John's Musings

Yeah, Me Neither

Printing on Eggs and Shit.

So I've got a couple 3D printers and a vinyl sign machine and I'm always looking at related forums and reading the industry magazines. One day on I stumble across the Sphere-O-Bot which shows a 3D printed frame with a couple of NEMA 17 motors and an arduino. And I think "I have to make that". Forget that I have absolutely no reason to print on eggs or ping-pong balls but just as a man climbs Everest because it is there so it is with me.

There is a kit from a place called J-Robots or you can source the parts yourself. The software is open source. The thing is that an Arduino Leanardo, a Brainboard, and two stepper motors and drivers will set you back over $60 maybe more with shipping. Then you need the hardware and the other related stuff. Might as well get the kit.

However, I'll say this up front. IF PRINTING ON EGGS IS SOMEHOW IMPORTANT TO YOU......... buy a bigger kit. This barely and I mean barely holds a Large egg. In fact some of the eggs I have won't fit. I always buy the largest ones in the store. There are bigger kits out there. Same stuff, just it holds bigger items.

Here's another gotcha. I could not for the life of me get the Arduino software to load or the Inkscape plug in to work on Mac Sierra. Everything works perfectly on Linux Debian. I can't speak for Windows but Mac wasn't working right.

Another caveat is that when I was looking at the J-Robots kit they didn't have the 3D printed parts available. No problem, for me BUT the frame takes about 13 hours to print. But it looks mighty nice when it's all said and done. If you print this frame you won't need to print with supports. Brilliant. Get the rest of the parts here, except for the frame of course.

The other parts can be zipped off in an hour or so. Here's what it looks like assembled with the help of my poodle model.

Assembly is pretty easy but forcing the suction cup on the left side into the fitting was no fun. Follow the software installation instructions here. For me it was literally just unzipping some files to my extension folder for inkscape from here. For mac and windows there is an installer but again it didn't work for me under Mac Sierra.

Setup is a little un-intuitive but if you've successfully built it you'll figure the rest out quick enough. I screwed up only a couple of eggs before I got great prints. So there is a learning curve but not a big one.

Here's a video of me printing over some screw ups with a geometric pattern.

And finally here is a video showing the whole device in operation.

I have a few things to figure out still. I can easily see where tinkering with positioning, pen height, different types of pens, etc. will make a huge difference in quality.

So until I figure out what to do with this thing I do know a few people with little kids and Easter is coming up! Okay, okay, I wasted a hundred dollars. Sue me.