Spindle Bearings Gone? Nice broken tool picture for the vultures....

[Rick_H]

Well just to set the story, my Dad works here at the shop on the Hurco VM10's and has been a little care-less.....

We use a 'cap' over the workpeice (all aluminium) to keep it flat, this is added when the machine comes to a stop with an M0 half way through, as you can guess this cap should not be there at the start of the programme (which he re-loaded without removing the finished work) and the 50mm face-mill plunged in at 7000rpm on rapid, it blew to bits as you can see in the picture before interpolating the 'cap' for a little while until i could run over and mash the stop button (It didnt overload and alarm out suprisingly)

Reset the stop, removed the massacred tool and started the spindle at 1000rpm and as i turned up the RPM I was met with a different noise to usual. The spindle now has a 'wine' that gets louder and higher pitched as the RPM increases.

I have checked spindle runout at the taper and it is well within spec, tools change as they should and I have had the belt cover off and nothing looks strange there, there is no rumbling or metalic noise and the spindle feels normal when turning by hand.

I will be putting a call in tomorrow to get a tech out, but in the meantime can anybody give me hope that i dont need to replace the spindle bearings in a machine that is less than 2 years old with low hours? Or is it wishfull thinking and the old man is in serious S**T!

 

[Sauerkraut]

Sorry;

My guess is Brinelled bearings..

 

[chip_maker]

Does it get hot?

you already checked run out and it looks good.

I'd save my money and run it till (if/when) it shows signs of it being damaged (excessive heat, poor finish etc).

 

[Captdave]

I would take another look at the belts before I call in a tech. You almost have to remove them to get a really good look but I would put money on the belts are chewed up from the spindle stopping.

We have a 2010 VM-10 here and have had to replace the belts more then once, its a pretty tough machine but this maybe one of the times you'll be glad you don't have too much HP. I would run it and check for heat on the bearings, if nothing then after a few hours running it will quiet down. If you need the instructions on how to orient the spindle if you have removed the belts just send a PM with your email address.

 

[Rick_H]

Thanks for the replies guys and for the help there Dave, much appreciated.

I did check for heat and it seemed fine, though we do have the optional chiller - As i say there is no rumble or metalic sound and it feels good, runout is also perfect.

The belts do look 'OK' visually and the spindle didnt come to a stop until the emergency was pushed, I imagine the tool breaking up gave it enough room to keep going.

I will order the belts and spindle orient procedure from Hurco tomorrow - it is worth a shot, at worst I have the belts I would need if it was the bearings anyway.

Thank you for the offer of help regarding orienting the spindle, I will get in touch if I get too stuck!

 

[RevetsP]

I have not seen the insides of a hurco spindle, though I'd imagine there is a labyrinth ring/seal? Maybe that got dingged up and is rubbing, pretty common on smaller lathes and such. Depending on how the spindle cartridge sits in there... maybe you can re-seat it??? (wishful thinking) If nothing is messed up (too bad) maybe try to break-in and run-in the spindle again a watch for heat/noise and check runout again. Check the belt tension? is there a separate encoder?

Are you sure its the spindle? how about spindle motor? or a piece of hose or cable that is rubbing? Maybe those are silly... but cheaper to find out yourself rather than have a service tech find out a conduit was rubbing... :O

 

[charlie gary]

Not to be an ass, but have you taken into consideration you may be hearing something because you expect to hear it?

 

[Rick_H]

Not to be an ass, but have you taken into consideration you may be hearing something because you expect to hear it?

Your not being an ass at all, I know what you mean but it is several times louder than before and does 'whine' now (like a bad trans bearing in a car) there were 3 people here at the time and we all know these machines well ( there is an identical one 5 foot away from it to compare to) - I would like it to be paranoia but not this time - thats not saying it isnt the belts or something much less serious though.

 

[DavidScott]

It seems to me that spindles have nine lives. You just used up a few, time will tell how many. Try using it gently and go from there, keeping a close eye on it. It sounds like it will still work fine but may make a little noise. Noise doesn't mean it is dead but it does mean you better start saving up. It could be days or years, I would guess you will still get plenty of use out of it. Keep an eye on the surface finish on the bottom of pockets, this is a good indicator of when you lose the preload.

Same thing happened to me a about a year ago, wasn't even a bad crash. Spindle started making a distinct whine. Just used it and a week later it went away. A month ago it started again and is slowly getting worse. It is still working fine but a rebuild is on the horizon.

 

[Richard King]

It's a shame but accidents happen. Run down to an auto parts store and buy a http://www.amazon.com/Lisle-52500-Mechanics-Stethoscope/dp/B0002SQYSM
and put it on the headstock casting and listen for the loudest spot. This will help to detect if the noise is from the top or bottom of the head. In the old days we would also use a hollow pipe of long screwdriver pressed against your ear and the headstock, but the stethoscope is so much better. Many times when a bearing is shot you can really hear a bad bearing when you shut off the spindle and let it coast to stop. I am not sure you can shut off the brake or not. From a simple drawing I saw online it looks like the spindle is a cartridge so if the noise is n the spindle, I would suggest buying a new cartridge from the factory. Rich

 

[Rick_H]

Well the tech has been out for a look (Independent, not Hurco) and is thinking along the lines of CaptDave and that it is a belt problem (stretch in one area or similar) - I have too much work on to spend time with this at the moment.

We have new belts on order which he will put on and orient the spindle, he says it would be 'unusual' to hear bearing failure in this manner which is at least hopeful and that I they are bad we should run them until it causes a problem.

So hopefully we have a bit of a drama here and not a crisis, and dad still has a job ;-)

Thank you for the help and comments guys. Rick

 

[scadvice]

Hopefully, its only a few hundred euro's and a reminder to spend a few minutes proofing out a program when making changes.

 

[Rick_H]

Hopefully, its only a few hundred euro's and a reminder to spend a few minutes proofing out a program when making changes.

I do hope so - Though this time it was total operator error, he forgot to remove the part that had been finished after loading OP1's material - he then re-loaded the programme 2 rather than 1 hence the crash, nothing that could be done about it and an honest mistake. We have been running the same part with sight variations on this machine since Christmas so in terms of programming it is fine... just one of those things.

 

[706jim]

I've had an operator crash a face mill into a steel plate hard enough to weld the cutter body to the material.

Spindle bearings survived ok.

I think it helps that you hit aluminum although you wouldn't know it from that face mill!

 

[Captdave]

The belts on that machine are pretty small so it doesn't take much to trash them which is a good thing. We have a couple of extra sets in the electrical cabinet for when their needed.

The boy can change the belts and reset the orient parameter in about an hour. Order an extra set while your at it, their cheaper that way.

 

[scadvice]

I do hope so - Though this time it was total operator error, he forgot to remove the part that had been finished after loading OP1's material - he then re-loaded the programme 2 rather than 1 hence the crash, nothing that could be done about it and an honest mistake. We have been running the same part with sight variations on this machine since Christmas so in terms of programming it is fine... just one of those things.

Yep...that can be a problem...

However, I have written in code that if the op is wrong there is a test move that hits a 3 inch wide piece of 1/8 aluminum sticking up above the part and to the side, it makes one hell of a racket when the face mill cuts into that little piece of sheet first. If its the right op it misses....It does add around 10 sec or so but safe.

Depending on your setup that may or may not work.