Injection molding forum?

I could probably help out a little Ed. I've done a lot of things but one of them was 30 years designing and building injection molds.

I have a post-grad certificate in plastic injection mold design, but John would probably be a better bet.

I would also like to know some small-scale feasibility. I'm paying $25/each for injection-molded camera hot-shoe connectors for which I have found exactly one supplier in the universe.

That's not a bad price if the contacts are inmolded.

I've got a few years under my belt running injection mold presses. Only complete hydraulic, no toggles. Mostly on HPM and Cincinnati. My focus was on running them faster, adding pickers, going to runnerless molds, etc. Not much prototype work.

Karl

--Aha! Looks like RCM is da place after all. Well I'm trying to make a die to make these:

You are aware of the widely available and very inexpensive quick stop clamp nuts:

Or the slightly fancier and more difficult to install version:

Cool.

Steel or aluminum? You planning on unscrewing a threaded bit to get it out?

Have you looked at cast urethane (you probably have a vacuum pump for degassing)?

For a test run you could also consider doing rapid protyping, but it will be a few hundred dollars cost most likely.

Is 1/3-oz enough?

Cute, but the this threaded feature on the Bridgeport is an obsolete analog item. Replace it with a flatted rod and thumbscrew clamp, and measure with a DRO, better/faster/cheaper.

Lordy Ed, I remember when this first appeared in Machine Design! Hope you finally get it off the ground and make some $$ with it!

Jon

--Yeah, yeah, been there, done that. Ever have one slip on you and go .05" too deep? ;-)

--Aluminum. Threading occurs after molding, when two parts are snapped together; makes the making of the mold much easier.

--Yes; have vac pump but want to avoid the step if possible.

--Heh. For my next project I'm going to build a Mendel

--Oh yeah; plenty big enough.

--Different strokes for different folks; I've used the prototype for over a decade: no complaints..

--Heh. Yah, sometimes it takes me a while to get around to something but the time has finally come for this one!

Nope.

In that case, forget injection molding and think extrusion. You've got something that's basically like a big T05 heatsink, so you should be able to extrude as a complete part (no snap together) and then slice into the appropriate lengths.

You could also just lathe and mill it with a 4th axis, taking a solid plastic rod, bore the center hole on the lathe, then put in 4th axis on the mill and mill the fins. A 24" rod should yield like 45 parts.

--The thought has crossed my mind but again it becomes a part best made by experts and the price goes up accordingly. I want to do it all 'in house' so's it becomes more cost effective. Die's almost done now; hope to get some epoxy parts out of it soon.

--Not set up to do this either. Sigh..

Instead of epoxy, do a search for "casting resin" on Ebay. A half-gallon kit is $30 (plus shipping), a two-gallon kit is $80. Much thinner than any epoxy I've used so degassing may not be necessary, hardens in about five minutes, no significant exotherm in small parts, nice off-white color, tough product.

Just a satisfied customer.

Best -- Terry