LN2 Evaporator Design and Reference Links

[nzaneb]

I actually designed a 4" copper pot today, as to cut down on initial material cost and get away from the really long tooling required for the 6" pot. So you could essentially create an extension out of whatever you wanted.

 

[m0r7if3r]

you could always just use the styrofoam cup method...helps keep the ln2 usage down a bit too oddly enough. I think it keeps cold air in the pot and helps keep the pot cold? Idk, just something I noticed at the party.

 

[Bobnova]

Plastic cracks, that's the main lesson of the Koolance V1 and the Koolance GPU pot on high power cards.

 

[Captain Slug]

I haven't been here in ages, but I would just like to add that my responsibilities and expertise at my workplace now include both CAD work andusing MasterCam X4 to generate G-Code for CNC Milling operations on a Haas VF4 (with an indexer and probe).
We also have CNC Lathe equipment (Haas SL-20), but I don't have any practice generating G-code for that yet.

I have practice with 2D surface milling, 3D surface milling, 4-axis helical milling, and indexed 3D surface milling.


I don't have practice with setup or fixturing, but our full-time machinist would be willing to either get my code setup, or teach me what I need to know in that department so I can run operations on my own in the future.

Once you have a design picked and a mechanical drawing provided I can remodel it and use it to generate code, and a working prototype if material is provided.
I don't think I would be able to offer production services, but at the very least I could provide a full set of operation-ready files that you could take to any machine shop with CNC equipment. I can also advise on the most cost-effective production approach.

A 2-part design is highly preferable from the standpoint of fixturing end mills. Either the two parts could be thread mated, or you could interference-fit them together with a 20 to 50-ton press. Our highest rated press at work is an instrumented 55-ton, which could easily be used to mate a brass, copper, or aluminum tube to a base with a dimensionally matched round edge.


And as an aside, it is possible to TIG weld brass to copper using silicon-bronze filler rod. The welds have to be somewhat large and the welding process is a little fizzly, but the welds are solid. So if you try an interference fit and it's not sealed enough, brass would be an option for the walls. There's no big difference in price between the two right now though.

 

[ChanceCoats123]

Wow, very nice. And a great offer too! Thanks a bunch!

 

[I.M.O.G.]

Thanks slug, and damn good to see you brother. That old custom plexi LCD you sold me died a few years back, but I still think back to it every so often with fond memories - was a beauty. Glad to hear you are doing well professionally, and really appreciate the offer. I'll keep it in mind in case it proves beneficial once I'm ready to roll with this thing. If you have a chance, send me your preferred contact info - otherwise I'll send mail to your forum registered email and hopefully thats an account you still monitor regularly.

 

[El<(')>Maxi]

No need for welding a 2 part unit, press fit works fine. You don't even need a press, a very common use for LN2 is fitting precision bearings. You can freeze one part to shrink it and heat the other, with the right tolerances they will fall together...and when equalized never come apart. I like the threaded approach here - allows you to pull the unit apart when you need to adjust the base (drill more/deeper holes). Some of the tolerance fit pots make some strange noises under temperature transitions ── big cracking noises ── I don't think threaded units do that.

 

[ChanceCoats123]

No need for welding a 2 part unit, press fit works fine. You don't even need a press, a very common use for LN2 is fitting precision bearings. You can freeze one part to shrink it and heat the other, with the right tolerances they will fall together...and when equalized never come apart. I like the threaded approach here - allows you to pull the unit apart when you need to adjust the base (drill more/deeper holes). Some of the tolerance fit pots make some strange noises under temperature transitions ── big cracking noises ── I don't think threaded units do that.

So you're a vote for a round pot then since you like the threads. That should make milling, or lack of (lathing) a bit easier then.

 

[cold.nut]

keep going with this! i'm excited to see the final product