[jimskeet]

Hi guys I have damage on my spindle bearings and they produce noise. I want to get some new ones to replace them. I don't want to open it till I have the bearings on hand though cause the spindle is still cutting fine without any issues other than the noise and I don't want to open it and then have it out of order till I find new bearings. Does anyone know what and how many bearings I need for my spindle??? I do not know exactly its brand but it is like the one in the first attachment. The second photo is my spindle on the machine. They look the same. Any help is welcome.

[mactec54]

Hi guys I have damage on my spindle bearings and they produce noise. I want to get some new ones to replace them. I don't want to open it till I have the bearings on hand though cause the spindle is still cutting fine without any issues other than the noise and I don't want to open it and then have it out of order till I find new bearings. Does anyone know what and how many bearings I need for my spindle??? I do not know exactly its brand but it is like the one in the first attachment. The second photo is my spindle on the machine. They look the same. Any help is welcome.

I have found 3 different Bearing sizes for the same spindles, so you don't have much choice, unless you have the manufacture of your spindle, it would be a guess to know the exact bearing numbers, do you have a 4 bearing or a 3 bearing spindle, they can all look, just the same

Make sure you have all the right tools to take it apart, any damage to the main rotating parts will render your spindle as Junk, everything is balanced, so care is needed, the Nut at the top of the spindle is left hand thread, and can have Loctite on the threads, so can be hard to remove, with out the right tools, same as the front Nut, it is easy to damage

[jimskeet]

Hmm thanks for the answer. Is there any guide or any video online about disassembling the spindle??

[jimskeet]

https://www.aliexpress.com/item/1-Pa...ceBeautifyAB=4

Are those bearing worth for their price??? Will they work fine or are they just chinese junk and I should avoid them and try to find more expensive bearings?

[mactec54]

https://www.aliexpress.com/item/1-Pa...ceBeautifyAB=4

Are those bearing worth for their price??? Will they work fine or are they just chinese junk and I should avoid them and try to find more expensive bearings?

They will be as good as what is in the spindle, you have to make sure you have the right AC bearings for your spindle though

[jimskeet]

I am almost sure that I have 4 bearings in my spindle after some information I gathered. So I think I need 2x7005 at the bottom and 2x7002 at the top. In worst case it has fewer bearings in it but the 7005 and 7002 will be correct. I don't think it can have a different dimension bearing in it. So in worst case I will just have extra bearings for later.
Am I right or there is a possibility of having different type of bearings other than 7005 and 7002?

[handlewanker]

Hi....buy the bearings and ask the dealer if you can get a refund on the extras or exchange them if they turn out to be different.......my supplier said "no worries, Mate".
Ian.

[A_Camera]

Is there any guide or any video online about disassembling the spindle??

Have you tried to google this time...?

https://www.google.se/search?q=disas...=1586&bih=1168

http://www.cnczone.com/forums/spindl...er-cooled.html

https://www.google.se/search?client=....0.JI8K_f2SccM

Personally, I'd buy a new spindle motor. You don't know if it is the bearings until you opened and that might be more difficult than you expect, so considering the price of these things, I'd just order a new one and would use this one until it arrives or gives some magic blue smoke. Of course, continuing to use it may result in a fried VFD as well, so maybe that's not a good idea.

[jimskeet]

Well I decided to order the bearings from aliexpress. 80$ shipped. I didn't want to go for a new spindle cause I have fixed the run out of this one and it has 0 runout inside the taper.

[A_Camera]

Well I decided to order the bearings from aliexpress. 80$ shipped. I didn't want to go for a new spindle cause I have fixed the run out of this one and it has 0 runout inside the taper.

Good luck. Ideally it should be fairly simple since technically it is a simple design, but things can become difficult quickly with Chinese machines when a tap is not according to standards, especially in a hole. I had to change all the screws when I installed an earth wire because the original screws were too thin and after removing those I realized that what held them in place before was loctite and not the threads. This was of course an easy problem to handle... I think removing the bearings may be a bit more difficult.

Anyway, how did you fix the runout without taking it apart? Interested to know the details.

