LN2 Evaporator Design and Reference Links

[ChanceCoats123]

I know. The article I linked to calls it, "This became known
as the British Standard Pipe thread (BSP Taper or BSP Parallel thread)."

 

[cold.nut]

gemini doesn't have any leaking issues. if you are worried about a square two piece pot, then just put some teflon tape between the base and the walls. if you really want to be sure that you have a tight seal, put some silicon putty or some vaseline between the base and walls and some teflon tape.

it works ! don't be too shy with square base ideas.. vince's pots are considered the "cream of the crop", he uses a square base.

choose between circular or square, then follow through with the design. i wouldn't worry too much about sealing; just follow the rules of common sense.

 

[m0r7if3r]

gemini doesn't have any leaking issues. if you are worried about a square two piece pot, then just put some teflon tape between the base and the walls. if you really want to be sure that you have a tight seal, put some silicon putty or some vaseline between the base and walls and some teflon tape.

I was in the livestream when miah's gemini was leaking, and ive heard of others' doing it, so at the very least it happens...

 

[cold.nut]

last i check though.. miah got an early prototype version. it is still retail, but the quarks hadn't been worked out by the time he got it.

so yes, the early gemini's had issues. vince fixed the issue though.

 

[ChanceCoats123]

Maybe a very slight taper could be used? As in a taper on the base, but straight cut on the top so that it seals itself when you tighten the top down.

 

[m0r7if3r]

would that not wear out over time? (<<<bad at threading outside of basics and personal experience)

 

[ChanceCoats123]

I honestly have no idea. I was just snowballing here.

 

[Bobnova]

A slight taper is likely to seize up when pressed together cold and allowed to warm.

Miahs gemini isn't the only one that leaks.

 

[moocow]

The Gemini I got my hands on didn't fit properly and I've heard of a few other instances where the heavy base isn't manufactured correctly and will leak.

 

[ChanceCoats123]

Good to know. Is anyone extremely against a circular pot?

 

[I.M.O.G.]

Not me, basically picked one because one needs picked, and a square is easier to cut around the socket insulation (trivial).

 

[Bobnova]

Round could be done with a lathe and a drill, square requires a mill (or a round hole in a square pot). That is, i think, why so many pots are round.

 

[nzaneb]

Slightly OT @ Splat

Have you had a chance to play with SW analysis any further?
​

 

[ChanceCoats123]

Round could be done with a lathe and a drill, square requires a mill (or a round hole in a square pot). That is, i think, why so many pots are round.

Not needing a full mill will make it easier, yes? Possibly a round copper bottom, using the parallel threads (for a seal) and then an Al top. Hell the top could even be Cu to avoid the contraction and expansion rate issues.

Then it could include either idea that has been recently discussed. Be it the steps from the side to the middle, with the four holes (most recent from Nzaneb) or the four holes stepping to the sides.

 

[m0r7if3r]

Thing is, if you do copper for the top then you've gotta get a solid chunk of copper that big anyways and you might as well just do it in one piece.

 

[ChanceCoats123]

The point was to make the milling/lathing of the base easier... not to reduce cost. (Two piece design, that is.)

Ps. I'm just guessing here, since I don't actually know, but could one buy copper "pipe"? Like a 2.5'' OD, with a 2'' ID?

 

[Khemikal]

The point was to make the milling/lathing of the base easier... not to reduce cost. (Two piece design, that is.)

Ps. I'm just guessing here, since I don't actually know, but could one buy copper "pipe"? Like a 2.5'' OD, with a 2'' ID?

Yes this can be done, but with limitations on what the retailer has to offer. MCMaster has a decent selection of things like this, so go check their stuff out to see if you can get close to what you want. I would be willing to bet if you can't find exactly what you wanted, but could find something close, that they would work with you on getting something made.

 

[I.M.O.G.]

Yes this can be done, but with limitations on what the retailer has to offer. MCMaster has a decent selection of things like this, so go check their stuff out to see if you can get close to what you want. I would be willing to bet if you can't find exactly what you wanted, but could find something close, that they would work with you on getting something made.

Small quality special order pipe would not be any cheaper than milling bar stock.

By the way, I've been staying tuned, but this is sort of on hold due to RL getting in the way. Can't spend money right now on LN2 or buying copper. Within a month or two we should be moving forward again with getting something milled off the designs that have been made. Hopefully splat or someone can come up with some FEA in the meantime.

 

[xsuperbgx]

I would think, if your mass and surface area on the base is enough you dont even need a copper tube. You could use some plastic pipe and a pipe thread maybe?

 

[m0r7if3r]

then you have to worry about leakage as the materials shrink differently (-196c is a BIIIIT chilly)