My homemade brushless spindle v2

3kw 1050kv 24v water cooled brushless motor.
3x 7204 angular contact bearings.
1x 46mm OD wave spring washer.
Main housing is 60mm.
I'll add a water cooling jacket to the main housing so it'll have 2 cooling jacket. One for motor and one for main housing.
Collet chuck shaft diameter is 20mm and length is 100mm.
There is a one way bearing inside the collet shaft. I've added this to connect the motor shaft to the chuck shaft. OWB dimensions are 12mm ID, 18mm OD and 12mm length.

I'm not sure if I'll need to add an oil seal to the far bottom bearing. I'll gladly accept any suggestions.

Here is the design so far.

I AM GLAD TO TAKE THIS OPPORTUNITY TO INTRODUCE OURSELVES AS ONE OF THE LEADING SUPPLIERSOF PRECISION BEARINGS MAINLYAPPLY FOR CNC AND MACHINE TOOL AND OTHERPRECIAION MACHINARY , WHICH ARE MAKE OF WAFANGDIAN TIANJIU BEARINGS TECHNOLOGY CO.,LTD.

WE DEVELOP HIGH-PRECISION YRT ROTATED BEARINGS, MACHINE TOOL MAINSHAFT BEARINGS AND MOTOR PRECISION BEARINGS. THEPRECISIONS OF OUR BEARINGS HAVE REACHED LEVELS OF P5, SP, P4 AND UP.

WE HOPE CAN CORPORATION WITH YOUR COMPANY.IF ANY RELATED INQUIRY,PLEASE FEEL FREE TO CONTACT WITH US.

WE CAN ALSO SUPPLY BEARINGS SAMPLE FOR YOUR AT FIRST.

WE CAN SUPPLY OUR BEST PRODUCTS FOR YOU.

THANK YOU !

REGARDS！

--------------------------

Lixingwen

Wafangdian Tianjiu Bearings Technology Co.,Ltd.

(Wafangdian Heavy Bearings Researching & Manufacturing Co.,Ltd.)

Brand：WZFB

Web: 瓦房店天久轴承科技有限公司（原 瓦房店重型轴承研究制造有限公司）

Tel: 0411-85366785

Fax: 0411-85366785

Mobile:+86-15942617721

E-mail:[email protected]

Q Q : 178702120

Skype: lixingwen1987

Do our best to give customer best service.

http://puu.sh/b7CaV/0e5cbda73e.JPG
http://puu.sh/b7Cfw/16c4b12b2a.JPG
http://puu.sh/b7Ch5/08ca7bc06a.JPG
http://puu.sh/b7Ci5/f8614e0992.JPG
http://puu.sh/b7Cjc/baa46d8794.JPG
http://puu.sh/b7Cko/53e92caba2.JPG

I would be interested to know how well it works. Whats the TIR? What is the usable Min/Max RPMS?

How did you couple the motor shaft to the collet shaft?

I used a one way bearing to couple motor shaft to collet shaft. Please see the image.

As for the speed, spindle will go up to 25k RPM with 24v. I haven't tried it yet but the motor is rated as 3kw power. Should be enough.

I'm curious to know what keeps the shaft from moving up and down, as I don't see any shoulders on the shaft? Are you relying on press fit bearings for this?

Hi manton,

You don't see it in the design image but there is a shoulder in the collet shaft.

The shoulder stops it sliding up in the bearings, but what stops the shaft pulling out? What preload the nose bearing pair together?

Did you need to resize your shaft to fit the bearings? I have an chinese ER16 with 20mm shaft and it is slightly oversized. I picked up a pair of P2 precision 7204 AC bearings off Ebay, but will need to grind the shaft OD for a fit to the bearings.

Have you thought about turning a labrinth seal to keep dust out of the bearings?

What run out are you getting in the collet cone and out on the tool shafts?

Do you have a part number for that clutch bearing please?

Hi Mark,

I don't recommend one way bearings to couple shafts as they stop holding at higher speeds over 12k. I'm not going to use them on my new build.

You are right. Some of the collet shafts are over sized. You need to hammer to fit your bearings.

I used a clamp above the top bearing so the wave washer keeps all the bearings loaded.

Thanks for that speed limit on the one way bearings. Do you mind posting a photo of your clamp please?

No way am I going to hammer precision bearings. I'll set up my tool post grinder and sort out the shaft diameter. Otherwise it would have been a waste to buy top bearings.

Cool stuff. Makes me want to build one for my mill. Do you have to run coolant on the motor? I have run a few 50mm brushless motors on some longboards just a bit shy of your power but they were all air cooled.

Quote:

---

Originally Posted by RotarySMP

Thanks for that speed limit on the one way bearings. Do you mind posting a photo of your clamp please?

No way am I going to hammer precision bearings. I'll set up my tool post grinder and sort out the shaft diameter. Otherwise it would have been a waste to buy top bearings.

---

It's just a clamp I cut from SS in my lathe. It has a 20mm ID with 4 set screws.

Sent from my SM-G900F using Tapatalk 2

Quote:

---

Originally Posted by rs4race

Cool stuff. Makes me want to build one for my mill. Do you have to run coolant on the motor? I have run a few 50mm brushless motors on some longboards just a bit shy of your power but they were all air cooled.

---

Yes the brushless motor has a water jacket.

Thanks.

Sent from my SM-G900F using Tapatalk 2

Quote:

---

Originally Posted by RotarySMP

No way am I going to hammer precision bearings. I'll set up my tool post grinder and sort out the shaft diameter. Otherwise it would have been a waste to buy top bearings.

---

I agree but I think you'll have to regrind your collet taper after grinding the OD to prevent excessive runout.

I think grinding the shaft will probably not end up well.

I asked the seller about the excessive dimension and he told me that some of the collet shafts machined over sized for a hard fit so using a clamp is not needed. I know this sounds stupid but that's what he told me. The collet I used in this spindle is made in Turkey and it is very well machined. Super quality. The shaft is just in perfect dimension, no hammering needed.

I say that the Chinese items are not cheap anymore. Pretty expensive for the quality actually.

Do you have a link to that Turkish collet chuck? If they have better control of the shaft diameter, it would be easier to get one than muck around grinding the shaft. I assume I'll need to regrind the tool taper anyway, one the shaft is running in its own bearings.

Mark,

That's a small local dealer. I don't think even if they have a web site but I can ask if they can ship overseas.

I'll measure tonight the cone to see the run-out.