Any news on the cascade xxx?

[guandi]

This may be a long shot, but a few days ago i half watched a program about medical research that said something along the lines of metal needles for cell injection were too big, so they used high strength Glass ones. i heard something about glass being melted, and then suction formed into tube shaped down to "one millionth of an inch" ID.

I too want a Cascade, SS would be prefered but anythign will do :P

[Cathar]

Turns out the machinists were using acrylic, rather than polycarb. I explicitly asked for poly-carb, but they wanted to see if it would work with acrylic since they didn't have any suitable polycarb lying about.

8-ball, what was going on was that as the tubes were being machined down, the ends of the tubes would chip away, leaving a tubeless piece. This is exactly what I feared would happen if acrylic was used. Acrylic is quite a deal more brittle than polycarb and doesn't handle vibrational stresses that well. It'll just crack if you try to cut it too fine. The tubes have 0.20mm wall thickness while being cut, and the acrylic was just falling away as a result of the cutting action acting on so thin of a thickness.

The 0.20mm wall thickness is actually about the same that is on the current Cascade, for which the wall thickness varies between 0.20-0.30mm with the hexagonal shape of the tubes when being cut. They then get drilled out to around 0.10mm thickness at the thinnest bits, so I know that polycarb is capable of being machined to such levels.

The thing is now that they've been set back with the acrylic they are reluctant to re-try with polycarb. LOL - I always tell the machinists that it's my job to push them to levels that they never knew they could achieve, and the sales rep for the NC mill continues to be impressed at the levels being pushed, so I find myself (again) in the situation of trying to convince them that they can do it. They'll come around with a bit of pursuading. I seem to go through this with them every time I ask for something new.

[|kbn|]

Im interested whats the ID of the jets? 0.10mm wall thichness, you must have a lot of jets on this one then!
I havent used polycarb yet but polyethelene would seem to be a lot less brittle and wont crack when drilled/overtigtened/machined, dunno how well it would work so with holes so small though. The stuff I have is translucent though and clear would be best for blocks...

[Cathar]

Originally Posted by |kbn|

Im interested whats the ID of the jets? 0.10mm wall thichness, you must have a lot of jets on this one then!

149 jets

Yeah - I'd consider polyeth if needed. It doesn't have to be clear, so long as it works. The polycarb is very resilient though. You can grab a jet tube on the Cascade, fold it sideways completely, and then bend it back, and it won't have snapped, and will mostly retain its shape. Do that to acrylic and it'll snap as soon as you apply sideways pressure to it.

[kronchev]

just wondering, but why hasnt any of the major block makers picked up your design yet? or have you not let it go? large scale manufacturing would be great, I would actually get one

[pauldenton]

Originally Posted by Cathar

The thing is now that they've been set back with the acrylic they are reluctant to re-try with polycarb. LOL - I always tell the machinists that it's my job to push them to levels that they never knew they could achieve, and the sales rep for the NC mill continues to be impressed at the levels being pushed, so I find myself (again) in the situation of trying to convince them that they can do it. They'll come around with a bit of pursuading. I seem to go through this with them every time I ask for something new.

if it'd help, i'm sure we could promise a lot of work....

[kaotic504]

how much is a regular cascade?

[|kbn|]

I didnt know polycarb was that good!

[bigben2k]

It's just expensive to make.

Consider the price of a DTek WhiteWater, and compare it to the price of a Cascade: :o

[Cathar]

It's the machine time that's the issue. There's about 1 hr of CNC machine time in each block, and a further 30 minutes of manual labor.

[Blackeagle]

Hi Cathar,

I posted a e-mail to you a while back regarding the SS Cascade. Any progress toward having enough people for another batch to be worth your time?

Thanks man, You do great work!

[Cathar]

Woohoo!!

Just off the phone to the machinists. They successfully cut the middle plate in polycarbonate on the CNC. They warned that it is a little rough due to the cutter being used being somewhat blunt, but overall the operation was a success. Apparantly a couple of the tubes have split on the edges, but this was more due to a small programming fault that they're now aware of and will fix. Such is the way with first-run prototypes.

Anyway they'll be machining up the copper plate tomorrow or the day after and by this weekend I'll have the first working XXX prototype (in copper) to play with.

[UberBlue]

That's definitely good news!

Looking forward to pics.

[kaotic504]

nice, i can't wait to see it.

[Cathar]

Originally Posted by UberBlue

That's definitely good news!

Looking forward to pics.

