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Fastening two parts using snaps without undercuts

Fastening two parts using snaps without undercuts

Fastening two parts using snaps without undercuts

(OP)
Does anyone know of a way to snap two molded pieces together using snaps without having undercuts in the molded parts?

RE: Fastening two parts using snaps without undercuts

YES!

Several ways come to mind.

But you have not supplied enough information for someone to help you.

RE: Fastening two parts using snaps without undercuts

Can you have a hole in the part at the snap locations.
If so then you can core it out.

if the snap feature is on the ejector side of the part,
then come down with the cover side steel in the undercut area.

The portion that was undercut in the ejector, will now be formed by the cover side.

RE: Fastening two parts using snaps without undercuts

(OP)
TheAnswerGuy,
I was thinking of a simple rectangular box, open on one end, split through the middle where the match between the two needs to be good and I would like to try and stay away from putting to much draft on the walls.  I was just wondering if there were any ways to snap the two together without using any slides, lifters, etc.

Thanks,
Jeff

RE: Fastening two parts using snaps without undercuts

I too have a similar issue.  I am looking for a way to secure a rotary actuator to a separate plastic housing using only snap or clip features, without undercuts on the housing part.  Can send pictures if it would help.  For you clip and plastics experts, this should be an easy one???

RE: Fastening two parts using snaps without undercuts

Maybe you could mold the undercuts without any side action.
Maybe it would flex open when ejecting the part.
Depends on the material you are using and how much the undercut is.
Talk to your material supplier and I am sure they would be able to help you on this.

RE: Fastening two parts using snaps without undercuts

Falcon22,

You have made the scenario much more interesting by not using side actions, lifters or near zero draft.  I don't know which polymer you are working with?  In one respect, if this box were manufactured using Polypropylene, I would suggest that you look at some closures that are commonly used on consumer products.  You will notice that the snap-fit is accomplished by "Bumping" the component out of an undercut.  I have designed and built tooling to bump-out undercuts on materials as tough as Polysulphone.

I would also suggest that you go to www.google.com and do a search on "snap-fit".   

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