[danielcoyle]

Hello - I have a water cooled 4.5kw, 220V spindle from my JCUT 25 S machine that I feel has significant spindle bearing wear. I am not a very experienced machinist. The spindle used to turn quietly when spun by hand and when spinning down to a stop but now there is a clear constant noise the accompanies these movements. I have had the spindle for less than a year and use it with a relatively long tool to hog out hard and soft wood. At times the water pump that was supplied with the machine has turned off and the spindle has gotten very hot and I feel this is the most likely culprit.

What can I do here? Is my diagnosis correct and what does this mean for the spindle and continuing to use it as is? What would it take to fix this/replace the bearings? Difficult? Expensive?

Any info would likely make a world of difference for me as I am starting from close to zero experience.

Thanks

Dan

[danielcoyle]

I have added some pics here of the spindles I am using. i spoke with a guy on the phone who said he would charge me around $2500-$3000 to replace the bearings and re-balance the spindle. He didn't see the spindles. Is that for real? Attachment 233726

[mactec54]

danielcoyle

I'm surprised that it is still running at all, after running it with no water, Your best bet would be to get another spindle, as I'm sure the stator winding insulation,has been damaged, from the over heating, the Bearings may be on the way out, & are easy to replace, US made Bearing for your spindle are spendy,so it is best to try & get bearings from China, or the manufacture of the spindle, I have rebuilt some of these spindles,they don't cost any were near the number that you posted, but if you have to use US made bearings, it could cost as much as a new replacement spindle form China

I hope you have replaced the water pump,with a good quality pump, so this does not happen again

[danielcoyle]

thanks mactec. i don't really know what stators are or why the insulation for them is important so i had to google it. I plan to take the spindle apart and inspect, take some photos. it would cost around $1400 to replace the spindle from china it looks like just doing a quick internet search, haven't heard back yet from the manufacturer. it still worked when i took it off but i just don't know how to tell if it is worn but still has some life left or if i am about to do irreparable harm to it by continuing to use it. that's just a response to let you know where i am at as far as knowledge about this. i will send pics along today.

[mactec54]

danielcoyle

You need the correct custom tools to take it apart, if you damage any parts, taking it apart with the wrong tools, it will be put it out of balance, which you don't want to do, is your spindle a 3 bearings or 4 bearing spindle, see if the manufacture will send you a drawing of the spindle showing the bearing assembly, Bearing numbers

[danielcoyle]

Ok. Thanks again. Took me a while to get these pics and video up.

I guess I am wondering now what type of tools are needed or what type of shop I could go to to have this done? I have asked the manufacturer but no word yet. Here are pics of the disassembled spindle and what I think is the stator. Does it seem like there is damage from looking at it? what would i look for?Attachment 233950Attachment 233952Attachment 233954Attachment 233956Attachment 233958Attachment 233960Attachment 233962

Here is a video where i try to demonstrate the noise the bearing is making amongst other things.

any thoughts on what next to do? thanks mactec!

[mactec54]

danielcoyle

I think you got lucky, It was close though, you can see were the heat mark is on the rotor, just a little bit more, & the stator would of been toast, the front bearings, sound like all the lube has run out,this happens a lot with grease filled high speed spindles, Be very careful with the front Nut, this is were you need the correct wrench to take that center Nut off, this can not be damaged, most of them are made of aluminum, so are easy to damage

[danielcoyle]

thanks again. this is so helpful. i had been avoiding this project for months imagining it being terrible.
i took another shorter video of the spindle body and some questions about it. It looks like i will need a puller to get the front bearings off? then some sort of press to get them back on of course. finally, is it normal for the bearings to lose grease like that? is it because i ran it hot? are there preferred bearings to use?

[mactec54]

danielcoyle

The front & back nut, is the part with the holes in the front, you have to make a steel wrench with the pins in,to match the Holes in the nut, the Bearing will not be pressed on, they will slide, off once you undo the front nut, the back Nut most likely has a left hand thread, you can do this your self, with a little care, note the Bearings, do they have a different color seal on the front & back of the Bearing,any arrows or lines marked on the Bearing outside race take photos of this or keep note's of what way round the Bearings are

You can buy a Pin wrench, but they are not so good for this job, & in most cases it will damage The Nut, which you don't want to do

[mactec54]

danielcoyle

This is the type of wrench you need to take the front nut off the spindle, the wrench needs to match the hole pattern in the (2) nuts, it wants to be a good fit on the pins, the tighter the fit the less damage it/ you will do, if the Nuts gets damaged, they will have to be remade, as this is part of the spindle balance

The cracks you see at the ends of the rotor, are nothing to worry about, most of these rotors are like this from the manufacture

[danielcoyle]

Awesome. Thanks so much. Will take your instructions. This is such a relief and you made it easy.

I will order some new bearings from the chinese.

Have a great weekend mactec!

[johnsattuk]

Needle rollers make good strong pins

[mactec54]

danielcoyle

Before you take the nuts off, there are Balancing pieces, at each end of the rotor, they are the pieces that look like a spacer/washer, they have a grove in the center, Just in case they are loose on the shaft, you need to mark there position, to make sure that there position does not move,if they move the Balance will be messed up

[danielcoyle]

ok. thanks again. will look for these but worried i already moved them? i haven't taken the nuts off yet though.

[mactec54]

ok. thanks again. will look for these but worried i already moved them? i haven't taken the nuts off yet though.

With the Nuts still clamped I doubt that you could move them, they may not even move when you undo the Nuts, it was just a heads up, something to be aware of, mark there position, with the Rotor

This is not the ones between the bearings, they are at each end of the Rotor only, they have some drilled holes in the outside face these were done for the Balancing

[fixtureman1]

When you do go to put it together put the rotor in a freezer and warm the bearings that way they should slip right on.