Spindle water cooling 101. The right way.

[diyengineer]

What this isn't:
Everyone does things a bit different. By no means is this an attack on people who like to do things on the cheap. Sometimes it works, but never as good as doing it in the correct manner. Below, is more or less a system for people who would like commercial quality AND longevity out of there cooling system, and don't mind spending <$200 (roughly) dollars on the entire setup. Once again, for people that are cheap, or love the inexpensive route, please don't read further. Also don't bother telling everyone how you hooked up a garbage can with 2 tubes and used a pond pump. I'm glad it works for you, but some people want a bit better option than a pond pump and a barrel, especially when the machine they own, costs thousands or tens of thousands of dollars. Is this the only quality solution? Obviously not, but its a damn good one.

Lets see since its a aluminum water jacket, make sure not to introduce copper into the system or you will get galvanic corrosion, with water being the transfer medium. If you are A-ok in that department, use "PROPER" liquid AND tubing that is made for thermal heat transfer AND resists (or eliminates in some cases) the chance of microbial build up.

For the quick job here and there distilled water works fine, if you plan on flushing and cleaning a lot (depending on the use of the machine, "I" would flush at least once a month) The warm dark spindle cavity is the perfect petri dish for bacterial growth to form. (Also PVC tubing is horrid from Home Depot).

For those of you who do something, oh what's it called... oh yes, its called the "correct way". Look at what Tygon (tubing manufacture) has to offer in its silver lined anti-microbial tubing. Its the best out there, i believe 3M makes something alike which would also work. That is only half the battle! The fluid needs to transfer heat, as well as resist clogging, clotting and microbial build up, and offer something just in case it leaks, like having a very low electrical conductivity. For probably less than $100 dollars easily (for tubing and coolant), if not $50 dollars you can really save yourself a MONSTER headache, and a lot of unnecessary maintenance, which in turn is wasted time=wasted money. (I have also included a small radiator, and a water pump which is way better than those throw away junk pond pumps. This setup could go 24/7 no worries for more than a year at least, is my prediction.) So anyone looking at a more commercial application that you don't have to baby sit, and is not ghetto check it out.

Fluid:
http://fluidxp.com/index.php?option=...d=26&Itemid=65

Tubing:
http://www.tygon.com/tygon-antimicrobial-tubing.aspx

Radiator:
http://www.newegg.com/Product/Produc...82E16835108086

Pump:
http://www.newegg.com/Product/Produc...82E16835108063

The pump and fan can be powered with almost any 12V wall wart power supply that meets the power requirements. If you have the space, almost the entire cooling unit can be mounted above the spindle. It takes up a very small foot print. If you plan on running the machine commercially i would look into a micro atx power supply instead of a wall wart.

I hope this will help the few people who really like quality, i have literally used 100's of Laing pumps and gallon after gallon of the coolant, cases of radiators, and yards of that tubing so i can highly vouch for all the products. This is how i plan on cooling my spindle, so hopefully i can produce some slick pictures soon.

Thank you for your time.

[Teyber12]

I see we have a computer- watercooler here

I am in the process of making pump tops for the laing ddc pump you posted.

Good write- up

[kawazuki]

Originally Posted by diyengineer Lets see since its a aluminum water jacket, make sure not to introduce copper into the system or you will get galvanic corrosion, with water being the transfer medium.

Well done - you've managed to fall at the first fence! The Radiator is brass and copper! Also using an aluminium cooling jacket will still react to the spindle metal (steel / stainless) unless its a bolt on jacket that relies on thermal transfer? which is never as good as direct contact!

Why bother worrying about microbial effects - its a sealed system (apart from an expansion vessel / tank) and your not planning to drink it! More applicable is algae growth which really makes a mess although opaque tubing and proper coolant concentrations helps! Tygon is good so is plain silicone hose - pays yer $ takes yer choice!

[Herbertkabi]

hi everyone,
I do use milling coolant for Spindle cooling.
Machine -> coolant collector -> robust filter -> fine filter -> tank -> Pump -> Spindle in -> Spindle out -> modular coolant nozzle
In some my spindles modular nozzle comes direct from spindle, others have hose between. Pump is small 12v brushless, plastic (eBay), hose 6mm ID,
When spindle starts - at the same time coolant pump does.
I do use different kind of coolants what found via eBay, mixed with water.
Milling mainly aluminium, mostly 7075 ...
10.000 ... 30.000 rpm, 6mm ... 1,6 mm endmills.
Cheers,
Herbert

[daviddecker]

The radiator mentioned in the post does contain copper. Most of what is available for computers does. Another alternative may be an all-aluminum radiator for a small car or motorcycle. You can pick these up on ebay for fairly cheap (for example Item number: 320524883677 $50)

[diyengineer]

Originally Posted by kawazuki Well done - you've managed to fall at the first fence! The Radiator is brass and copper! Also using an aluminium cooling jacket will still react to the spindle metal (steel / stainless) unless its a bolt on jacket that relies on thermal transfer? which is never as good as direct contact! Why bother worrying about microbial effects - its a sealed system (apart from an expansion vessel / tank) and your not planning to drink it! More applicable is algae growth which really makes a mess although opaque tubing and proper coolant concentrations helps! Tygon is good so is plain silicone hose - pays yer $ takes yer choice!