More looking forward to performance myself. I already predict that at low flow rates that it'll put the regular Cascade to shame, since that was one of my goals when designing it. Let's say I've been influenced too much by people putting heavy weight in foreign tests run at <2LPM. The XXX should continue to offer the same rough rate of performance gain as flow rate is increased as the regular Cascade. Perhaps more, perhaps less. I don't know. Depends on which variable is the dominant factor in reality as opposed to theory. Maybe hoping for a 1C gain over the Cascade.

Really though, and what was the focus of the block's design, was to pay more careful attention to smoothing out hot-spots. This is something that I can't really measure except in terms of overclock stability. An improved overclock will be the true measure of success for the XXX for me, and not so much the actual temperatures seen.

So more focus on jet/cup geometry interaction, inter-cup geometry, and matching that off against the base-plate thickness. Am very excited.

[BillA]

measured temps are NOT the measure, chase the (CPU to CPU variable) overclock, better resolution
yes, FAR more work but more significant results
(glad its Cathar's time and not mine)

? how can you 'SMOOTH' a hot spot whose location is not known ?

[Cathar]

Originally Posted by unregistered

measured temps are NOT the measure, chase the (CPU to CPU variable) overclock, better resolution
yes, FAR more work but more significant results
(glad its Cathar's time and not mine)

? how can you 'SMOOTH' a hot spot whose location is not known ?

Will have 3 separate CPU's to play with. Yes - a lot of time.

Regarding "smoothing", apart from location - also the size?

Really what I'm attempting here is a prediction of the lateral heat-spread though the bp given the assumption that the cooling is not going to be equal across the base of a cup/wall "cell". So assuming an infinitessimal point - it's a case of figuring out what amount of material needs to be between the CPU and the convection area to ensure that effectively an entire cooling "cell" is engaged for a point source of heat, but also not putting so much material in the way that conduction becomes a major cost.

On the original Cascade I could only say that really about 1/3rd of any particular cooling cell was acting on any given point of heat. In fact the size of the cooling cells made it somewhat hard to set the bp thickness at an acceptable level without the cost of copper conduction becoming a major concern.

In essense the 25% shrink (in each dimension) of the XXX was absolutely necessary to provide a better tradeoff between lateral heat spread and conduction. Ideally I'd like the XXX to undergo a further 20% shrink to get it all "perfect", but that's a battle for another day.

Overall in the XXX the net conductive thermal resistance hasn't dramatically changed from the regular Cascade, just better balanced, or "smoother", as I put it. Am hoping for tweaks to the jet geometry/velocity to buy some overall performance gain, but again, not exactly holding out really high hopes.

Of course the savvy of you will have worked out by now that the XXX has a thicker base-plate than the Cascade, and that does directly translate into better low-flow performance. Incidentally the SS has a 40% thicker bp than the regular Cascade. The only real doubt in my mind is how the thicker bp affects higher-flow performance. Will the copper conduction cost become the dominant factor within the limits of the flow rates that I'm capable of enacting on the block? This is the question that I have really yet to wholly figure out.

[OneMadPoptart]

That's great Cathar! I hope the rest of the machining goes well.

As a physicist, I too am interested in the temperature results regarding the change in baseplate thickness and other factors you have mentioned. Testing should have some interesting results I'm sure.

-OMP

[BillA]

Cathar
you are aware of EK's testing, some of which yielded a higher OC with a higher CPU temp ?

you realize that with a resistor network you can model your bp ?
then you can back-calculate to get a fit for the different bps
but then you will need to address the thermal lag (capacitance) which affects the OC
gets too hairy for me when it is then necessary to characterize the magnitude and duration of the thermal transients

[jlrii]

Hmmm....the next step in the Cascades evolution? Where to go from here? This stuff supposedly boasts a rating of up to 1200 W/m*K. If it's all they say it is I imagine lateral heat spread would improve quite a bit. Not easily machinable tho'. Here is a responce from them regarding a few questions I had.

"Knoop Hardness is around 60 GPa, depending on DiaCu-II formula used. Lower diamond volume percentage DiaCu-II versions can be machined with wire-EDM, however, normally DiaCu-II must be laser-cut. Typically we provide machining and metallization services for our customers. DiaCu-II is not permeable to water; as far as creating a water seal, our current samples are shipped with a minimum 0.25mm layer of O-Free Cu on both flat sides of the DiaCu-II disks – so, assume that a seal would be created against the desired finish of the copper or any external plating/sputtering on top of the copper. Factory finish is fine-lathed OFHC copper surface, but can be mirror polished if desired (Cu is fairly easy to lap for most any customer). 90mm slugs will be available by Q2’04, depending on demand."

I did not get a quote so pricing is up in the air. It'd be fun to play with though.