Lost PLA casting


#1

If you want to create things in metal, there are folks using PLA plastic to do investment casting. DavidF from the SeeMeCNC forum is (as far as I know) the expert on the matter. Check out his process, it’s pretty cool! http://forum.seemecnc.com/viewtopic.php?f=41&t=5986

There was also a recent King of Random episode about it (using styrofoam, though), and I also found this HackaDay article: http://hackaday.io/project/2434/logs

I don’t know if I can share any specifics or not, but another one of The MakerHive guys is even formulating an SLA resin for investment casting.

Has anybody here done any metal casting? From a 3D Printed part? Please share!


#2

I should also mention, there are some investment wax filaments on the horizon. I haven’t seen the report yet, but be on the lookout for DavidF’s experience on the matter.

http://forum.seemecnc.com/viewtopic.php?f=80&t=7637


#3

Holy Moly this looks almost too cool for me…

Nowadays you really cannot try everything on your own, so many people making awesome stuffs out there and you will never know if you don’t walk out…

Thanks for your sharing, Jim. So glad to learn another brilliant project.

  • Hunter.

#4

That’s what I’ve been looking for. I’ve done lost-wax silver casting, and even used plastic. I don’t know how much residual ash PLA leaves behind after burn-out, though. It’s a definite area to explore. You can even use bronze casting beads…


#5

Reclaim your own metals:
Grant Thompson/ The King of Random has made a few projects that may help with this.

He uses styrofoam but I think the process would be similar. - https://www.youtube.com/watch?v=tH-PaNugz9w

Make the metal foundry (Al can recycling) - https://www.youtube.com/watch?v=hHD10DjxM1g

Arc furnace (Zn or higher melting point metal recycling) - https://www.youtube.com/watch?v=VTzKIs19eZE


#6

Found someone that has already done some PLA casting


#7

Good info here. Recently I bought an injection molding machine and have been looking for ways to save on milling molds in metal. Have wondered about the lost-PLA method.


#8

Yeah I was just going to reply to you that I’ve read about wax filaments you can print with to do metal casting. It is a really cool subject to talk about. The 3DPrinting company Shapeways is actually offering a castable wax material they can print with. Although they have very expensive machines to do that for them.

Here is a link to that page: http://www.shapeways.com/materials/wax

Also I have read about people printing positive models of their objects from plastic. Then using casting silicone or other materials to make the negative. Finally using that negative to make the final product. Yeah I know, that is a very long & tedious process. But its what you have to do for now, until something better comes out. :slightly_smiling:


#9

There’s another product I’ve seen online that is wax filament for 3d printers. It looked like the cat’s pajamas until I saw forum activity that described a problem. The user was unable to reduce the temperature of the print head to encompass the correct range for the material.

That’s something to be determined for the Flux Delta, isn’t it?

machinable wax filament


#10

They other filament that you can look at is “MoldLay”, from the same people that make bricklay and several other specialty filaments.

Everything that I’ve seen, with a few exceptions, would be material that you make into a positive investment, encapsulate with layers of slurry and sand, and melt out before you cast your metal. The exceptions are people who’ve figured out clay extruders and a ceramic UV resin from Tethon that just ran a Kickstarter.


#11

I was doing research on this topic because I am making the mini metal foundry from Grant Thompson and have a Pla 3D printer (from XYZ). I haven seen anybody pour metal directly onto the plastic so I don’t know if it will work or not, but that’s what I will find out. I plan on posting my results here, since it is one of the first places I looked, and I hope more people will see my results and be educated. My concerns are that 1. The metal (I will most likely use aluminum) will not vaporize the pla and something bad will happen, and 2. The pla will have moisture trapped inside of it, since that is a trait of pla, and will ‘explode’ like concrete does when hot metal is poured on it. Hopefully, though, the metal will be hot enough and the results will be similar to if I was using a foam or wax positive buried in sand. I am hopeful since aluminum’s melting point is 660 degrees Celsius and pla’s melting point is 175 degrees Celsius. As I said, I will post my results here. I expect to be doing this within 2 weeks, but, depending on school and life, that may increase. I’ll be back, Skullngloves. (One thing I forgot to mention is that I will be using a low infill and shell density so there is less plastic. That, I believe, will give me the best results.


#12

Sounds interesting! Just make sure you’re behind something nice and solid (and preferably far, far away!) when that aluminium pours in just it case it does go off like a small bomb!


#13

I did some Googling, and it looks like you can use PLA with aluminum. The main thing this article suggests is using as little infill (and probably perimeter) settings as possible.


#14

Cool! Thanks for that article, I was wondering why nobody had done it before, but I guess I just didn’t look hard enough. And trust me, I’ll be safe. My dad has done lots of castings and we are both very careful when doing dangerous stuff. I might do a plaster mold, sand mold, or even both molds, so I’ll post my results here. Thanks, Skullngloves.


#15

Did you try it since this last post? I’m gathering the materials to build the same mini foundry and have been wanting to do this since I got the Delta 1 year ago.


#16

I have and it didn’t really work. It just melted the top and then the aluminum cooled too much. I’m going to try some other time but won’t be able to for a long time. (Until school starts)


#17

I’ve done lost-wax and lost-plastic casting of small objects for jewelry. You can even use dried insects! The best way to do that is to use jewelry investment (porous plaster) and use a kiln to burn out the wax / plastic model. You might be able to use a regular oven at 500 degrees, or maybe run it through a self-cleaning cycle to burn out the plastic. You might not want to coat your food oven with plastic fumes and smoke, though. After that, you can use a vacuum caster (you can get cheap ones) or a centrifugal caster to pull / force the molten metal into the cavity.
Here’s a youtube using the centrifugal method: https://www.youtube.com/watch?v=Aub_UpFereQ


#18

Which entry level vacuum setups are worth looking at?


#19

As you see from looking at Amazon, etc. there is quite a range of prices. Many of those vacuum machines, though, are mostly for pulling a vacuum on the liquid investment to get any bubbles out. That can be useful for intricate pieces, but not always necessary if you’re careful about painting your piece with investment beforehand. My own vacuum caster is a very simple setup with a manual suction piston. It’s for small pieces and is intended for jewelry. There’s one for sale (overpriced) on eBay:
https://www.ebay.com/i/173236598022?chn=ps
This one seems to be the simplest full vacuum setup, but you’d need to supply your own source of vacuum. http://www.grobetusa.com/vacuum-assist-table-item-no-21-806g/
The cheapest vacuum source is a water-faucet venturi that uses water flow to create a fairly good vacuum.
https://www.amazon.com/Deschem-Stainless-Aspirator-Humboldt-Aspirators/dp/B077CGL5JS/ref=pd_sbs_328_1?_encoding=UTF8&pd_rd_i=B077CGL5JS&pd_rd_r=CG801VQWM15JSFP8GD04&pd_rd_w=vkbKx&pd_rd_wg=Ctuvp&psc=1&refRID=CG801VQWM15JSFP8GD04