Cooling a water cooled spindle, without pipes everywhere & huge water tanks/buckets!

So I've got a small CNC machine (30 x 20), it's got a water cooled spindle (which I've not used yet)...but frankly the thought of tubes running back to a large bucket, which will no doubt get contaminated seems excessive (bearing in mind my CNC machine is located in - what was meant to be - our dining room!


So I seek a compact & silent (ok, perhaps silent is stretching it ....let's say very low noise) solution ....something that's a closed loop (so I don't have to worry about contamination). So I;m browsingebay (as you do) & found this....

New Silent 23DB Water Cooling Circulation Pump For Spindle Motor CNC Router | eBay

...ok, yep, a Chinese seller & as usual, this isn't so much an advert, more of a teaser for you to try & piece together th puzzle. So to my question....would this suffice for cooling an 800W spindle? Would it even be suitable? Would it need a cooling rad to be used in conjunction with it? (I should perhaps mention that the machine isn't on the go for hours - probably maximum session is about 40 minutes...and even then the spindle isn't be overly taxed...probably running at 10,000RPM milling a PCB or cutting a bit of acrylic.

Many thanks,
Hank.

I been having a bit of a read of the Chinese spindle thread and from what is being said there the cooling requirements aren't that hard to meet.

I'm currently thinking of mounting a radiator on the back of my gantry with a small pump on top thus limiting the pipe run and total water volume. I was thinking I'd probably use a modified computer cooling system. As Jonathan mentions in this post the dissipated heat is probably of the order of 110W max. Cooling systems for CPUs have to be able to deal with 80W and probably quite a bit more because people using water cooling are often over clocking. If you are willing to run with a reasonable delta temperature (between ambient and radiator) passive cooling should be quite easy. If you want a smaller delta then a 12V computer fan run at 7V would provide good air flow over a radiator and be essentially silent.

If the system is closed loop, then without a reasonably large tank you will certainly need a radiator of some sort. The easiest option is just to use the parts people use for computer water cooling systems, but the parts for that market tend to be overpriced so unless you can get lucky on eBay I'd substitute them for cheaper options, e.g. the pump you found and a car radiator with a fan for the heat exchanger. I don't think you'll get away without a fan unless you have an unreasonably large heatsink.

It's been done before:
Spindle Water Cooling System Test Start - YouTube

That system looks nice and light.

Quote:

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Originally Posted by Jonathan

If the system is closed loop, then without a reasonably large tank you will certainly need a radiator of some sort. The easiest option is just to use the parts people use for computer water cooling systems, but the parts for that market tend to be overpriced so unless you can get lucky on eBay I'd substitute them for cheaper options, e.g. the pump you found and a car radiator with a fan for the heat exchanger. I don't think you'll get away without a fan unless you have an unreasonably large heatsink.

It's been done before:
Spindle Water Cooling System Test Start - YouTube

That system looks nice and light.

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The pump in that youtube video looks like the same item I linked to in my first post (which is quite cheap) ...

DC12V SC-300 Silent 23DB Water Cooling Circulation Pump For Spindle Motor Router | eBay


just where to buy the radiator with integral fan, I found a radiator that seems well priced (so might just lob a quiet fan onto it)....

Aluminum Water Cooling Block Water cooled Row Heat exchanger For PC Computer 90 | eBay


I'm ideally seeking a solution that can be mouted on the rear of the gantry of a 3020 machine (fixed gantry type)

I wouldn't worry about getting an integral fan with the radiator. Fans are cheap and you'll probably want a half way decent "ultra quiet" one (something like this).

No need for radiator. Just a waste of money. 1000l/ph pump + 5l car radiator fluid+ big transparent 5l jar from any chinese shop + transparent plastic hoses. Again, anything else is a waste of money. Thats for 0.8kw spindle. 15l have to be ok for the 2.2kw one.

-Water cools also in the plastic tubing on its way
-The tubing should be transparent so you can see eventual bubles
-the car liquid takes away heat better/glycol/ and will not spoil with time/at least for an year, later-yes/
-the car cooling liquid has a color so you can spot leaks
-the jar should be transparent so at all times you see the flow

Never had any problems with this setup doing more than 8h continuous machining.


This is the correct pump 75W Water Pump spindle motor water-cooled circle pump For Engraving machine CNC | eBay

I bought the same locally for 20euro but this one is better because of the brass fitting.

Hope it helps.

Quote:

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Originally Posted by silyavski

No need for radiator. Just a waste of money. 1000l/ph pump + 5l car radiator fluid+ big transparent 5l jar from any chinese shop

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In most circumstances, that's true, but if you're trying to get away without a tank a radiator is certainly needed. For my 2.2kW spindle I have a tank which is filled with about 8L and it's not really enough for more than a few hours. Clearly it depends on how much power you're drawing from the spindle, but 5L of fluid will only be able to absorb the heat for a very short amount of time if the spindle is used at anywhere near rated power. You must be using only a fraction of the rating to get away with 5L.
In Hank's case it's a small spindle on a small machine, so it might be acceptable.

There are plenty of cheaper pumps on eBay...

