X carve upgrade to .8KW water cooled spindle W closed loop cooling

Hey guys,

So this is a short post about my upgrade for the .8KW VFD water cooled spindle. I have been using the 48V 400W DC spindle on my Shapeoko 2 to mill in aluminum and the results have been really good.

But now with a new X carve I felt I would push the limits a bit and see how the X carve would stand up to milling aluminum with the .8KW water cooled 65mm VFD spindle. I have the Shapeoko still up and running so I am able to test a few ideas out and move parts around a bit to see this through I think. I had a slight delay in my X Carve build while I waited for a replacement belt clip which was bent in the wrong place when it arrived so i hit CAD and worked up the following.

This is based on trading out the Shapeoko spindle mount plate with the one from the X Carve (these can also be bought for under $10 (plus shipping) from Inventables. The X Carve mount was a great fit/upgrade on the Shapeoko.

At the same time I also did the Z axis belt drive upgrade for the Shapeoko so the Spindle can have the full travel of the Z axis like the X Carve enjoys. After a full night of cutting carbon fiber it seems like a great fit and a very worth while upgrade over my old 3D printed mount for the 400W spindle.

So the new mount was 3D printed to check for size and fit. The results look great and I plan to use them to mount the .8KW spindle to the X Carve just long enough to mill the new spindle mounts out of of some Alca 5 tool plate.

For an idea of size you can refer to this pic.

From top to Bottom: 24V 300 w Stock X Carve spindle , 48v 400W spindle, .8KW 1HP water cooled 65mm VFD spindle, 1.5KW 2HP water cooled 80MM VFD spindle (For my large 21x37 mill)

I will be doing a closed loop cooling system much like a water cooled PC. The .8KW spindle will use a single 120mm radiator with two high static pressure fans built for radiators. A small pump will keep the coolant flowing in the system while hooked up to the VFD unit which will turn it on and off with the spindle.

Right now the control unit for my X Carve build is up in the air. I have the stock Gshield but will either be testing a new X Controller shortly, or going with another TinyG for the main controller. Although full Leadshine DSP drivers with a planetCNC MK3/4 will end up being the controller in the long run I think so I can bring the OKO and X Carve more inline with my larger mill which runs on PlanetCNC controllers. Either way a PWM to 0-10v converter will feed the Gcode spindle speeds to the VFD and allow full spindle control.

Tomorrow I plan to knock out the final aspects of the X Carve build and start working to get the new mount on and ready for milling the real mounts in aluminum.

Updates to come and always welcome any questions.


I’ve heard a lot mentioned on the forum about water cooled VFD spindles and it looks like you are well on your way to figuring out the implementation aspect. What are the basic specifications of the 0.8kW and 1.5kW spindles? They look much beefier than the other quiet cut spindles; how do they compare noise-wise? Thanks :smile:

I ordered a .8kW VFD spindle as well, which will probably arrive in a couple of weeks. I’d love to see more details about your cooling solution, as I still need to source parts for that.

The mount looks pretty cool. I was planning on taking the cast aluminum mount included with the VFD spindle, and drilling mounting holes to match a shapeoko mounting plate. (Or I might get one of the 611 mounts if they are available)

Here’s the components I used on my .8KW VFD water cooled spindle, All from Amazon. Runs super quiet and hasn’t got past warm to the touch. As for the mount I made one until the 611 mount is released.

Clear Tube

Water Pump

Heat Exchanger Radiator

120mm Fan


Pretty much the same setup for me aside from the tubing. I used a slightly more powerful pump as I might have a long tubing run on my setup due to space issues so needed the more powerful pump. I am going to stick with my mount I think for now over the 611 mount as I do not like to shim things and what I was seeing at the Inventables workshop when I visited a few weeks ago, was they had to shim the spindle to make it fit in the larger 611 mount. Not much but I dislike shims for parts like that so I choose to mill my own for now.

I should have mine setup by the weekend and will post tons more photos and info by then.

How did you do the speed control David? Also what CNC controller are you running? I am thinking of just doing a second TinyG and going from there until the X controller test unit shows up.

Are you guys using plain water, or propylene glycol or something like that? How much coolant do you use?

I have a water cooling setup on my laser cutter, it just uses a submersible pump, a bucket of steam distilled water, and some tubing (I think the tubing is latex). No radiator, but the specific heat of the bucket of water is more than enough to cool the laser over a typical cutting job (usually not more than an hour)

It all works pretty well, but the water tends to grow some of those clear slime cultures after a while. By my numbers, an 800W spindle puts out about 3 or 4 times as much heat as a 40W (output) laser tube, so that might be why the radiator is there.

