Do I need a company to do a one-off insert for a MUD base?

[Effcap]

Hello, not an engineer but learning enough to be dangerous. We have a small plastic part (.75 x .25 x .33" in PC resin) that ties an assembly together. It has a very simple rectangular shape with a single hole in the center. Could we avoid the high cost of an injection mold tooling company ($4800 - 5800 quotes) and have a competent machine shop CNC the aluminum insert mold plates for use in a small MUD base? The bases are relatively inexpensive and we can use them for other small parts we'll need in the future. There are a lot of injection molding companies here in SoCal that could then run the parts for just the setup and cycle time cost. Am I way off base or is this entirely feasible?

Thanks

 

[Pud]

Yes. Quite possible, but here in the UK this sort of set-up is usually more pricey than a dedicated tool. The system seems to me to be lacking in rigidity but that's my personal take. I know lots of people use them.
Don't forget you'll have to put in the ejection system as well as machine the cavities.
You could try and find a moulder with a MUD base already?
One possibility might be to use a standard steel bolster and put changeable cavity inserts in it - either alloy or steel. We have several in hand for small volume jobs.

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[Effcap]

Thanks Paul, what do you mean when you say the MUD system is "lacking in rigidity." Does this mean the part itself could suffer in accuracy from part to part or that system in general may not last that long?

Thanks again

 

[Pud]

Both really - the plates are (to me) too thin and the ones I have seen/used also have small diameter tool half location pins. We recently had one set of cavities/ejection system converted to a complete tool. Was cheaper than buying a frame.

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[MikeHalloran]

MUD? You mean multicavity insert molds, where you buy just the insert, and N parts for different customers are made with every shot?

I've bought a lot of scrap from those things, and very little acceptable product.

If your PC part really is as simple as you describe, consider having it CNC milled from sheet directly, with no mold involved.





Mike Halloran
Pembroke Pines, FL, USA

 

[MacGyverS2000]

A pic of the part (and tough dimensions) would likely get you a very quick and accurate answer on the best way to create them.

Dan - Owner

http://www.Hi-TecDesigns.com