Thread: lathe sprindle temperature

Originally Posted by thorens

I just wondering how warm the spindle is consider normal ? my lathe spindle get quite warm for the touch after about 15 mins of turning when touching the chuck.
thanks
peter

Peter , it is normal to feel some heat there. I would not worry about it unless the chuck appears to be labouring or binding to some degree . If you disengage the drive , the chuck should turn without too much force. If it is not easy to turn, then something is too tight .

What type of lathe is it ..plain or roller bearings ? MIKE

Hi Peter,
The chuck gets hot?
Whats it like around the bearings?
What sort of lathe? Is it new?

Stuart

There has been quite a bit of discussion about this on other forums, especially PM. My understanding is some temp rise is desirable, but if it's too hot to hold your hand on it's too hot and indicates an issue with your bearings - either a preload or a lube problem. Hopefully Machtool Phil will clarify this. But I should ask - what sort of lathe, what sort of condition, what sort of bearings, what sort of speeds?

The lathe that you have shouldnt really be getting the chuck Hot,I realise you havent said Hot but warm.
Warm is ok as some heat will be transfered along the spindle to the chuck,this warmth should not be such that it becomes uncomfortable for you to have your hand resting on it.

The lathe in question is one of the type that are roller bearing,with vee belt speed change,lift up lid for belt change,2 sight glasses for bearing oil.

Originally Posted by pipeclay

The lathe in question is one of the type that are roller bearing,with vee belt speed change,lift up lid for belt change,2 sight glasses for bearing oil.

Thanks .
yes I think you know the lathe I'm talking about. i concern a little because the chuck when turn by hand do have aquite a bit of resistance so I thought there might be some thing's to do with the spridle bearing.

do you know how to adjust a pre-load on this lathe ? I have the manual but it didn't say anything's about it.

Cheers all
Peter

I went down the taper bearing track after buying new bearings for my mill spindles. Most has been covered above but I will just add that the bearing temperature should level off after it has warmed up and not keep climbing, if it does your preload is too high.
Like Pipeclay said you should be able to keep your hand on it, whether it is run for 15 minutes or 1 hour.
If you need help with doing the preload, Grizzly online lathe manuals have the procedure.

Dave

How tight are your drive belts?
Is the chuck easier to rotate when the belts are loose?
Is back gear engaged when you have been trying to rotate the chuck?
Is the same resistance felt when the lathe is cold?

The quick and dirty method I've used in the past on a similar lathe (and inspired by Ford, who at one stage used something similar for wheel bearing adjustment I was told). Proper preloading usually requires all sorts of technical bits (shims, gauges etc)
First, the spindle and bearings need to be at operating temperature - usually this means running the lathe for 20 to 30 minutes.
Tighten up the bearings until they feel too firm (you could well be at this stage now). Typical symptoms are that they feel tight, stiff to turn and a bit lumpy. You are not trying to lock up the spindle here, just tighten things up to lose any slack or backlash. Rotate the spindle by hand a few turns just to make sure that everything is sitting right and bedded down.
Now, slacken the preload nuts off until they are loose and then just lightly nip them up then lock in position.
So to summarise, you've over tightened to remove any slop then you back off and nip up just enough hold that slop free condition.

(I'll just go and put on my flame proof suit now...)

Michael

I found with my tapered roller bearings that if you want to loosen the preload, after loosening of the preload nut, you also have to give the spindle a tap at the end with a soft mallet. Otherwise it will not noticeably loosen off.

I also noticed that when first replaced, they ran a little warm for about an hour and then settled down. When I mean warm I mean warm to the touch, not hot. About 15 - 20 deg above ambient using a non contact thermometer.

My 2 cents worth.

Simon

Originally Posted by pipeclay

How tight are your drive belts?
Is the chuck easier to rotate when the belts are loose?
Is back gear engaged when you have been trying to rotate the chuck?
Is the same resistance felt when the lathe is cold?

1/the Belt is a bit lose at least an inch when push down by finger .
2/same resistance when the belt is losen .
3/same if the back gear engaged or not . the chuck rotation is the same.
4/same when it cold and when it get hot.
regards
Peter