This is an OpenSCAD script for the generation of a stepper motor gear set, to your exacting specifications.
I'm sure there's other scripts like this out there, so here's what makes mine cooler than theirs:
... that's about all I got, really. Based loosely on TheRuttmeister's excellent herringbone gear set here: http://www.thingiverse.com/thing:5795
THANKS to the entire crowd on IRC Freenode in #reprap, #makerbot, and #makergearv2.
SPECIAL THANKS to GregFrost for his involute gears script and some special handholding while I was writing this.
There's an option at the top of the script that determines whether you are generating the model to view it, or to print gear1, or to print gear2. Start by measuring your hardware and adjusting the numbers in the script to match. Then generate the model for viewing, checking that everything looks sane. For fun, you can turn on the animate option and watch it spin!
Once you have things the way you want them, switch to generating each gear separately and render them to .STL for printing. Simple!
AFTER RUNNING THE SCRIPT, IT WILL SHARE SOME VITAL FIGURES WITH YOU:
- It will tell you the radius and diameter of each gear; make sure you didn't generate something too big to print! The Large gear .STL I uploaded here is really nearing the limits of my ToM build platform, so ... be careful!
- It will tell you the minimum and maximum drive shaft bolt length it will accomodate. This is the length of the bolt IN THIS PART, so make sure you add it to the bolt length of your tensioner and the space between them, if any. If you are using my script to create your tensioner ( http://www.thingiverse.com/thing:6492 ), that will also report bolt lengths for your convenience.
- It will tell you how far apart the axels of the gears must be (which is hopefully the same amount YOU told IT), for designing your motor mount (I'll be adding this as an option to the above Thing when I have time).
ABOUT THE .STL FILES:
I'm printing these now so I'll be taking photos when they're done. These should be appropriately sized for using a makerbot stepper motor 60mm away from the drive shaft. The drive gear is designed to accept an M8 bolt, to be used in conjunction with the 608-style tensioner STL in the parametric Wade's tensioner Thing.
Hope you find this helpful! As always, feedback is appreciated.