Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

Water Cooling

Gina

By Gina
in DIY Astronomer

Recommended Posts

Gina

Gina

Posted
  • Author
Posted

Here is a quote from one of the eBay sellers for the exact same model (Zalman ZM-WB5 Plus)

It is a beautifully designed CPU water block and has a pure mirror-smooth copper base for best heat transfer.
So why is mine like chromium plate and not mirror flat? I'm baffled!
Link to comment
Share on other sites
  • Replies 144
  • Created
  • Last Reply
Gina

Gina

Posted
  • Author
Posted

Well, it might be but it's still not flat. I guess a decent thermal paste should fix that but the item is not as described.

I've been searching again for water blocks. There's a north bridge block at a higher price. It's 37mm square so an uncooled border of 1.5mm. I would say the innards are at least 1mm inside the ceramic plates (or whatever it is). It's lighter than the Zalman CPU block. OTOH I don't feel like spending yet more money - maybe I should have gone for the Corsair H40 I was thinking of originally but I've no idea how heavy the CPU block is. Some separate blocks are 300g.

I think I'm going back to making my own TEC hot side water block. Either a spiral of copper tube or maybe an air cooler boxed in to make a water cooler - lots of surface area for heat transfer.

Decisions, decisions :)

Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted
Actually, couldn't you use (at least some of) the excess heat for a dew heater? Just run the hose around the objective lens a few times before it goes back to the radiator...
Yes, that's a good idea :) It would be easy to run the pipe a few times round the scope.

I don't think I can be bothered to return the Zalman water block - I'll use it for the water cooling heat exchanger fitted to a standard CPU cooler/fan. I already have a pump ordered and I'm thinking of making my own hot side TEC heat exchanger. I could make something quite light I think.

As well as the 12v 50W 40mm square Peltier TEC I also have a 5v 20W 25mm square one. I think I'll try the 5v one and see how that works. Another thought is piggy backing the 5v and 12v TECs to provide a larger temperature drop. Both are rated at the same current so I could put them in series electrically.

Link to comment
Share on other sites
Auntystatic

Auntystatic

Posted
Posted

Gina you are a blumming inspiration to us mere mortals, I watch all your mods with great interest, and keep changing my own plans according to your many successes and occasional failure :)

Maybe I should have put this in a PM but I know others will feel this way too.

:):headbang::(:p;):hello2::D:hello2::):):icon_salut::):icon_salut:

Link to comment
Share on other sites
Mr TamiyaCowboy

Mr TamiyaCowboy

Posted
Posted

a 80cm to 120 cm rad and fan will keep a Tec fairly cool.

have a look at a GPU block they are slightly smaller footprint of the cpu blocks.

pumps used tend to be aquarium type and a flow meter in the pipe chain shows you the flow speed and when everything is working.

thing to remember is they weigh a fair bit. you have a pump unit, pipes, res, rad,

using a heatsink with thinner vanes and a hi flow fan would be better and cheaper. mounting the fan can be done using rubber gromet style pull trough cones and take away the vibration nearly. using a good thermal paste is also key. something like arctic silver spread with a plastic slither/card and then married to the TEC plate. better than straight metal to metal. the paste gives a good thermal transfer

Danger den maze4 is a good low profile water block would look good in a TEC mod and the low profile handy.

Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted

The pump came today. It doesn't have an inlet connection but is intended to be submerged in water so I'll probably put it inside the reservoir and connect the return pipe to that. While out this morning at the farm shop I managed to pick up a couple of metres of about 6mm bore soft neoprene tubing - very flexible and just the job for the connections to the heat exchanger on the TEC hot side.

If the pump proves awkward I'll have a rethink. Might even look into making my own pump. One thought is a peristaltic pump - no problem with possible leaks.

Oh, and I attached the Zalman block to my 80mm heatsink earlier using some of the fixings provided - looks good :D

Link to comment
Share on other sites
JamesF

JamesF

Posted
Posted
Actually, couldn't you use (at least some of) the excess heat for a dew heater? Just run the hose around the objective lens a few times before it goes back to the radiator...

