Liquid Nitrogen... for freezing... anyone have any thoughts?

[Code54]

Saw this last week here in my town - Not too often you see these storage tanks on craigslist

CHART MVE XC 33/22 Liquid Nitrogen sample storage tank large - electronics - by owner - sale

 

[Kyle_in_Tex]

I have a complete cold head system on ebay for sale. It comes with a nice 5 gallon dewar. Make your on LN.

Actually, we "hopped" it up to get even colder for a project and you can actually make solid oxygen (which is kind of dangerous).

So if you decide you need continuous amounts of LN, and have 3 phase power for the additional chiller system needed (included in sale), just look up cryomech cold head on ebay.

 

[Texasmark]

What about a hot wire to cut through it like is done with Styrofoam brand expanded poly......... blocks?

 

[GLyford]

What about a hot loop, rather than a straight wire? Sort of like the working end of a soldering gun. I know they use a handheld version for carving styrofoam.

 

[3Ts]

I know you said wax won't work, but it is used in investment casting. Why can't you used the same idea?
- use machinable wax
- use casting plaster for a mold to coat the wax
- heat the plaster so the wax runs out
- fill the mold with foam
The mold could be made in multiple parts if needed and even so the entire piece of wax could be lifted out. Reassemble the mold and pour the foam.

 

[Dadnatron]

3Ts... That might work. That is a lot of steps, but might be an option down the road should I fail at directly milling the foam.

I contacted the local 'Makerspace' locations. Unfortunately, they have very small beds, which wouldn't be an issue, but I don't think the collet will accept my bits nor is the head height adequate for my bits.

I'll keep looking, but that would have been the optimal option.

 

[IslandTractor]

Have you considered a layered build using many sheets of thin foam? You could cut each layer separately before assembly to achieve whatever shape you want then stack and glue them together.

 

[mapper]

Can you get the foam in liquid form that could be used in a 3D printer? The only modification needed might be the nozzle in the print head.

 

[Kyle_in_Tex]

Have you considered a layered build using many sheets of thin foam? You could cut each layer separately before assembly to achieve whatever shape you want then stack and glue them together.

Excellent idea IT. thin layers with some strategic holes to locate each layer when gluing up.

Just slice them up in cad. Easy peezy. Cheep laser cutter will cut each layer. Just need to find glue that is acceptable

 

[jimmysisson]

If I had foam all around my upper torso and back if my head I would sweat like a pig. Ventilation seems a must, though the techniques of building these is more interesting.
Jim