What makes a good dry ice pot?

[Freddie123]

SO, I might be looking at making a ghetto dry ice pot. My idea was to grab a 2" diameter copper tube, and putting an end cap on it.

Then I was thinking of drilling a 1 1/2" hole in the end cap and inserting a 3cm long piece of 1 1/2" round copper bar in the end leaving about 5mm poking out. Does this sound ok?

[BeardyMan]

To answer you title question,

A solid one :)

To answer you post..

could you make a drawing?

[Stapler]

For dry ice it really doesn't take a whole low, any solid container will do pretty well, though obviously some will do better than others.

[Freddie123]

Like I said its ghetto, I also don't have any access to tools of any sort so it needs to be 2 piece :P I hear lots of mass is good aswell.

http://img101.imageshack.us/img101/6260/potsq1.png

The bottom of the round bar would sit on the CPU.

[Solarfall]

To answer you title question,

A solid one :)

To answer you post..

could you make a drawing?

yes but why are solid containers better.. can some one explain this ?? and how much better they are in terms of temperatures ??

[Stapler]

They're more massive so they can hold load better. The issue isn't so much temperature as staying power. I can hold temps within a degree or two through 32m runs on my Mousepot, that's pretty good. Of course you have to crush up the dry ice into snow and mix it well to hold that kind of load. Also their is often more internal surface area available to dissipate the heat as it's all one solid piece.

[Solarfall]

alright thanks Stapler for the insight.. it makes perfect sense :)

[ilkkahy]

The whole container doesnt have to be solid but bottom piece should be made from single piece and container has to be made out of copper. Aluminium may work ok with ln2 but dryice performance is always bad.

With good brazed container you can get same temps as with bad solid copper container. Here is picture out of three containers and below is the temp it gave under the 160w bench ive been using to test these. Left is solid copper container with bit too thick base (15mm), middle is basic brazed copper container with 12mm bottom where is some grooves for surface area, and on the right there is brazed container with 12mm copper poles that go trough the base:

http://koti.mbnet.fi/ilkkahy/dryice%20containers.JPG

Best aluminium container in that bench was identical copy of Sampsas solid cpu container and it gave -17c temps. Another solid aluminium cpu container in the bench ive tested was Waus-tube which gave only -7c.

I will make thread of the past test results in couple of weeks.

[Solarfall]

ilkkahy when you made that container that has those 5 poles, did you tested it with ln2 back then or only with dry ice??.. i'm asking this cos i have it, bought it from Mr. korhonen (SF3D)... still works very well btw. i only had to make a new mounting kit for it.. the previous one was... well lets put it this way very ghetto. :D

[ilkkahy]

I havent done any ln2 tests but im 99% sure itll work fine (unless it starts leaking in -190c temps which has happened to couple of my brazed containers). If mounting works its good enough for me.. I have made just prototypes instead of real finished products :)

[Solarfall]

I havent done any ln2 tests but im 99% sure itll work fine (unless it starts leaking in -190c temps which has happened to couple of my brazed containers). If mounting works its good enough for me.. I have made just prototypes instead of real finished products :)

ok good to hear cos thats why i was asking, it would really suck if the container would start to leak during a ln2 run.. i doubt it will happen though the brazing you did looks just fine to me.. all tough im no brazing pro. :D

[@rne]

I made the experience that Alu is ok for Dry ice . I had a pot from Otternase with Copperbottom and tube of Alu. The Load temp was about ~ -45°C with Celeron 335 (Prescott):)

[BeardyMan]

Well spreaded mass seems to be the key :)

[ilkkahy]

I made the experience that Alu is ok for Dry ice . I had a pot from Otternase with Copperbottom and tube of Alu. The Load temp was about ~ -45°C with Celeron 335 (Prescott):)

Yes but thats actually a copper container the because bottom was made out of copper. Tube part is pretty useless after, lets say 5cm distance from cpu. With copper/alu "hybrid" containers aluminium could be changed to plastic and the performance would not change at all.

