Author Options:

Casting a REALLY complex HOLLOW shape with metal!? Answered

Exactly like casting a 3D print out of metal; I have a airsoft upper receiver which I want to cast out of aluminium cheaply.
Made of polymer and quite complex.



3 years ago

Well.. if you have a direct metal printer this might be a thing. Lost PLA probably won't work for this though.
Mostly for the reasons DownUnder35 noted, but also because there's inherent shrinking and expansion involved with casting aluminum which gets worse as the shapes become more complex (it's caused by the different rates of cooling associated with the differing thicknesses of the metal). You can mitigate some of it by slowly cooling the casting down in a furnace, but if you do that, oxygen content then becomes the main concern. Aluminum can be poisoned by oxygen. This can be serious, but as an airsoft upper, it's probably ok. That still requires you to have a kiln capable of maintaining temperatures close to a thousand degrees for many hours at a time on top of the 3d printer and the aluminum melter.

A block of aluminum and a home CNC machine are the better choice here really.

Thanks; I don't want to rent out a lathe so it won't really work well, but thanks anyway :)

Maybe there is a way to paint the polymer on the outside with molten aluminuim to create a solid hard finish, that way it doesn't scratch and might not bend as easily.

Did you consider a resin cast?
You still need a proper mold but
if you use the right resing and mix fine carbon fibres it in the
resulting product is quite strong.
For obvious reasons the use of a
vacuum chamber is a must with complicated parts like this, same for
making the proper channels to get the resin in and the air out.

gadget accompanies 2GB RAM and 8GB Flash stockpiling. Second screen abilities
are accessible to Kindle Fire top media box Amazon Fire Tv proprietors, and a remote control incorporates a
mouthpiece for voice look.


You better off making a solid cast and to drill it out using a lathe.
The thread you would have tap anyway as casting won't be fine enough to make it work.