More lost pla

[DavidF]

print burn cast, print burn cast, seems like all I ever do any more. But I must say I have gotten most of the bugs work out of the process now..

[img]http://i1102.photobucket.com/albums/g446/davidflowers1/utf-8BSU1BRzA3NDYuanBn.jpg[/img]

Printed part on left and cast on right

[mhackney]

Very cool David! I'd say you have it down. What temps are required to burnout PLA?

[DavidF]

Very cool David! I'd say you have it down. What temps are required to burnout PLA?

I start with the kiln pre heated to 260C and ramp up temps 200C every 2 hours until I reach 730C then I hold for 2 hours. I then back the heat down to pouring temp (usually 260C) but sometimes hotter depending on how thin the castings are. Judging by the smell I would have to say that the PLA is buring out at 500C
but the temps must be driven higher to burn out the investment. Its not the part you are really burning out, its burning out the investment.
I also use vaccum assist when I pour which does wonders for the finish. Now if I can get on the droplit beta test....well you can see me cnc where im going LOL

[DavidF]

[img]http://i1102.photobucket.com/albums/g446/davidflowers1/Mobile%20Uploads/utf-8BSU1BRzA2NzQuanBn.jpg[/img]
[img]http://i1102.photobucket.com/albums/g446/davidflowers1/Mobile%20Uploads/utf-8BSU1BRzA2NzcuanBn.jpg[/img]

[Jimustanguitar]

Thanks for sharing your process, that's great!

[Eric]

What do you mean by vacuum assist in this case?

I've never tried lost investment, but I did some split-mold casting years ago.

[Jimustanguitar]

What do you mean by vacuum assist in this case?

https://www.youtube.com/watch?v=tEJwKhiRIUs

[DavidF]

Once the investment is burned out it becomes porous enough to allow air to pass thru it.
Vaccum is drawn around the outside of a perforated flask and the molten metal is basically sucked into the mold.

[McSlappy]

This is awesome!

[teoman]

Out of curiosity. What is the cost of such a diy setup?

[DavidF]

Out of curiosity. What is the cost of such a diy setup?

Difficult question to answer. I have been into metal casting for 7 years or more and have been building and upgrading for that length of time as well.
to thow a dollar figure out i would say i have between 2-3K invested in it so far.

[teoman]

It will not be possible in an appartment I suppose...

What about if I acquire some friends that are in to ceramics.

[DavidF]

It will not be possible in an appartment I suppose...

What about if I acquire some friends that are in to ceramics.

you could get an electric furnace and kiln, but the burning pla Stinks up a city block.

[1ggy]

If you're just doing metal, it's not too difficult if you're willing to go with the bare minimum. I built a small furnace on the back porch of my high school art studio, which consisted of an igloo of firebricks, a blower, and a propane burner. We melted aluminum in a large soup can and the plaster molds were kept at the entrance of the furnace to keep them warm before pouring. You're not gonna get castings of the same high quality without the vacuum flask and fancier equipment, but it can be done on the cheap with fairly good results.

[DocHogan]

It will not be possible in an appartment I suppose...

What about if I acquire some friends that are in to ceramics.

Small electric kilns for apartment balconies are not at all uncommon No idea how suitable for investment molds they are, but...

[teoman]

Propane based stuff does seem to be simpler...

Building a setup at school seems to be a good idea. Lots of space. I could probably set something up at my uni.