View Full Version : RFQ: Need a prototype machined

04-13-2011, 10:08 PM
I'm looking to do a short production run of this part in cast urethane so a need a master part to make the mold. I would prefer to have it machined out of Aluminum. Size is roughly 2" diameter x 1" long. I would like an initial quantity of one. I would also like input on potential ways to reduce cost. I have the native Solidworks file, iges and stp.

04-14-2011, 12:36 PM
We'd be happy to look at your project. Please email your SolidWorks file to info@davidwolfedesign.com .


04-14-2011, 09:14 PM
After you get your 1 model, are you wanting to cast a lot of these? I make spin cast molds and could cast the urethane, is this what you mean by "potential ways to reduce cost" ?

04-15-2011, 08:22 PM
At this point I was just going to do a small run 10 or so. Not sure how cost effective that would be with your process.

I'm open to any ideas of cost reduction though. Whether it's with better casting methods like you suggested or actual physical design to reduce machining cost.

What are the typical cost for spin casting? How many units would I have to do to be cost effective?

I'm try'n to hit a cost point of $20 each to recoup my machined prototype cost, and mold material cost.

04-16-2011, 09:10 AM
Spin casting would be more suitable for runs of 1000 or more.
What casting process are you planning on? RTV?
If you only want 10 or so, maybe they all should be machined out of urethane.

04-16-2011, 10:34 AM
Yes, RTV.

The reason for cast urethane was cost, my labor is free. I can do the casting myself. I'm not sure machining urethane would help me. The machining labor is the killer not so much the material.

04-18-2011, 08:57 PM
I might be all wrong here, but I believe that getting 10 each cnc milled from urethane is not going to cost all that much more than getting 2 made from Al.

The labor is mostly in the setup and non machining time. There really isn't all that much more labor to making 10 vs 1.

For that matter, my experience is that 100 often isn't all that much more than 5. The economy of scale of cnc is enormous.

If you really just need one, I suggest finding a buddy that has a manual mill setup and make it on that.

04-18-2011, 09:27 PM

If that's the case, I would love for shop to make me that offer :) or just confirm what your saying. If my final product will be urethane anyways, it would save me the hassle of going through the casting process.

04-22-2011, 06:41 PM
Hi, I am just curious. Did you design it with the intention for it to be milled, lathe cut, etc ? The more sides it needs to be machined from, really add to the cost structure. In a perfect world, you try to design a part to require at most 3 axis cutting, maybe 4 if you can, with no remounting on the tool.

This is easier said than done of course.

As I said, I am not an expert at this at all, but it seems like that part needs machining from every side, and it will need to be re-mounted at least once no matter how it is done. Any simplifications will help with your cost goals.

04-23-2011, 11:42 AM
I did keep the conventional machining techniques in mind but you can only do so much before it starts negitively affecting the design. In the end I did make some compromises but it's still not simple enough to do on one machine (i.e. a lathe) or be machined without remounting.

Those are definitely sound design techniques, I appreciate the insight.

04-23-2011, 12:01 PM
I'm going close out this request. I got 5-6 quotes, 4 of them were very reasonable so I'll be make my decision very soon.

Thank you to everyone who took the time to provide a quote.