[jimskeet]

Good luck. Ideally it should be fairly simple since technically it is a simple design, but things can become difficult quickly with Chinese machines when a tap is not according to standards, especially in a hole. I had to change all the screws when I installed an earth wire because the original screws were too thin and after removing those I realized that what held them in place before was loctite and not the threads. This was of course an easy problem to handle... I think removing the bearings may be a bit more difficult.

Anyway, how did you fix the runout without taking it apart? Interested to know the details.

I held this cutter on my vise and programmed the machine to run the inside taper of the spindle along it with 0.02mm stepover until it all cleaned up. Then polished it with sand paper.

[A_Camera]

I held this cutter on my vise and programmed the machine to run the inside taper of the spindle along it with 0.02mm stepover until it all cleaned up. Then polished it with sand paper.

Cool. Thanks for the information. Seems very simple. What was the rpm on the spindle? I might try this trick as well but test it on an unused DC motor first, just to get some confidence in the code...

[jimskeet]

I set the freequency at 50 so 3000rpm with 80mm/min feed. The code is easy. You can even write it manually since it is just a straight line and then a retract.

[mactec54]

I set the freequency at 50 so 3000rpm with 80mm/min feed. The code is easy. You can even write it manually since it is just a straight line and then a retract.

You can't run this spindle at 3000RPM you will damage the motor, they have a minimum RPM of 6,000, you have incorrect parameters set if it can run below 6,000 RPM

[jimskeet]

You can't run this spindle at 3000RPM you will damage the motor, they have a minimum RPM of 6,000, you have incorrect parameters set if it can run below 6,000 RPM

I was told that since the spindle is liquid cooled I can run it at lower rpm. Anyway I used that low rpm only to grind the inside of the spindles taper. Usually I run it around 330 and when I have to drop it I try to stay above 170. Only on some drilling operations I drop close to 100

[mactec54]

I was told that since the spindle is liquid cooled I can run it at lower rpm. Anyway I used that low rpm only to grind the inside of the spindles taper. Usually I run it around 330 and when I have to drop it I try to stay above 170. Only on some drilling operations I drop close to 100

You where told wrong, the water cooling only cools the outside of the spindle, you won't see how hot the inside gets until the smoke starts to come out

If you set you minimum speed parameter you won't have to worry about setting it to low

[coherent]

You where told wrong, the water cooling only cools the outside of the spindle, you won't see how hot the inside gets until the smoke starts to come out

If you set you minimum speed parameter you won't have to worry about setting it to low

Maybe this is why you are having bearing issues with your spindle?

[mactec54]

Maybe this is why you are having bearing issues with your spindle?

Yes over heating can cause Bearing problems

No Grounding of the spindle also will cause premature Bearing failure

Making heavy cuts in aluminum will also damage the bearing is these spindles

[jimskeet]

My bearings got damaged when the vfd faulted during a cut on aluminum and the spindle stopped without stopping axis motion. I was holding the pendant on my hand and hit stop right when I heard the spindle stopping but because the cut was a little heavy for this spindle it stopped so fast that it stopped and overloaded my X axis drive which in turn faulted too. After I reset the machine I heard the noise from the bearings.

[handlewanker]

Those darned high speed spindles...........more trouble than they're worth.......I can't imagine why anyone would run one for anything other than high speed engraving and carving but not low speed milling.......probably because that's all they've got.......a Jack of all trades is never the ideal.

Are the RPM values in post #15 for real????......even 10 X drilling with one at 1,000 rpm is asking a lot......HSS won't last long at that rate.

If I'm wrong on all counts, just ignore this post........I have a milling spindle on my mill driven by a separate 1 HP brushless motor and a 2 step pulley that is good for 7,000 rpm which in my opinion is the way to go.............I intend to reserve the high speed spindle for carving etc, in which mode it was designed to work best.

I'm stunned that a high speed spindle could run out so much that the taper needs re-machining.......you wouldn't want to have any backlash in the X axis when you do the tapering cut..........that would definitely have to be a lathe job.
Ian.