The radiator is copper finned, the lines that touch the water are pure brass and will not create galvanic corrosion. All "wetted" parts are stainless i believe in the pump. the radiator is VERY impressive, and transfers heat VERY well. Be sure to use at least a 100+cfm fan (minimum). Since your spindle will be louder than 50-60db i would suggest running a 150-200cfm fan for maximum cooling.

why worry about microbial build up? Sure if it is a sealed system in a clean room, with clean water then the chances of build up are far lessened. Try running normal tap water in a sealed computer loop for 1-6 months. The gunk, mostly algae and other microbes can literally clog your pump and bring the entire system to its knees. Plus it drastically reduces overall cooling performance, leaching to just about any solid surface (these surfaces are then coated with microbes that don't like to transfer heat). Additionally if it is a sealed system the volume of the water can expand and contract roughly 10% with heat. so make sure you have a small reservoir. filling the system to the max, and measuring the volume-10% usually is a good rule of thumb but usually cannot be accomplished due to radiator restrictions. If you were to fill your system to the max with room temp water, then run it till it warms up pressure is created and could possibly blow a fitting off, a line off, a seal out, etc. Usually the tubing will expand the difference to lessen the hydraulic pressure.

I would suggest plain silicon a bare minimum if you dont go with tygon. I use to use silicon but the local automotive shops charged a lot of money, and it came out to be the same price as me ordering tygon from a local distributer.

That PVC based stuff is just hell. Besides yellowing, leaching, breaking down, stretching out, it is just plain useless. Avoid it all costs. haha

[diyengineer]

Originally Posted by daviddecker The radiator mentioned in the post does contain copper. Most of what is available for computers does. Another alternative may be an all-aluminum radiator for a small car or motorcycle. You can pick these up on ebay for fairly cheap (for example Item number: 320524883677 $50)

The copper is not WETTED. Only the brass is wetted. I have cut them open before.

[diyengineer]

"Brass body and tubes, louvered copper fins"

If you don't believe me on cutting at least probably 4 or 5 of these apart, there are the specs word for word from the manufacturer.

Can be found off the radiator link: then navigate to specifications.

I don't know where people are getting the idea that the copper is wetted lol.

[kawazuki]

Originally Posted by diyengineer "Brass body and tubes, louvered copper fins" If you don't believe me on cutting at least probably 4 or 5 of these apart, there are the specs word for word from the manufacturer. Can be found off the radiator link: then navigate to specifications. I don't know where people are getting the idea that the copper is wetted lol.

What is brass? An alloy of copper and tin! You've basically got a mix of 3 or 4 different metals - galvanic corrosion will happen to a greater or lesser extent!
Either go all copper (expensive) or all ally (although that isn't pain free either!) Personally I like Herbertkabi's method - vat of coolant, cool spindle with it, drains to flood cool tool, back to vat to cool and recycle.

[Herbertkabi]

Originally Posted by kawazuki What is brass? An alloy of copper and tin! You've basically got a mix of 3 or 4 different metals - galvanic corrosion will happen to a greater or lesser extent! Either go all copper (expensive) or all ally (although that isn't pain free either!) Personally I like Herbertkabi's method - vat of coolant, cool spindle with it, drains to flood cool tool, back to vat to cool and recycle.

hi kawazuki,

http://helicam.ee/cnc/CNC1.mov
there all speeds was bit reduced because want to keep my camera clean.

Yes, my system is problemless when milling aliminium and other metals, even carbon laminates does not matter, I have worked with more than half year.
but
yesterday evening started with mould making, oh dear, right now I forgot how to call this material, have softer and harder, this current one is hard ... and it totally did clog up the fine filter OK, I already cleaned and washed but now I think I need to clean and wash collector tub and multilayer cheesecloth as well, and after that to put one aditional multilayer filter-bag on to this white rectangle collector (goes to collector tub).

But as told before - with metals and with common plastics not any problems.

There is two pumps - one (direct left from fine filter) is for coolant/cooling,
second one (car wind.) I use for machine washing (not washed right now)

cheers,
herbert,

and one thing more, kawazuki,
brass = copper + zink
Copper + tin = bronze

[cjdavis618]

I would like to add, for the fan, please use a Higher CFM fan to blow air over the fins. If you have a low cfm fan, you might as well blow on it yourself.

[kawazuki]

Originally Posted by Herbertkabi and one thing more, kawazuki, brass = copper + zink Copper + tin = bronze

I stand corrected - least I got the copper bit right! LOL And zinc is usually more reactive than either or so I remember from school chemistry?