Mold bases - sprue/runner/gate system

[Wargamer]

We're in the planning process to have injection tools built for a line of small, complex parts. The parts will fit on a sprue/runner/gate system that has dimensions of about 10" x 6" -- total depth is about 1/2" or so (these are small parts)

My question is -- I'd like to get a MUD base and then each time we have new sets of parts, we can have inserts milled to fit that base. Cost wise, though, I am not sure if I should be looking for someone to lay it out so that the whole set is on one sprue/runner/gate system -- i.e the 10" x 6" area I mentioned before -- or if we have two inserts at 5" x 6" instead? Is it cheaper to go smaller -- or does it matter?

Thanks -- sorry, I'm a complete newbie at this stuff!

Thanks!

[dfurlano]

There are many things to consider and many questions you have not asked. Interchangeable inserts are fine but are the knockouts locations the same? Making inserts that are interchangeable can be expensive due to tolerance, size restrictions cooling line layout and O rings (if needed).

Taking the inserts in and out cause damage if you are not careful. Also what types of materials are going to be used. I would assume the same but are the runners and sprue adequate for both? Would you insert the top half also? Is the mud frame strong enough to with stand the pressures of both sets?

Stuff to think about.

Dan

[ZipSnipe]

Probably depends on what your parts look like. Check out a company called DME. I think thats we,re we get ours from.

[toolrm]

Hi, Mudd Frames are useful if the frame is to stay in the molding machine for an extended period of time. This allows for quicker changeovers for new parts in the same machine. The factors dfurlano points out are accurate and zipsnipe is correct that DME does sell these sets. One problem you have with these sets is that if you need to run both die sets at the same time, You have to buy another mudd frame. Personally, I prefer each tool have it's own frame. The cavity and core configurations in my trade vary to much to make them worth it. Hope that helps a tad. Toolrm

[dpryor]

Wargamer, the real advantage to the MUD base is interchangebility and not necessarily cost savings. If you think you are going to be swapping the mold in and out of the press frequently, then MUD might be the way to go. If the mold is going to stay in the press for a few days, then I would go with conventional mold construction.

[MnotLyon]

Originally Posted by Wargamer We're in the planning process to have injection tools built for a line of small, complex parts. The parts will fit on a sprue/runner/gate system that has dimensions of about 10" x 6" -- total depth is about 1/2" or so (these are small parts) My question is -- I'd like to get a MUD base and then each time we have new sets of parts, we can have inserts milled to fit that base. Cost wise, though, I am not sure if I should be looking for someone to lay it out so that the whole set is on one sprue/runner/gate system -- i.e the 10" x 6" area I mentioned before -- or if we have two inserts at 5" x 6" instead? Is it cheaper to go smaller -- or does it matter? Thanks -- sorry, I'm a complete newbie at this stuff! Thanks!

Have you choosen a mold builder/ custom molder yet? These are questions you should be discussing with them. Some molders don't like, or own mudd frames, while others do. It's possible you won't even need to buy the frame, and that would save you a considerable amount of money.

If you plan on putting more than one part in each mold, it's called a "family mold". Those can be complicated to ballance the part properly. They can also be a pain if for some reason you need to run extras of just one of the parts in the tool.

If you'd like to send me some files, I'd be happy to quote building the molds for your project.

[dpryor]

Like Mnot said, a family mold can be very difficult to balance. You may spend more many on scrap parts and press time than you would ever save in mold cost. How many different parts are there? We do mold design and feasability studies. We could layout your options and let you make a decision from there.