Snap fit design with no clearance between mating parts 2

[renasis]

Hello,

I am working on the design of a cantilever snap fit(see attached images). This assembly will be permanent(no dissassembly) and I want the parts held tightly together so that there will be no vibration. I have read some online documentation from BASF and Bayer, but was not able to find anything that addresses this specific issue. My thought was to shape the underside of the head so that it forms a hook(see images), but I am unsure if this is the best way to address this. Does anybody know where I could find more information about this?

Thanks,

- ren

 

[MikeHalloran]

What images?


Mike Halloran
Pembroke Pines, FL, USA

 

[renasis]

Mike,

I posted the links below.

http://files.engineering.com/getfil...4864-4d4e-a0c1-83d8a1233b33&file=snaphook.pdf

http://files.engineering.com/getfil...7906-459e-affe-07682764b63c&file=snaphook.pdf

Thanks,

-Robert

 

[loughnane]

I think a hook would be a nice idea assuming you can strike the balance between it being meaty enough to hang on during your max load/vibration yet small enough that it doesn't overstress the base of the snap arm during installation.

If it's truly permanent you might want to looks at a layer of vhb on the (per your image) right side of the snap arm. That way you have a nice broad area of attachment instead of what looks to be a pretty small snap arm.

Just some thoughts

Chris Loughnane - Product Design

http://www.pdnotebook.com

http://www.twitter.com/DesignNotebook

 

[MikeHalloran]

A hook will make it difficult to disassemble, but won't prevent it from rattling, and guarantees that there will be clearance with which to rattle.

It might work better to reverse the slope of the line so that the remaining preload in the tang works against that face to draw the parts together. A more nearly horizontal slope will make it harder to just pull the pieces apart; you can probably work out the slope and the friction coefficient so the tang breaks before disengaging under tension.



Mike Halloran
Pembroke Pines, FL, USA