Some more details here.
Who says gears have to be round? Here’s a clip of some gears we just made.
And tesselating lizards!
We’ve mapped out a wiring diagram and rough layout for an Arduino-controlled Minecraft landscape. Bill has graciously agreed to write the code. Rachel roped in a bunch of newcomers to build part of the set and brainstorm Minecraft “events.”
We settled on a line of light-up Redstone dust (red LEDs in perforated boxes) leading up to a tree which catches on fire (LEGO flames will stick out of the tree). Then a second tree will catch on fire. We’ll be working on it at Workshop 88 the next couple of Thursday evenings if you’d like to stop by and contribute your Minecraft, LEGO, and/or Arduino expertise. Come play!
We’re gearing up to display this at the Barnes & Noble Mini Maker Faire, along with some other projects. Scott Wojton from the Naperville store has been out to the space a couple of times and has been very helpful to us,so we’re happy to be showing stuff at his Faire Nov 6-8.
We have some great news! Workshop 88 will be able to offer the Teknistas Inventing Lab programs free of charge in 2015–the $330 Tuition and the $100 materials fee will be covered by a grant from Cognizant Making the Future program. In addition, we have opened up the age range to include 8- and 9-year-olds due to the enthusiastic participation of some young but crafty and creative kids at our September preview workshop. The girls will start with a Halloween project and I can’t wait to see how they light up their costumes, make candy glow, decorate their front doors, and invent other things we haven’t thought of!
Just as a reminder, the LED Circuit Crafts program that will be held Wednesdays 4:30-6:30 Oct. 7-November 4. If you have a daughter age 8-12 who loves crafts, please encourage her to apply for one of the remaining four slots.
I’d love to see girls in our community take advantage of this great program while the cost is subsidized by a grant. We need your application by Monday or Tuesday of next week at the latest.
Click on this link to download the brochure & application (you can disregard the tuition & materals costs):
P.S. Some parents have expressed interest in trading pick-up vs. drop-off duties so we can put families in touch with each other once we finalize the admissions.
The dead laser cutter donated to us by Inventables after blowing one too many power supplies is running! While not yet ready for prime time, a water cooling system in a bucket and a fume exhaust thru the flue from the old furnace allowed first tests. The Shapeoko laptop hosts the RetinaEngrave software that makes it look like a Windows printer.
We’re still getting our feet wet with laser power, speed, number of passes, raster vs vector operations, but we’ve actually cut some paper, wood, and plastic. This wolf head – courtesy of Google Images – adorning a circular saw push stick was the first actual cut.
Daniil had the honor of being the first to produce an actual useful object on the cutter. We think his daughter will be thrilled with these laser cut, hot air station formed goggles for her skateboarding doll. She’s been trying to get some for a while now.
There’s still a lot of work to do making much more proper implementations of cooling and exhaust systems. We need proper electrical connections to guarantee the cooling will be running if the laser is on, and a damper on the exhaust pipe to keep cold air out and the landlord happy. Lots more Ts to cross and Is to dot. But it’s actually cutting stuff and hasn’t blown up yet!
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 is thrilled to announce the Teknista Inventing Lab – a nine week program for girls ages 10-12 who are interested in combining crafting with high-tech tools.
Where: Play Moore Studio in Wheaton, IL
When: Wednesdays, 4:30PM-6:30PM from September 16 – November 11
Maker Madness Session Dates:
Monday October 12 (Columbus Day), 10:00AM – 4:00PM
Saturday, November 7, 10:00AM – 4:00PM
How much: Tuition: $660 Tuition is $22/hour for 30 hours of instruction including
the Maker Madness sessions. Family members are
invited to participate in the factory tour at no charge
Lab Fee: $200
Early bird discount of $100 by August 31.
Updated information and application
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.
Our hackerspace had purchased a Kossel Clear Delta Printer. In retrospect, it seemed like it was a forever project getting the printer assembled and operational. For months, it was in the box in the back room with lots of talk about putting it together but no action. One of our senior members, Andrew, had finally had enough. He grabbed the kit and spread it out on the table in the front room of our space.
Well, once the pieces were just laying out there, it was sort of like a jigsaw puzzle just asking to be put together. Like moths drawn to a flame, hackerspace members contributed and we got it assembled over the course of a couple of weeks. Actually, in hindsight, it’s somewhat amusing. We have our open nights on Thursdays and we frequently have guests come in to check out the space. It seems like they couldn’t resist the jigsaw puzzle effect either. Everyone enjoyed the assembly process.
