Spindle Mount for 80mm VFD Spindle (STL attached)

I just finished upgrading my machine, replacing the X axis with a solid 40x40 open build beam and rails setup. Then I bolted on a 1.5KW water cooled VFD with an 80mm outer diameter.

I had originally bought the .8KW but released the magic smoke by not setting PID 004 to the correct value, the place I bought the motor was out of stock of the .8KW when I bought the replacement so I went with the 1.5KW. I had to design up a new motor mount to fit the larger motor, I based it off of a design @Travelphotog had originally posted. This spindle mount is designed to attach to the universal plate: https://www.inventables.com/technologies/spindle-mounting-plate

Outter.stl (3.9 MB)
Inner.stl (4.0 MB)


I did the same mod. Along with the eccentric spacer thing. Much stiffer. Went from 30-40 ipm to 100-120 ipm. Haven’t even done the y axis yet.

The 40x40 is $20. The linear rails are $6 each X 4. And i ordered a 5x25ea bags of M5 X 8mm low profile screws for $16 and the same in T-Nuts for $25. I have a lot left over. Wasn’t sure how many I would need. But nothing wrong with extras lol. I did the eccentrics and the belts and pulleys, got some spacers. My entire order was $211 with shipping from Openbuilds. But it’s basically a complete tear down to do this (at least I turned it into one). So I did everything I had wanted to do at one time. I move the eccentric spacers to the inside next to the wheels for better support.

I have not cut with it yet, just finished putting it all together last night. Though it feel a lot sturdier, especially from a torsion standpoint.

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Overall the upgrade to the rail was $85 plus shipping.

4 - Open Rail 1000mm $24

8 - 3mm Aluminium Spacers $1.20

4 - 6mm Eccentric Spacers $8.00

4 - Low Profile M5 -8mm Screws (25 pack) $12.60

4 - Tee Nuts (25 pack) $19.80

1 - 40x40 VSlot Linear Rail 1000mm $20.00


They are, I had a bunch of PC water cooling stuff sitting around, so decided to re-use it instead of buying all new.
The larger tube is 3/8 ID 1/2 OD, the bracket on the back of the motor is a quick disconnect reducer set I made.

The larger side is a male QDC with the back of it female threaded for G 1/4 and a G 1/4 threaded 1/4 barb, the bracket I designed up in Fusion 360 and 3D printed.



Which direction does your z axis twist? If you standing on the side of the machine, looking down the x axis, and the motor is twisting clockwise or counter clockwise, aka lifting or compressing toward the back of the machine, then you are dealing with torsion on your x axis.

Excellent thread Chris. Thanks for posting all the pics and stl files. Appreciate all the details because I am in the process of switching over from the DeWalt 611 to a water cooled spindle and your information here is very inspiring. Which spindle (specifically) are you using? I will be following this thread with great interest :thumbsup:

I bit the bullet and ordered a conversion kit for my larger machine. Thanks for the shopping list! The “torsion” issue is driving me nuts, especially since I upgraded my z axes to linear guides. The twisting is my only week spot not. I really hope this improves the situation! I am also hoping I can tap these ends to 6mm, because that’s what I am currently using in my custom y-axis plates.

The one thing I did not detail out that you will want to be aware of, the 40x40 beam does not just plug and play fit. You will need to elongate the oblong mounting holes a few mm. I did this using a drill press, and was a fairly simple process.

More details of the mod I made can be found here:

For spindle I am using the 1.5KW found here

In general the recommendation for the xcarve is the .8KW found here

I only ended up with the 1.5 because I cooked my .8KW by failing to set PID 004 to 400 in the vfd controller.

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Thanks. I use custom aluminum plates so elongation should be easy.

Originally wanted the .8kW but the 1.5 kW has a lower RPM setting. I look forward to your review of it.

I went for a 1.5kw myself sadly sitting here waiting on more funds to proceed - no water cooling stuff yet and a bit worried on the 2 piece sandwich. I like the way this set up looks nice job!

@ChrisMyers - thanks again for the list and inspiration! Completed the mod on Saturday. Basically took a day including milling new x-axis plates. I also swtiched to the “axle” method of mounting the v-wheels and created recessed pockets in the x-axis plates to further reduce flex (and torsion). And mounted an Ebay z-axis with a new Makita mount. The combination is impressive - WAY stiffer than ever before. I just finished milling a STONE flat and engraving a letter in it!

@PhilJohnson - I can’t recommend this enough (plus it will finally put an end to the crazy x-axis mods… “try glue!”)

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That mod looks really good, I really like the pocket and solid axle for the wheels. :slight_smile:

I used Chris Meyers’ list. There are 20 holes in the 1000 open rail so you will need 80 inserts and screws. I ordered a ton of their excentric spacers as well - they are much more robust. I did NOT order their v-wheels - which are supposedely more robust but I re-used the x-carve wheels because I have lots of extras:

4 - Open Rail 1000mm $24

8 - 3mm Aluminium Spacers $1.20

4 - 6mm Eccentric Spacers $8.00

4 - Low Profile M5 -8mm Screws (25 pack) $12.60

4 - Tee Nuts (25 pack) $19.80

1 - 40x40 VSlot Linear Rail 1000mm $20.00

The axel approach to the v-wheels has a big impact as well - you will need M5 threaded rod and four nylock nuts per axle plus washers. The spacers mentioned above had the v-wheels dead center on each rail so, it appears to be a good list.

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I tried that a few months ago and had a very hard time screwing the reversed nylock nuts (1 per axle). I remember jamming a couple and bending the axle while trying to remove them.

Did you screw them on facing the same direction instead? Alternatively, I was thinking of cutting a spacer to bridge the distance between the v-wheels around the axle. Since then I have upgraded to openbuilds v-wheels and been happy(ier).

PS. the recess on the side plates is a great idea

I put them on backwards and used a washer. Washer is critical here.

Have you measured the distance between the wheels? I imagine there is a spacer that would fit there. Even if a couple 1mm shims are required.

Im interested in how you went from the spindle’s water cooling line (4mm?) to what looks like a 1/4" pc watercooling loop with quick disconnects.

Do you have links for each of those parts?

I have some old watercooling gear laying around and really want to get rid of this stupid giant bucket of water, lol