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Small Plastic Parts Answered

I've seen some forum topics here that explain how to create your own plastic molds etc. I'm looking for some help here. I need to make some small plastic gears, but I'm not sure that investing the time and effort into learning injection molding, simply to produce a hand full of parts, is sound logic. Is there anyone out there that makes small plastic parts for a living? I've contacted several companies in my area, but they won't do anything less than 10K quantity... Thanks, Tim


Plastic gears can be duplicated by using epoxy to produce a cavity mold. The cavity mold is then used to form plastic that is heated to a soft gel and allowed to cool in the epoxy cavity. When cool, the formed gear is removed and more heated plastic added. The more you see what you can and cannot do with this the better your result. I use the green stick epoxy glue to make small molds like you have. Nylon , cut to a close fit will heat and soften with a heat gun. Try it, I think you'll like it.

Wouldn't it be easier to use existing gears? Either purchased especially, or ripped out of old toys, printers etc.

That's what I'm currently doing... but it would save me LOTS of time if I could manufacture them myself or find someone that's already set up for this type of work. I use about 10 sets of these gears a week. Thanks.

I'd say use better gears, maybe all metal ones?

Goodness, what are you making?

I've just thought - what about laser-cutting? A company like Ponoko should certainly be able to produce the yellow (single diameter) gear for you, and maybe the red (double) gear could be made by glueing two together?

The size of the gears, you could get hundreds out of a single sheet of material.


9 years ago

how many were you looking for and what can you afford?

I'm not making anything, just repairing lots of these gear boxes. These are tiny gears from a lens unit. I don't have access to a CNC machine, or any plastic injection molding etc. I've contacted several companies here, but they expect me to make a minimum purchase of about 10,000 units... The ideal situation would be to find someone with this machinery that would be willing to make a mold and produce a thousand of each.

Ponoco isn't cnc or moulding - they're a laser-cutting company, and can do one-offs.

If you have access to a small CNC mill, you could fairly easily carve your own out of nylon.

I'm not so sure, those gears are incredibly tiny... You'd need a ridiculously tiny CNC bit to mil these... Not to mention the high speeds would blow the weak nylon to little tiny bits.

A CNC mill can be made any size, and the bit would of course be turning slower. Different materials require different speeds and different bits.