Yes, even this design can be a FREE download once I am fully funded for my RoboGuts™ S.T.E.A.M. Education Program Kits;

IF each viewer donates just $5 I'll be funded almost overnight and then all my designs become FREE downloads!  

The fastest and cheapest way to get all my .STL files FREE is to donate $5 to help fund school materials ... once I have $3,500 I'll convert all these files to FREE downloads.   https://www.gofundme.com/roboguts-kits-lessons

This is an upgraded kit from the more basic kit I uploaded earlier ... this includes differential gearing so one drum drives the other at a different speed (resolution) to create more beats/revolution and allow for more syncopation ... Yes every part here is designed to be MakerBotable with a CupCake MakerBot ... except for the rubber band ... get those from your local post office! This is another of many entries to the makezine.com/go/makerbot contest ... blog.makezine.com/archive/2010/04/makerbot_giveaway.html Instructions Use the BOM to see how many of each part to MakerBot ... and both the drawing and display images to assemble your 2-ch 2-gear Programmable Percussion & Rhythm Machine. Rubber bands are the springs around the horizontal extensions out to the hammer pulls the hammer back to a stand-up position. Program the drum set by sticking the programming pegs into the holes on the drum ... Set different objects in front of the hammers and crank the machine to hear the rhythm you created ... It's a learning process to understand beats/measure ... then with 2:1 gearing and a 2nd machine you can increase the resolution to 32 beats/measure. BTW, if you store a few extra programming pins inside the drums and you'll have a two more sources for noise ... albeit not percussive but more like a rattles. Adding a servo drive to the back will allow for continuous rotations. Adding a µController will allow you to vary timing turning the motor drive ON/OFF and different times ... there's almost no end to the expandability of this kit. If you successfully make this with a 3D printer please send me the build-file and machine type so it can be uploaded here for others to use.