Quote:

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Originally Posted by Jonathan

In most circumstances, that's true, but if you're trying to get away without a tank a radiator is certainly needed. For my 2.2kW spindle I have a tank which is filled with about 8L and it's not really enough for more than a few hours. Clearly it depends on how much power you're drawing from the spindle, but 5L of fluid will only be able to absorb the heat for a very short amount of time if the spindle is used at anywhere near rated power. You must be using only a fraction of the rating to get away with 5L.
In Hank's case it's a small spindle on a small machine, so it might be acceptable.

There are plenty of cheaper pumps on eBay...

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Sorry, forgot to say 0.8kw spindle, so like you say multiply by 3 the water amount. Will edit now my post.

However my water doent heat at all obviously because of the long hosing/ i have it run inside the cable chain guides.


I encourage greatly liquid versus radiator. One more thing to fail/fan/.

I've got a car screenwash tank with inbuilt pump. I planned to run it at 6V or so as it's not meant to run continuously, and running at 12V I think the flow will be way more than needed.

Only problem is how to attach a return connector to the top, and making a wooden crade for it. If it proves too difficult (maybe it's polypropylene which won't glue) I might try using a small car header tank and I've got a small brushless pump which will be fine for continuous duty.

Quote:

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Originally Posted by richie00boy

I've got a car screenwash tank with inbuilt pump. I planned to run it at 6V or so as it's not meant to run continuously, and running at 12V I think the flow will be way more than needed.

Only problem is how to attach a return connector to the top, and making a wooden crade for it. If it proves too difficult (maybe it's polypropylene which won't glue) I might try using a small car header tank and I've got a small brushless pump which will be fine for continuous duty.

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Hi,
in fact i did just the same at the beginning. It will heat and eventually break. I had a Mercedes screenwash water tank and VDO brand pump. I fixed a PC cooler fan on the pump and run it at 6v. One day it broke. It heated a lot and made a lot of noise.

Its up to you but if you go to a local pet store for 20eur you can have a perfect 1000lph pump, if you dont want spending 32euro on the ebay one/3000lph/.

As it's in your dining room why not pump it through a wall mounted central heating radiator, nobody would notice it and it would heat the room in winter.

I'd guess a 2.2kw spindle will produce far less than 500W heat, as electic motors are 90%+ efficient, and the bearing friction won't contribute that much to heat.
Personally, I'd opt for a copper coil. Get a coil of 8 or 10mm copper pipe, make some holders to space and secure it (basically some bits of MDF/Plywood notched out to accept the pipe) and pipe it up. You'll still need some kind of tank to allow for expansion though.

I certainly wouldn't be using a car radiator, as they're designed to deal with 10's of KW of heat. A heater matrix would be more suitable, but it's quite hard to get them with basic pipe connections, and it's not worth scrapyards removing them as they take that long to get into.

Quote:

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Originally Posted by silyavski

Hi,
in fact i did just the same at the beginning. It will heat and eventually break. I had a Mercedes screenwash water tank and VDO brand pump. I fixed a PC cooler fan on the pump and run it at 6v. One day it broke. It heated a lot and made a lot of noise.

Its up to you but if you go to a local pet store for 20eur you can have a perfect 1000lph pump, if you dont want spending 32euro on the ebay one/3000lph/.

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What power spindle was that with? Mine is 800W.

I'm actually leaning more towards using the separate pump and container as I'm not really that convinced the screenwash pump will last very long. I had a brainwave today on the tank. I've got a tall small footprint plastic food container that could be a good tank and I can make some bulkhead mounting pipe fittings using hosetail connectors and a nut and washer.

Quote:

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Originally Posted by richie00boy

What power spindle was that with? Mine is 800W.

I'm actually leaning more towards using the separate pump and container as I'm not really that convinced the screenwash pump will last very long. I had a brainwave today on the tank. I've got a tall small footprint plastic food container that could be a good tank and I can make some bulkhead mounting pipe fittings using hosetail connectors and a nut and washer.

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Hi,
My spindle is 800w. Thats what i am telling you, the screenwash pump will not last even if coooled by pc fan and makes a lot of noise, plus you need a 2-3A power supply at least to run it. Will not run with a smaller than 1A.

Here is a picture of my setup. Note that at the picture is not seen but now i have a bar which is fixed to the spindle and holds together the cable and the housing straight vertical, to avoid twisting of the cable and the hose. As this bloody chinese spindle cable connection was giving me problems:

Attachment 9971

Ok ...water pumps.

it seems the plastic tubing spec for the water cooled spindle is 8mm OD & 5mm ID ...but most of the water pumps on Ebay seem to have nothing of the sort...so is everyone using water pumps with reducers/adapters?

If you are only cutting/drilling pcb and other soft materials. do you even need to bother with cooling? I have been running my wc spindle without cooling for about 10 years now and have never felt the spindle get hotter than hand warm. Obviously if I was doing very long runs cutting hard materials I would keep checking it did not overheat, but to date I have never had need to water cool. G.

Dunno...never had one. I just assumed the fact that they were called water cooled spindles meant you had to water cool 'em!

I'll probably be running jobs for about 45mins to 1 hour max ....but for the sake of a pump & a bucket I think I'd rather err on the side of caution (my machine already has the plastic tubing installed into its loom, so I only need to add a pump & I'm off to the races - but like I say...which pump, which outlets!)

My pump has 8mm connections and I was assuming/hoping that the 6mm tubing would stretch enough to go on...