lego like press fit injection mold design

[anchange]

Hello I'm trying to learn injection mold design. I've done 3 molds so far with good success. The next two pieces I want to make will mate together. I want to use a pressure fit where the parts can be attached and detached easily exactly like two lego pieces. What are the specs on a basic lego piece to allow for the fit? How many thousands larger is the male cylinder in relation to the female hole? Any help would be greatly appreciated!

 

[MikeHalloran]

Legos don't mate cylinder to hole.

They mate cylinder to array of hollow cylinders, tangent circle to tangent circle with a little interference.
.. which makes the tolerances somewhat easier to hold, but I don't know what they are, exactly.

It's time for you to buy some Legos to measure.



Mike Halloran
Pembroke Pines, FL, USA

 

[anchange]

Got a lego piece and you are definitely correct. I'm having a hard time measuring with my calipers looks like maybe a thousandth? Maybe I'll try sanding off the fillets and then flat bed scanning the piece. Anyone have any insight?