Making bottom out of aluminum gives bad load temps with dryice. Computer setup is just not very objective method to measure container performance since there are too many changing attributes which can go wrong. Dummy load is. Im also under impression that almost any piece of crap container gives nice bios temps but thats just understandable if there is no heatload..

[Freddie123]

Thanks for your insights ilkkahy. If I get a pot made i'll get a solid copper base and then an alu tube.

[Stapler]

Semi solids are really popular right now thanks to Vince, but don't forget that he moved back to a full solid pot for the F1.

[Freddie123]

He also has lots of money to spend on outrageously priced copper ;P

[Stapler]

I'm just saying semi solid will get you 95% there, but to get that extra 5% you need solid.

[Freddie123]

True thanks for your input. Also how do you thread a pot? Like Kayls/LD's/Dunieks?

[Gautam]

Stapler, you aren't fully accurate there. A properly designed "semi solid" could offer more capacity than any container currently on the market.

Have you considered what "semi solid" means btw? Suppose you took the alu extension off the Evo, would that make it a solid or a semi solid? :p:

[dinos22]

Stapler, you aren't fully accurate there. A properly designed "semi solid" could offer more capacity than any container currently on the market.

Have you considered what "semi solid" means btw? Suppose you took the alu extension off the Evo, would that make it a solid or a semi solid? :p:

strokes my new pot :D

I WOULD STILL LOVE TO HEAR WHAT Newbeetle-san has to say on topic of DICE/LN2 vs different CPUs......he has some amazing experience and we are all looking very foolish commenting on what's good against someone with that sort of experience and results


new "bullet"
the biggest pot which I built yet :woot:
70mm tall and 64mm diameter
http://img170.imageshack.us/img170/4230/84549205eq4.jpg
http://img123.imageshack.us/img123/460/61433884jk1.jpg
http://img123.imageshack.us/img123/6200/98345521wh2.jpg
http://img123.imageshack.us/img123/6356/76899938vg7.jpg
http://img527.imageshack.us/img527/6223/mobo1ee5.jpg

sorry for quality :(

[Stapler]

Newbeetle has experience with different pots, but they were almost all made by Tam, I'd rather here directly from him. Still I trust Jason and Vince have a pretty good idea what they're doing. I mean Elmor pretty much always benches his chips over 2v and he's had great experiences with the rev 3. Same with Kinc, he usually benches with those kind of voltages and three mousepots. KP pushes his pots just as hard and I don't think there's any doubt about how they perform.

I haven't seen results of real heavy loads from Ilkahy's pots, but he seems to test them pretty thoroughly and I'm sure they're similiar quality.

[blind_ripper]

stepper_cone_centerpole base pots are no guarantee on succes.

[ilkkahy]

Newbeetle has experience with different pots, but they were almost all made by Tam, I'd rather here directly from him. Still I trust Jason and Vince have a pretty good idea what they're doing. I mean Elmor pretty much always benches his chips over 2v and he's had great experiences with the rev 3. Same with Kinc, he usually benches with those kind of voltages and three mousepots. KP pushes his pots just as hard and I don't think there's any doubt about how they perform.

I would not mix ln2 to this topic since we are talking about DRYICE containers. I havent seen any real container comparisons (load temps of different containers with exactly same setup) from any of these guys even though they are superior overclockers. But for example SF3D had very nice results under ln2 with aluminium Waus-tube which turned out to be piece of junk with dryice in my tester (-7c) which tells a lot how much good cpu chip may give wrong impressions.

I think temps under 160w load should reflect to heavier loads too (same c/w things apply here as with waterblocks and aircoolers) Contact surface area on my bench is quite small so it gives merciless results to bad performing containers like aluminium ones (you might get some kind of performance with pure aluminium though?).

Im not a big fan of cone/stepper type bottoms with dryice containers. It might be good with controlling ln2 temps though.

[Freddie123]

Still... how do you thread a pot?? :P

[ilkkahy]

Its made by lathe with certain kind of blade and automatic feed (or whatever its called in english).