I use a none conductive coolant like I use in my “water” cooled PC builds. I choose to use a radiator and be a “closed loop” system since I did not want a bucket of water in the mill room that could be tipped over. By keeping the system closed I can mount everything where I want and do not worry about spills and such. Also as a closed system there is no need to “top it off”. Most folks just run the bucket like you speak of and distilled water or RO/DI water. NEVER use tap water in your system. I use the coolants I do to reduce the issues with so many kinds of metals in the loop of the system. They also have an additive to stop the growths you spoke of and I use a few coils of pure silver in the tubing to kill the microbes and stop those growths from happening. So overall my system is a computer cooling system with a few small changes made for the spindle.

oh man thats sweet.

I just control the speed on the VFD for now. Other than the spindle, everything is stock 1000mm setup. Right now I’m using plain distilled water. I placed the sub pump in a small container with a lid, drilled holes big enough so the tubing will snugly slide thru. It’s only been about a week but nothing has started growing. I’ve read biocide treatment or little bit of radiator fluid but I’ll see how the water holds up. As for how much coolant/water to use, depending on how long the lines are, as much as it takes for the sub pump to stay submerged while running.

i do plenty of PC watercooling. a silver coil is a natural biocide. but distilled water will do you good for months before you need to swap it out if its a closes system not open to the air.


What do you guys think of using an all in one cooling solution like this?


I would still need a 12V supply for the pump and fan. Can you get 12V off of the x-carve PSU?

should get the job done unless the spindle requires extra cooling then its going to be tricky to upgrade your radiator however you could probably just add another to the loop in theory. just depends on how much heat those things put out and how efficient the cooling solution is. my guess is your going to want something with a 240mm radiator minimum if not larger. and go with push pull fans, corsair sp120s are well priced unless you want to go ahead and get Delta fans that are larger than the normal 25mm thickness.

more expensive but boy do they push air. probably get away with using just 2 fans if you get these http://www.amazon.com/Swellder-AFC1212DE-120mmx38mm-Bearing-BRUSHLESS/dp/B00XDXX01C/ref=sr_1_13?ie=UTF8&qid=1435781083&sr=8-13&keywords=delta+fan+120mm

The very thing I use and love!

Guys make sure you pay attention to the sizes on the connections for this application. Most of the Spindles out of china tend to have a smaller connection size than the “stock” G1/4 (3/8ID 5/8OD) connections on the coolers. I just put a small converter tube in mine and it seems to work fine in testing so far. Just keep on eye on the tube and connection sizes though so you do not hit a roadblock due to that when you put your system into place.

well the G1/4 connections are the same as what PC watercooling uses which kinda standardizes everything. especially if your trying to put radiators up and what not. but yes i have found out the hard way. check all the specifications… i ordered some end mills with 3/8" shafts… and i dont have a collet for that. didnt read all the perimeters of the bits. lesson learned.

if you want to use a non submergence pump i’d recommend going with either a DDC or a D5 style pump. DDC is more heavy duty. and D5 is abit less powerful but better for tight spaces. both of those pumps are ultra common in water cooling PC’s so there is a ton of accessories, tops, mounts, fittings to fit either style pump. (neither is really inexpensive however)

http://www.performance-pcs.com/ is a good resource for PC watercooling equipment and would also have supplies that may be relevant to this application.

This issue I found before I placed my orders was that the connections on the spindle were not a standard G1/4 size. They are a bit smaller and will not allow standard tubing to be used for G1/4 connections. SOME spindles have the larger “right” sized connections as they are a replaceable part and can be changed. But they are not easy to find and not cheap either I found. Basically my system runs 90% G1/4 tubing and then changes over to the “spindle” tubing just outside my mill box and then run to and from the spindle in the “spindle” sized tubing. So far this has worked fine for me. I use the 1/4" ID, 1/32" wall Thickness, 5/16" OD Latoratory clear Tygon PVC - See more at: 5/16″ OD Laboratory clear Tygon PVC Tube For Spindle Cooling System $1.84/feet | sized tubing. Though I sourced it from someplace else in bulk for cheaper. But most guys do not need or desire 35ft of it for any reason!
I do wish they were all the G1/4 sized connections as it would be one less thing to get setup on a new system.

I am going with the 0.8kW water cooled spindle too. It was mentioned ( X-Carve Spindles - #19 by BartDring ) the power and water lines wont fit in the stock drag chain. Is the standard kit one 30mm? If so, Has anyone tried a 40mm to see if the water lines and power would all fit?

I wouldn’t try to put the power and water lines into the drag chain. I was planning on just running that over the top. I don’t think the water line would stand all the bending and motion of the drag chain, and you probably don’t want to have the 400HZ AC lines in there causing interference with the stepper lines.