Water cooling system tanks

I'm planning the cooling system for my 6040 CNC (800W water cooled spindle) and am not 100% sure on what I need.


When I look at other CNC builds, they all seem to have huge reservoir/tanks. Far larger than I am able to find on any PC parts place.


I understand that if you don't want to put a radiator and fans then of course you will need a larger amount of water. However, if I use a single radiator and single fan, is there a rule of thumb about how much liquid coolant I will need then?


Also, any tips for a place that sells larger tanks? Are people making their own out of acrylic and glue? Is that a viable option?

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Originally Posted by d4cnc

I'm planning the cooling system for my 6040 CNC (800W water cooled spindle) and am not 100% sure on what I need.


When I look at other CNC builds, they all seem to have huge reservoir/tanks. Far larger than I am able to find on any PC parts place.


I understand that if you don't want to put a radiator and fans then of course you will need a larger amount of water. However, if I use a single radiator and single fan, is there a rule of thumb about how much liquid coolant I will need then?


Also, any tips for a place that sells larger tanks? Are people making their own out of acrylic and glue? Is that a viable option?

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If you are using a small radiator like I do then 1 ltr of water will be enough. I ran mine for ages without a radiator and just 5 ltrs of water with no problems you will need a very small pump as well. As for the tank a Tupperware container will do.

I've just got a small aquarium pump (200 litres an hour) and a 5 litre bucket, had my machine running for 4 hours yesterday afternoon and the water was only just tepid. I am planning on putting a PC rad and fan on the y axis but that's a long way off yet I think!

You don't need much of a pump as, once the pipework is filled, you are just pushing liquid around a balanced system, assuming that the return pipe goes down to the tank that you're drawing from. I use a little water pump as sold for caravans; I have a switch that lets me use the full 12V for initial filling and purging of air, then I can go to 5V. Like others, I just use a bucket.

Thanks for the tips. Great I'll use a simple tupperware box then..


I think I'll buy a cheap 120mm aluminium chinese no name radiator for it then.


Am I right to assume that the cooling system inside the spindle will be aluminium? Hence it's better to keep the rad and connections aluminium too for anti corrosion?

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Originally Posted by d4cnc

Am I right to assume that the cooling system inside the spindle will be aluminium? Hence it's better to keep the rad and connections aluminium too for anti corrosion?

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Yes

... with regards to fittings... should I be looking for aluminium fittings too? As they appear to be hiding from me at present.. what does everyone else do?

Do you just go with nickel plated / chrome plated brass fittings and make sure your coolant has some anti corrosion additives?
Or plastic ones perhaps?

I presume you can just use glycol based car antifreeze as a corrosion inhibitor for aluminium systems. I hope so as I have got the best part of 5L left over from the days when you changed coolant every year.

Quote:

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Originally Posted by d4cnc

... with regards to fittings... should I be looking for aluminium fittings too? As they appear to be hiding from me at present.. what does everyone else do?

Do you just go with nickel plated / chrome plated brass fittings and make sure your coolant has some anti corrosion additives?
Or plastic ones perhaps?

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You can use either brass. chrome or plastic and has been said a little antifreeze if it has a chance of freezing

I was given a 120mm radiator from a computer cooler which had a seized pump. The liquid inside the sealed system seemed to be pure ethylene glycol. Glycol has a better heat transfer than water (they used to use it for cooling Spitfire engines) and as I have 4L of undiluted antifreeze, I was thinking of using that, if it isn't too viscous for the pump to handle. The radiator has rubber hoses fitted, and I have plenty of 8mm pipe and pneumatic push-in fittings. It'll be a long time before I get to fitting the cooling system to my machine, which is at the plans done and steel bought stage. Now I just need my wife to stop finding me jobs to do, so I can get on with the build in peace.

Cheers,

Rob