I love that idea. Burning electricity just to turn it into heat always seems so wasteful. Using waste heat from something else appeals to me much more.

James

Link to comment
Share on other sites
yesyes

yesyes

Posted
Posted

That's what I thought... on one hand you use energy to cool something down (which has already used energy to heat it up) and on the other hand you again use energy to heat the dew heater... seems too wasteful.

Link to comment
Share on other sites
JamesF

JamesF

Posted
Posted
If the pump proves awkward I'll have a rethink. Might even look into making my own pump. One thought is a peristaltic pump - no problem with possible leaks.

A peristaltic pump shouldn't be too hard to build, I'd have thought. Unless one comes up for cheap on that ebay.

James

Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted
A peristaltic pump shouldn't be too hard to build, I'd have thought. Unless one comes up for cheap on that ebay.

James

That's what I thought. Looked on ebay - nothing cheap enough.
Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted
might be able to salvage one from an old inkjet printer (the print head cleaning pump). But most likely the flow rate would be too low.....
Yes, I think it would be...
Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted

The sensor is attached to the image processing board with about a millimetre gap between. This is the only space available for cooling and therefore a cold finger is the only option for direct cooling. See my cold finger cooling thread for more details.

Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted

I have an initial idea of how I might arrange all the elements of the cold finger cooling system. I've checked the pump and the head it will drive is about a foot so it would want to be at much the same height as the reservoir. In fact being a submersible type it makes sense to have it in the reservoir. The return can simply go in the top of the reservoir. I'm thinking the reservoir could be placed on top of the mount and the air cooler too. The hot flow can go from the Peltier TEC water block up the side of the scope, into some copper tube wrapped round the objective lens position just below the dew shield then back to flexible tube to the water block on the cooler. Here is a drawing of how I see this arrangement.

post-25795-133877762952_thumb.png

Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted

Here's a more refined diagram of the cooling system. The reservoir containing the circulating pump is mounted on a piece of wood which is attached to the mount using the polar scope viewing hole. Also mounted on the wood is the water cooling unit consisting of the Zalman water block, heatsink and fan. Copper tube is used to shed some surplus heat to provide a dew heater. The cold finger at the side of the camera has Peltier TEC and a small home-made water block connected by very flexible tubing to the copper tube and the pump. Allowance will be made for moving the camera further away from the scope for a Barlow and also for the rotating joint between scope and mount. Flexible plastic tube provides these functions.

Using a fairly tall reservoir (table sweetener plastic jar) allows for the tilt of the mount and by mounting the whole assembly on the mount polar axis means that the tilt is never enough to spill the water - it just tilts in different directions while remaining just 39 degrees off vertical. This arrangement keeps piping short and free of the rotation of the mount on it's axis - only cables cross this junction.

post-25795-133877763089_thumb.png

Link to comment
Share on other sites
Gina

Gina

Posted
  • Author
Posted
You might want to make sure the bottle is full up with no air bubbles and water tight, as when your mount slews the bottle might lie on its side.
The reservoir bottle will never be more than 39 degrees from vertical (90-51 the latitude here). The bottle will be mounted on top of the RA part of the mount. This rotates on the polar axis so the bottle will always point towards the celestial pole - 51 degrees from horizontal = 39 degrees from vertical.
Link to comment
Share on other sites
Mr TamiyaCowboy

Mr TamiyaCowboy

Posted
Posted

maybe swap the heatsink and head unit for a radiator.

a 8cm radiator with the 8cm fan will be a better cooling solution,

tec heat to header block, headerblock to dew.

dew to radiator then res.

search ebay for CPU water cooling radiator. seen a couple 120cm rads on there for a tenner. that would be ideal as an exchanger.

smaller 80cm in ebay is Item number: 290696160417. this one is smaller than the 120 and more handy size

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.