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Skycam assembly gallery and robot debugging

2012-08-03 Dan

I sold a record number of Drawbots today. Awesome possum! To celebrate, here’s a little bit more about the Skycam I’m going to be bringing to the Vancouver 2012 New Forms Festival, September 13-16. The Drawbot will also be there.

I assembled the Skycam a few days ago. It’s two Drawbots put together with a bit of modified software on top. I assumed I would set up four steppers around a clock face. Each stepper would be at 1:30, 4:30, 7:30, and 10:30. An X+ movement should be towards 3:00 (Berlin), a +Y towards 12:00, and a +Z towards the ceiling. Sounds do-able, but it’s a whole new world of problem solving.

I knew from the start the steppers would be mounted backwards or something. I wrote some code to “jog” just one motor so I can identify which is which and then switch their positions in software. Each motor gets assigned an XYZ coordinate. When my Java program says “Go to XYZ” the Drawbots can figure out the rest on their own.

I also knew that I had to wait for a movement to complete before starting another or accuracy would suffer. That was challenging, and the first time I wrote Listener pattern in Java. Thank you to everyone in freenode#java for their help!

Re-centering a four-string device is a lot harder than a two-string device. I put the origin in the middle of the floor. I still have to manually turn the bobbins which is my least favorite part.

I broke the strings three times already. Lesson learned: run the Skycam with the emergency stop in my lap. Also, disconnect three of the four strings when I’m done with the robot for the day so people can’t get snagged on it by mistake.

So how’s the actual movement, when everything else is said and done? Well…so far the results I get are really confusing. They have to be seen to be described. Anyone interested in a video? Comment now or forever hold your peace.

For a complete description of the build process, read the descriptions and titles of each picture in the gallery. I make no apologies: I have Burning Man on the brain.

If you’d like to build one of these Skycams, let me know. I can package up all the parts if you can get the 2x4s and the drywall/wood screws.

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CNC Life Tree Work Finished, Drawbot disappointment

2012-08-01 Dan

I spent the last three days in the garage using the CNC machine and a couple of jigsaws to make 100 cut wood patterns for a burning man project. They swear up and down they’re going to tell everybody about my service so I hope that will translate into paid work. (@$60/h+setup consultation)

We got a really good Kanban rhythym going with the jigsaws. Teams of two on a temporary table made out of sawhorses. One would hold the wood, the other would hold the jigsaw. The wood stays as still as possible and the jigsaw turns. When the jigsaw gets to a wierd angle for one user, we’d switch. Each team would do one type of cut (like the exteriors, or just one of the inside cuts) so we’d have to cut the same board two or three times but the speed we were cutting was really great, we could finish a complicated piece in about 2 minutes each, total. Compare that to CNC machining a part that took 40 minutes and left the mill bits covered in blackened glue and gum. Yuck!

I added a few parts to the CNC and it’s running very reliably now. It’s almost enjoyable to use! A proper dust shoe and a good vacuum would really make a world of difference. Before that I’m going to get a fire extinguisher, just in case. Wood table, lots of friction…

Talking with a teacher yesterday I found out their entire annual budget for new class stuff is $100 CDN. No wonder nobody buys a Drawbot or a Cando! I said send home a note with each kid asking for $5 and you’ll have enough for two Candos. The kids who finish work first get to put it together. I don’t think I won her over. So… great product, broke target audience. I’m told if a product can teach enough of the required subjects for a given class year the province will buy that product for every school. I have to think bigger and talk to the school board. Have you got a contact? Are you a teacher? Let’s make this work.

The rest of the day will probably be spent on home renovations. Mudding drywall is my least favorite part. Tonight I’m at the VHS signing a contract and (probably) installing a new eyewash station. Wednesday nights are Kaizen nights at the VHS, when members are encouraged to make a small improvement to the space.

Miscellaneous

Skycam frame assembled, Burning Man Life Tree CNC work

2012-07-31 Dan

I’ve made a cube from 2x4s recycled from a home reno project. On each side I’ve put a drawbot. On the box in the front left corner I put my laptop. The laptop is running custom software that delivers gcode to each drawbot and they’re running modified drawbot code that understands the third dimension. The four strings are connected together at a tool that can be moved with GCODE to almost any point inside the cube. Before I take this project to the New Forms Festival 2012 I’ll be sure to rebuild the cube with some CNC’d corner braces and some property slot-fitted joints that will make it very rigid and aesthetically pleasing.

I built this in my garage while members of the Burning Man 2012 Life Tree project were using my 8×4 BlackToe CNC to cut parts for their burnable art project. Looks like they’ll be in my garage for the next week or so as they cut 100 leaves. Maybe we’ll celebrate at the end with a great big backyard BBQ?

To speed up the manufacturing I’m going to cut one stencil of each of the 4 leaf types. Members will then be able to trace one leaf onto another, drill some pilot holes, and then use jigsaws to cut the rest. Should go much faster than trying to CNC everything.

I’ve got to post to the GVIAS and advertise my skills. It’s great that artists want to make giant wooden sculptures. It sucks that they get an idea stuck in their heads that is hard to build, hard to transport, and hard to setup on-playa. Having worked with a few different groups over the years now I think I’ve developed a bit of experience in this area. By getting involved earlier when the project is being sketched out I could help to build a design plan that meets the artist’s needs and keeps the manufacturing costs to a minimum.

Today’s goal is to get the Life Tree members up & running, finish cutting the templates, and then I’ll be mudding drywall all afternoon.

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Connecting to two Arduinos at once to drive four stepper motors

2012-07-29 Dan

I’m really starting to love Java. It’s so easy! Here I’ve taken the code for the Drawbot and modified it a little so that it will run my new project. From here I’ve got control over 4 motors and it’s no big stretch to reach for 6 or more.

The biggest challenge will be keeping the NEMA17 stepper motors from getting criss-crossed in my new application. I think I’m going to take a page out of the Burning Man city plan and name each motor 10:00, 2:00, 4:30, and 7:30. Then +X will be 3:00 and +Y will be 12:00.

Almost as important as doing the job as advertised, I’ve got to get my robots looking really slick and professional. Appearance and PR are starting to be a big concern – if I don’t market well, I don’t sell, and I need to sell if I intend to keep doing what I love.