Plastic Gear Minimum Size

[Mike]

What is the minimum size requirement for plastic gears (specifically Delrin) with at least 72 teeth? I have tried twice with water jet and wire EDM have been rejected both times. Is there a spreadsheet or mini-program available for gears that shows teeth number, thickness, material, diameter, and available toolsets?

Thanks,
Mike

[Tech2]

We don't have a spreadsheet. Waterjet is not recommended for small gears. In eMachineShop for small gears generally you should use Wire EDM for metal gears and Injection Molding for plastic gears. Both can go fairly small. What size do you need? What error message did you receive? What is the application?

[Mike]

I guess I can use injection molding to make the gears (they are 4 and 4.5 inches in diameter) but what machining process can cut a 1/16th of an inch slit through them? I will need a minimum of ( 1/16th width slits that are 1-inch long cut through the thickness of the gear (0.25 to 0.5 inch thick) in a specific pattern. I am getting error messages that say the tools cannot cut that small. I have even tried laser but it wasn't recommended because of the heat generated. Are there ANY tools that can cut very small things into or through plastic? The gear MUST be plastic for low friction and low magnetic susceptibility/permeability.

[Tech2]

Injection molding and Wire EDM can handle such a slit. As for the messages you are getting you should use Help | Troubleshooting so we can see the design file.