Some of the things we have worked on…
Controlling XY table using Ramps 1.4
When the buildlab acquired a couple of pieces of used equipment, it was obvious what needed to happen: building a computer controlled laser cutter/engraver.
A very generous guy named Tim (who already has a nice laser cutting setup) donated a Coherent Model 42 CO2 laser. It’s capable of cutting 1/4″ acrylic and plywood and because of its size, it will be necessary to move the part to be cut rather than the laser. This is where the XY table is necessary.
A premade linear motion table with stepper motors was being sent to the scrap yard by a local company and I was able to snag it before this happened, but the controller that came with it was non functional.
I wanted to see if the motors on this table could be driven using the control circuitry from our reprap printer. Ramps 1.4 (aka RepRap Arduino Mega Pololu Shield) and an Arduino Mega form the brains of this printer. I disconnected the 3d printer motors and connected the motors from the XY stage. The motors on the stage were similar steppers (1.8deg. per step) but have slightly higher current draw. To correct for this, all I had to do was adjust the trimpots on the Pololu stepper drivers, and decrease the run speeds to account for the screw drive of the XY table (vs belt drive for the printer). Then it worked!
Here’s a pic of the xy table:
And here’s the mess of wiring coming from the Ramps board:
To test out its functionality, I attached a pen and loaded the text “Makers Gonna Make” into Pronterface (reprap control software). There was no penlift, so there are connecting lines between the letters. But it demonstrated that the stage worked.
It’s pretty oldschool, check out the inside of the controller:
The last thing to do is to alter gcode instructions to control the laser shutter. This will turn the laser off in all the places where there are unwanted connecting lines. I found a Python program called RepRapRays that basically finds and replaces any extruder commands with shutter On/Off commands. I connected LED strip lights to test whether this worked and it did.
Printing replacement gears for the RepRap 3d printer
The extruder gears on my RepRap machine were getting a little worn out, so it was time to print new ones. The white gears that needed replacement can be seen below:
To get a new gear, I headed over to Thingiverse and found this:http://www.thingiverse.com/thing:97377
Loaded the file in Makerware, and chose print settings that seem to work well. Here’s what it looks like:
Then sent the file to the Makerbot2 printer. The result was nice:
It’s great to be able to print functional parts like this without purchasing anything from a ‘factory.’ These extruder gears will get a lot of mileage pushing ABS filament into the hot end of the reprap printer.
Free, open-source software
Blender is an excellent 3d modeling and animation program that can be used to make models for 3D printing. A quick google image search for blender models will show you the type of professional, amazingly high quality models that can be made. The crazy thing is that its free! There is a pretty steep learning curve but I’m told it’s completely worth it.
At our first Intro to 3d printing class, I told everyone they should learn the software and I was speaking for myself as well. So, here’s my first model, its a business card holder with my wife’s initials:
You may not think that’s terrible until you see something like this from blenderartists.org:
Polargraph drawing machine
A very simple system for drawing with a pen of your choice: a couple of stepper motors, Arduino mega & Adafruit motor shield is all you need. Well also a ball chain from hardware store, converted ATX power supply, 3d printed chain sprockets and motor mounts…and also a ‘pen gondola’ and fastener, and a backboard that we threw together in the shop. And then once the firmware is installed and controller software is running you can get really neat sketches:
This one only took about 7 hours to complete. At the end of the day, we were quite impressed with the performance of the fine tip red Sharpie.
Starry Night coffee table
Had to upload a video of Dan’s work in progress: a fiber optic coffee table. He’s also working on a controller to modulate the colors and frequency of the ‘twinkle.’
The first ‘real’ makerspace project was to build a 3D printer. We chose the Mendelmax 1.5 platform, working from many sources on the internet. One of the challenges of such a community designed project is sorting through all the model versions,variations,revisions,updates, and varying opinions. Now after having done it once, it all makes sense and you get the feeling that it could have been completed it in 1/4 of the time it actually took. But it’s printing now, and we have a little purple octopus to show for it!
Some pics of the progress:
And finally, Mr. Octopus: