CXA3590 Build Plan

Sxott

Well-Known Member
Your tig welder needs to be for aluminum. It uses AC and its trickier to weld than reg steel with DC. I was going to use flat bar on the bottom of a square tube but the TIM between the 2 parts would create a big bottleneck for the heat and adds cost to the build. I'd weld fittings and end caps on the square tube instead and eliminate the heat having to go through 2 pieces.
 

reasonevangelist

Well-Known Member
You know these guys are helping me. They wouldn't let me make a mistake.

And really it is so easy. I just need to get them ready and follow the instruction. What could possibly go wrong?

1 - put the COBs on the drivers with the thermal interface compound

DONE!!!

...these black wire looking things...are what? Oh! Do I have take them out of the package?
View attachment 3389645
I always worry that 'somehow' the TIM by itself will fail to maintain contact when heated. Probably has something to do with the tactile smoothness of the compound when applied (which 'sets' after exposure to enough heat). I also worry, even when using fasteners, that, somehow, the TIM will flow and thin when heated, thereby reducing the previously attained fastener torque, thereby reducing the pressure keeping the thing affixed to the sink... and then, that, somehow, it will 'fall off' and potentially break the circuit while i'm not available to immediately intervene, should a breach occur. I wouldn't want anything arcing due to a failed TIM dropping an emitter and popping a wire, causing a potential high voltage arc, and all the scary stuff included in that scenario.

So i went overboard with kapton tape the first time, which worked very well. And my cobs did indeed slide a bit after they heated... but thanks to my McGyver taping, it was only like 1mm away from where it started. It didn't want to stick to the aluminum very well at first, but after a solid first run, i wasn't worried anymore. (but then i totally popped a weak solder on one of the points while moving it around one day, had to take it down and fix it... but no issues after that)

But yeah, i can confirm (as others have) that TIM is enough to keep it attached to the sink, as long as your wire tension isn't pulling it away... as long as you get a near-perfect spread (thinnest possible amount required for full mating surface coverage). Too little and it'll come off; too much and it'll slide more, and maybe even drip into something it shouldn't.

The problem is one I anticipated. It is a design choice to go with square tube. Round is so much easier to make connections, of course.

i drew up the tangents for flattening a spot on an aluminum round pipe. But, to get a 35mm square, flat cut makes the pipe awfully thin in the middle of the cut or awfully large in diameter.
And it is a lot of material to remove.

Really the best idea I may tackle later, is to create (or buy) small aluminum saddles that bolt onto a water pipe anywhere I want. Those bolts can also attach the drivers on the top of the pipe.

It is just much more fabrication than I can manage right now. But, not too difficult and certainly the most modular approach.

View attachment 3389962
^Nice.

Hmm... square rod, round bore? Probably also not exactly "easy."

Square Tube with closed ends, with threaded openings on each end?

Or... imagine having a tube of enclosed heatsink fins, with water flowing through it. Like if you made the whole thing into a modular waterblock, fins and all. Look at how CPU water blocks are made; imagine doing that in the shape of a pipe, instead. Could maybe even do something like... braids of fanned-out copper wire, inside a water pipe, attached directly to the spot directly behind the emitter contact point. Just throwin' it out there. ^^
 

Doer

Well-Known Member
The holders will ship next week. So I will have all the electronic paths squared away, but no need to build that yet. I will solve the water path soon. There are so many ways to do It. But, I am looking for the most easy.

You can find threaded bung plugs for 2" OD sq. But as a structural wheel hub attachment they are made of steel. Using even stainless, there will be galvanic corrosion.

And I can get 3/4" short threaded nipples in Aluminum. So, after my fiddle fart fun, probably the best idea is to have a welder put on 1/2" thick end plates that I drill and tap for 3/4".
 
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Doer

Well-Known Member
When I made a still head for a buddy, I used 100% copper scrubbers inside a pipe for the condensation surface increase. Worked well.
 

Doer

Well-Known Member
About the TIM.

1- the mask I use is blue painters tape. That makes a very thin pad. But, consistent.

I see people on the web with the CPUs just dabbing on a 6 glop pattern and twisting it down. WRONG.

Then you see another article on failure and they show a cpu with a 6 glop pattern that smoked. Why? All that air among glop pattern and the fact that the rest is so thick the total impedance, include the air gaps is monstrous.

2 - the good stuff does not creep around....part of the good.

3 - I won't just toss a device down on a pad, every again. Even with a perfect stenciled pad, you can't forget about the other surface.

The back of the COB is not at all smooth. It can be buttered tightly with fresh TIM. Scrap it into the COB back. Watch it turn gray as the ceramic voids fill. Don't make two pads, just butter the COB and strike it off. That's what I did for Peliters.

4 - when I put the device down I think of it like a peanut butter and peanut butter sandwich. Each side is wet. And I want no air. So I start at the edge, and work the array down in a line of wet contact, one edge across to the opposite side.
 

Doer

Well-Known Member
Looks like my ears were wrong again.

All Apologies

I wish I was like you
Easily amused
Find my nest of salt
Everything is my fault
I'll take all the blame
Aqua sea foam shame
Sunburn with freeze burn
Choking on the ashes of her enemy

In the sun
In the sun I feel as one
In the sun
In the sun
Married, maried, maried!
Buried!
Yeah yeah yeah yeah

All in all is all we are
All in all is all we are
All in all is all we are
All in all is all we are
All in all is all we are

I fixed it and I like it even better. Thanks.
 

AquariusPanta

Well-Known Member
Looks like my ears were wrong again.

All Apologies

I wish I was like you
Easily amused
Find my nest of salt
Everything is my fault
I'll take all the blame
Aqua sea foam shame
Sunburn with freeze burn
Choking on the ashes of her enemy

In the sun
In the sun I feel as one
In the sun
In the sun
Married, maried, maried!
Buried!
Yeah yeah yeah yeah

All in all is all we are
All in all is all we are
All in all is all we are
All in all is all we are
All in all is all we are

I fixed it and I like it even better. Thanks.
Come to find out, he was known to do stuff like, you know, changing lyrics on the go or having lyrics that, for some reason, sounded like one line and were really another.

Also, in the Unplugged version, he uses 'All alone is all we are'.

Anyways..

(:
 

Doer

Well-Known Member
OK, I cheated per @heckler73 "to get the most high quality solution." :)

Turns out there is s guy, "no job too small."

And he has a guy. That guy is making up the end plates with holes and the first guy will weld them on for $35. The machinst wants $50 to drill. I will tap them.

Thanks, heck.

(from the hard head who listens)
 
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heckler73

Well-Known Member
OK, I cheated per @heckler73 "to get the most high quality solution." :)

Turns out there is s guy, "no job too small."

And he has a guy. That guy is making up the end plates with holes and the first guy will weld them on for $35. The machinst wants $50 to drill. I will tap them.

Thanks, heck.

(from the hard head who listens)
I can't wait to see it...Should look gorgeous. ;)
 
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