Newbie looking for advice... is this possible?

Hello, first time poster here. I've been a luthier for 20+ years and am looking for a way to manufacture my own custom made hardware. See the pic below, is this something that would be possible using a greensand mold? I'm only looking to make the chrome plated portion as I already have the screws and brass saddles. I'd like to use brass and copper to form. I'm curious what kind of tolerances I could expect with a mold like this. Any comments are greatly appreciated.

 

Thanks, for reference that part should be around 2.5 mm thick.

 

Agreed that is pretty thin to be sand casted. If you don't mind adding thickness it would be doable. Might even get away with having that big slot in the pattern too.

 

If the corners do not have to be round like pictured, you could design it in CAD. Send a dxf file to someplace like sendcutsend. Bend up the flanges in a vice then weld and grind the corner walls.

 

I will comment on the two metals I have cast: I think the part could be cast in iron and aluminum 2.5 mm thick with the diagonal window as shown. After getting some advice here, I recently cast 50 pieces of aluminum 1/8” thick and more complex than that part. The key seemed to be pouring fairly hot. Similarly cast iron will run well and fill thin parts if the mold is set up properly and gated adequately.

Here are a couple pics of pairs of aluminum parts still attached to gates, runners, and sprues.


Here is a cast iron box about 3x4 inches and 1/8” thick.


If you are going to the trouble of casting, my guess is the parts will have some sculpted relief and not be just plain boxes. Otherwise, why cast? I am also guessing that iron and aluminum are not, for aesthetic reasons, the metals you would choose.

If detail rendition and surface finish are prime considerations, sodium silicate-bound molds might be worth considering. The Aluminum parts were done in Petroband and the cast iron part was in green sand. Both parts were cast as “functional” parts, not decorative.

Denis

 

How about a non-investment type metal casting plaster like Hydroperm? It seems like a fairly simple process which should yield good detail and an excellent surface finish. However, I've never used it so I can't make a recommendation one way or the other. I'm curious, has anyone here has used a product like this? And if so, what are your thoughts on the product and process?

 

Casting this would be a pain in the ass but doable at 2.5mm.

 

How about “lost PLA”?

3d print them, then investment cast them with a bit of vacuum applied.

I haven’t done this before but search out the technique on YouTube. It looks very possible.

3D printers are getting cheaper and cheaper, and if you don’t have one it may not be hard to find someone close that can print it for you.

DIY cheap vacuum pumps and chambers are also not nearly the hurdle one might think initially.

hardest to source/most expensive part may be the investment “plaster” this is likely the most critical part, plaster of Paris likely wouldn’t cut it.

 

Cast would never have the strength as that stamped part.

 

Lost pla is quite involved for someone new to casting. Sand casting is cheap, investment casting is not, at all. Not to mention hed have to match that part exactly in 3d software - another separate skill.

Best bet for something like this would be machining, which after all the equipment and time needed for lost pla wouldn’t be that much. Just a press and a drill. Now if you want to get creative and have art on the thing thats a different story, in which sand casting might be the way to go with some slight modifications to the part.