among many other insights, he described how the fashion industry – with no intellectual property protection – made a lot more money than the entertainment and music industries with all their DRM efforts. He told of the value of the many iterations of Arduino and how a primary metric of its success was the time between a new user opening the box and getting a useful result. We learned it was named for a bar where they held many design meetings. It was a great talk.
Rachel also scored some excellent networking time with Massimo, including connections that will be very useful in her upcoming trip to the Rome Maker Faire. Jim brought home a newly autographed Arduino that had run the dollhouse at Rachel’s New York Maker Faire booth.
(Thanks to Drew Fustini from PS:1 for the lead picture!)
Pursuing her passion for making technology accessible to girls, Rachel Hellenga inspired a whirlwind project to automate a dollhouse. After the smoke cleared, the one-room dollhouse she and Jim W and Bill P built was a miniature version of – and is now displayed within – the “Circuit Castle” she’s showing at the New York Maker Faire. Read her Make Magazine blog post about it.
The Dollhouse Automation System powering it is a collection of small, cheap microcontrollers in a simple network allowing sensors (push buttons, motion detectors, light sensors, etc) in one part of the house to control actions (lights, motors, sounds etc) in another part of the house.
Here are some gory details of putting that system together.
Here are some pictures from the space the night before Thotcon. Quite a few of the boards had been poorly soldered during manufacturing, and we had to do hot-air rework on them to get them to work. Rudy was the hot-air magic man, but there were a bunch of people working to process all the badges.
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: