Hi all,

I'm trying to design a 28 teeth POM gear for an education project. We'll need about 3,000 units, so we decided injection moulding is probably the best way to go. I have several questions:

1) The injection moulder's draft angle is 4 degrees - is it too big for POM gears?

2) I have produced a drawing sheet, but I can't seem to specify the draft angle. Is it typically acceptable to specify the draft angle as a note?

3) Usually, what tolerances are acceptable for POM gears? Is 0.05mm (linear? angular?) too tight?

4) Are tolerances usually specified for each dimension or stated as a note on the sheet?

5) Are fillets needed around the teeth?

Here's the sheet so far:

Does it look adequate for manufacturing?

Any help appreciated.

**EDIT:**

A 4 degree draft angle is too big, so I'll find a manufacturer that can do 0.5 degree.