Here's a guy doing just what the title describes, with his 3d printer and a furnace.
http://www.thingiverse.com/thing:55415

I have an electric furnace you can use in your garage, can be used to melt small quantities of aluminum just for this purpose. :cool::D:P

Jeff, when I was looking for the hemispheres, I inquired from different companies and a casting hobbyist. These answers all this is a very difficult casting with danger to tensions and cracks. I heard of Keshe, when I was in Ninove, they made the prototype in the Netherlands because many others had refused this, now I have stainless steel hemispheres it seems no longer necessary to have it in aluminum. But do you have experience with such forms?

Quote from geert8550 on February 28th, 2013, 07:16 AM

Jeff, when I was looking for the hemispheres, I inquired from different companies and a casting hobbyist. These answers all this is a very difficult casting with danger to tensions and cracks. I heard of Keshe, when I was in Ninove, they made the prototype in the Netherlands because many others had refused this, now I have stainless steel hemispheres it seems no longer necessary to have it in aluminum. But do you have experience with such forms?

Hi Geert, yes I have experience in casting aluminum. Never had a casting crack on me. The problem is the porosity of the casting, hydrogen bubbles trapped in the casting. With exact melting temperatures and fluxes used, the bubbles are greatly reduced to come out with a really good casting. I have not done this as of yet, because most of the castings I have made did not have to hold pressure or a vacuum. But what you are asking can be achieved with the use of an electric furnace, here
 http://www.amazon.com/Bertha-Compact-Electric-Resistance-Furnace/dp/1878087339  

Here i a video I made of casting aluminum.
/watch?v=S_18UHdlfM4

Wow .. the PLA works better for casting than I thought.  Do you think the sand is basically plugged up with the pla after casting?  
lol I wish I had time to build a furnace.

Nate

Quote from firepinto on February 28th, 2013, 12:27 PM

Wow .. the PLA works better for casting than I thought.  Do you think the sand is basically plugged up with the pla after casting?  
lol I wish I had time to build a furnace.

Nate

Actually what you would do is, completely cover the PLA print with plaster or some equivalent, leaving a hole to pour molten metal through. You would then place this into a controlled  temp [electric] furnace, which will melt and vaporize the PLA into ash, blow this out with air pressure, then place the empty mold in sand to pour molten metal into. It's the same as lost wax investment casting.:cool::D:P

Here is an addition of how to do lost PLA investment casting of aluminum
http://3dtopo.com/lostPLA/

Quote from Jeff Nading on March 1st, 2013, 03:56 PM

Here is an addition of how to do lost PLA investment casting of aluminum
http://3dtopo.com/lostPLA/

I found a video from the same company, pretty cool stuff.

https://www.youtube.com/watch?v=WWVVSZP3Au4&feature=share&list=PLsTTMlAkvVMMxUNHUcXiQxPFxHOU68DWN

Quote from firepinto on December 15th, 2013, 05:44 PM

Quote from Jeff Nading on March 1st, 2013, 03:56 PM

Here is an addition of how to do lost PLA investment casting of aluminum
http://3dtopo.com/lostPLA/

I found a video from the same company, pretty cool stuff.

https://www.youtube.com/watch?v=WWVVSZP3Au4&feature=share&list=PLsTTMlAkvVMMxUNHUcXiQxPFxHOU68DWN

Awesome video Nate, exactly as I would have cast a part as well, with the lost PLA investment process.:cool::D:P