View Full Version : Where to find internal gear?

08-30-2012, 08:52 PM
Just registered on here, looking for some help. I'm in the process of designing a a new base for my arm and I'm seeking an internal ring gear with an outside diameter less than 4.5". I've found a couple listed online but they're all over a $100. Does anyone know where I could find one cheaper? Any help would be great

Here's a picture of the style of gear I'm looking for

01-25-2013, 09:20 AM

Try: http://www.sdp-si.com/estore/CoverPg/GearClamps.htm

They have just about any size (inch and metric) and material (metal and plastic). Bit hard to navigate the website and catalog however.


01-25-2013, 12:15 PM
What tooling do you have access to? You may be able to hob one yourself Or, if you don't need a high-tolerance fully involute profile, mill it yourself. Or, if plastic is OK, send it out to a laser cutting service (Pololu has one, for example.) Or, again if a big kerf is acceptable, use a water jet cutting service ("big blue saw" for example.)