Unfortunately during the timeframe we were assembling the Kossel, there was some major cleaning/rearranging taking place due to renovations in our back room which caused things to be moved around the space. The Kossel was basically done less the extruder which was in a box along with the laser cut outs. The extruder portion of the kit had basically vanished. (We surmised that scrap cutouts from the kit were in its box, so it might have been inadvertently thrown out with the trash).
We debated what to do. Did we actually get the extruder portion with the kit? (Yes. I remember laying hands on the pressure fittings, so it did come with the kit) So do we order a replacement kit? What?! No! We’re hackers/makers! We’ll make a new and better one!
One of workshop 88’s friends, Ryan who periodically visits and has a Kossel Clear, suggested we try out http://www.thingiverse.com/thing:245677
This is actually a very clever design; it uses part of a paper clamp (binder clip) to tension the bearing against a hobbed gear.
There a couple of minor features in this design that I thought could be improved on. I’ve seen Bowden-style extruders where there is a pressure fitting mounted on the input side of the extruder (The Kossel Clear extruder we misplaced had that feature). Having a PTFE tube on the input side offers lots of options on how to route the filament of the extruder. In addition, it seems like the post that supported the bolts to the Misumi 1515 frame could have could have been beefed up a bit as well.
The thingiverse file only included the STL’s, which I loaded into Freecad. Below is the original base as part of assembly. Display properties of the original files where transparent so it was easy to wrap a new solid model with the same proportions over the original model with the new features I wanted.
Here is the base with modifications:
Initially, I had donated a spare MK7 hobbed gear that I had made for my Rockbot printer to the space for use on this printer; but the short length of the MK7 gear caused some problems(which you can sort of see in the assembly drawing) The setscrew I used protruded from the wheel and was contacting the 608ZZ bearing. Another issue was with the wheel itself: it was a not my finest work. The set screw hole overlapped the hobbed portion of the wheel.
I set out to make a new one.
First thing I did was turned down a piece of bar from the scrap bin and sized the hole with a 5 mm reamer.
The blank was then mounted on the stepper motor and basically marked to where it should be hobbed.
Next step was to hobb the blank using a spin indexer. I used a 10-32 tap to do this and Unfortunately, I didn’t have a R8 collet of the correct size to grip the tap… So I put it in a drill chuck and hoped for the best, i.e., that the chuck wouldn’t get sucked out of the morse taper.
The spin indexer really does a nice job of hobbing with a tap and I was very pleased with the result.
After that the cross hole was center drilled, drilled and tapped.
Afterwards, the part was cut off from the bar with a parting tool.
And here is an image of the finished unit assembled.
So far I’ve been exceedingly pleased with the performance of this extruder but there are a few things that need to be addressed before the mod can be considered done.
One issue that annoys me is that changing the filament is more difficult than it needs to be. I was having difficulty getting new filament to feed through the tiny hole in the lever arm. It seems like there is enough room to add some type of tapered pilot hole to help make feeding the filament a little easier. Also, it seems that lever arm has split along the holes of the spring. (This part was printed in our space’s original printer, a Makerbot Cupcake. The Cupcake has seen better days so I’m thinking this separation was more of an issue with extrusion settings vs a design issue) Even so, it should shouldn’t be too difficult to increase the strength around the holes slightly.
The modified design I created needed to have portions ground away with a Dremel tool for clearance. I didn’t take into account how the the filament would push against the bearing. (I was under some time constraints to get the printer ready for a STEM event I was attending, so I wanted to get this project operational vs perfect). The model I had cloned was originally drawn in metric, so was pretty easy to duplicate the nominal dimensions, but I will need to increase the clearance on the stepper motor pilot bore as well.
I’m also currently designing/building a custom Kossel Style Delta printer I’m calling the Wedgie. It’s a fun but slow-to-finish project for me at the moment. It’s uses Kossel Clear proportions and rail arrangement as a starting point. I’m adding some interesting features as well as incorporating the next iteration of the extruder design that was used for this printer.
The calibration of the Kossel Clear seemed like it was more painful that it should have been. This is the first Delta style printer I’ve calibrated and it was a bit of learning experience. I hope to share these insights in a future post.