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