Metal Casting - Lost PLA method

I was contacted last night by a man who owns a local foundry. He is interested in the lost PLA method. http://3dtopo.com/lostPLA/

I'll be making him some sample parts this week. I'm pretty excited to give it a try!

Hopefully things will go well and I'll get a blog post up with more info.

 

That is very interesting I was impressed that the PLA was literally gone I would have expected some other residue but I guess 1200 degrees does the trick. It was interesting to see the printed lines of the PLA on the metal casting extreme detail.

 

Yes. It is investment casting. The same process used to make a lot of things. The difference is the use of 3D printing to make the mold positive.

Investment casting is just a pour of molten metal. No pressure involved. Same as sand casting from the perspective of the metal. I'm pretty sure that most dental molding use something like this.

Die casting and thixotropic molding both inject molten or semi molten metal under pressure.

 

The meeting Saturday went really well. Both myself and the guy with the foundry are both on board for developing a service to provide makers with a method to convert their 3D printed parts (or 3D designs that we will print for you) into cast metal parts. We should be able to do this for quite a bit less than having the part 3D printed directly in metal.

I have a picture of the first part, but I have to preface it with some details.

Our plan going into our meeting was that I was going to give him some scrap pieces to play around with as well as high quality print of a part for a steam engine kit he is working on. One of the scrap pieces was a little Make Robot (http://www.thingiverse.com/thing:40212) that I had scaled down and printed as 1 of my first PLA parts. I didn't even adjust any of the slicer settings on this guy. I had printed it in ABS the night before and just reran the same GCODE with PLA. So, the print quality is kind of poor. Anyways, he thought it would make a good test part so he went ahead and made a casting from it! He used a really large opening so that he could easily see inside the investment when he burned out the PLA prior to pouring the metal.

So, without further ado, here is a pic of the part cast in yellow brass:


With the exception of the eyeball and the shoulder, all of the sloppiness in the metal part is real and was part of the original printed part. As I mentioned, it was a quick experiment. He believes the two metal blobs are air bubbles in the mold because he didn't pull bubbles out of the investment slurry prior to pouring.

For your amusement, here are the pictures he sent me when he first made it:

"OH NO! PLEASE DON'T DROP ME IN THE FIERY FURNACE!"



I survived. I AM IRON MAN!

 

I t seems the last two images links are broken maybe it is just me

 

What are the materials you plan to work with
and what precision do you think you can get out of it

 

OK. Try it now. I had copied and pasted it in before which must not work right. I got a kick out of it when he sent me the pics.

I can't seem to find the full list of materials we had discussed, but a pretty wide range of metals. Lower temp materials like aluminum and bronze up to higher temp materials liked brass. We're hoping to do cast iron as well, but we'll see. Any metals that melt below about 1300C will probably be fair game as a special request.

By precision, do you mean accuracy? You get some shrinkage from the casting process that will need to be accounted for in the model, but other than that, it should be an exact replica of whatever model is actually printed.

 

they work now thanks for the info it opens lots of potential doors

 

Pricing is TBD.
I'm sure I'm completely jumping the gun by posting anything here. At the very least we'll be cost competitive to 3D printed metals or 3D printed lost wax castings. Probably significantly cheaper.

 

DavidF is the 'local foundry guy' I mentioned in the initial post. Welcome to the group DavidF!

 

Hey David Welcome