How to make collapsible core for deep undercut cores

[din71]

Hi all, I have a core design with deep undercut. We have been making these cores but I was thinking if there is a way to make these cores collapsible. Any help will be highly appreciated.

 

[MikeHalloran]

Are you saying the collapsible core blanks you can buy will not collapse far enough to clear this part?



Mike Halloran
Pembroke Pines, FL, USA

 

[din71]

Yes unfortunately yes, the readymade blanks available here in India are available only for caps moulds. Whereas our part has an undercut of 6-8mm per side.

 

[MikeHalloran]

I'm a little fuzzy on what the image you provided is intended to show.

Guessing, based on my limited and likely incorrect understanding, maybe you could try this:

A collapsible core comprises a central pin and an array of 'leaves' around it, that are pushed apart into the molding position by the presence of the pin, and retract radially when the pin is withdrawn.

Suppose you used a commercial collapsible core to make the smaller neck detail, and inserted that core into a bushing, which would in turn be the 'pin' of a much larger collapsible core set up to make the larger undercuts. That larger core would be a custom part, of course. If it's beyond your moldmaker's abilities, maybe some of the commercial core makers could be enticed to attempt it.



Mike Halloran
Pembroke Pines, FL, USA