Another possible bearings question

[Bodger7]

Hi
I have got a Wivamac lathe that has not had much use but has been standing around unused for several years. I have used it quite a bit recently as I have been getting back into turning and it is causing me some concern. The issues are as follows:-
1. When spindle turning last night I made a partial cut with a parting tool but when I later cut down to the end of the cut I found that the original cut did not co-incide with the later one. In other words when I made the later cut, finishing with a scraper, I found that the parting tool cut was removed on part of the cylinder but not all of it. One cut seemed to be on a different radius to the other. I hope that that makes sense!!!
2. When using either a spindle gouge or a bowl gouge there is an unpleasant squealing noise when rubbing the bevel.
3. The motor seemed to get excessively hot after running for about an hour or so but it sounded OK.
4. When running the lathe at high speed (3000 rpm) there was a very noticeable vibration even though the wood had been cut to an even cylinder.

Does this sound like knackered bearings? My Wivamac handbook does give instructions for changing the bearings. Any suggestions would be very welcome. Thanks.

 

[kirso]

When the motor was hot was the bearing areas hot as well ?

If it was the headstock bearings putting excess load onto motor , I would have thought the bearings would be hot too.
It maybe that the motor bearings are at fault. You could remove the drive belt and run the motor on no load to check same. Or just free spin it and see if all ok.
If the bearing swap is an option, then I would do it anyway . Due to the couple of years it has been stood. The grease could have gone off or dried up.

 

[Bodger7]

Thanks for your reply Kirso but I don't know if the bearings area was hot as well. I will check when I next use the lathe but for the other reasons given by you I will probably change the bearings anyway. As matter of interest the lathe had been standing idle for about 10 years. I will run the motor without a load today and see whether it overheats then. I hope that that will tell me something.

 

[CHJ]

90% sure your problems are due to or are wood related.

Going back to an area of machined wood after a a period of time when the stresses in the wood have been released due to further material removal elswhere is almost certainly going to cause a surface concentricity problem.

This can also alter the balance of the piece due to varying densities of the wood.

Sympathetic vibration at various speeds/frequencies will occur as a result of the above and lathe speed needs adjusting to find the sweet spot that eliminates or reduces to a minimum this vibration. The chances of getting vibration free spinning at all speeds is remote.

How are you holding the piece, between standard centres? there is a very good possibility that the centre location points in the wood are migrating along the path of least resistance following the grain towards the perifery of the piece, causing prieviously turned areas to run out of true.

Squealing noise, what type of tailstock centre are you using?

Modern cheap and chearful (alluminium framed) motors often run at an uncomfortable hand heat level.

 

[stewart]

You might want to speak to Peter at Toolpost who are agents for Wivamac lathes.

 

[MusicMan]

+1 for wood-related as CHJ says.

When turning musical instruments, one has to complete a spindle cut and parting off in one session or it is likely to move if left for a few hours. Boxwood is pretty bad for this.

You might improve the vibration (if caused by wood density variations as CJH plausibly suggests) by using a fixed steady. But it is a good idea to check the no-load vibration and heating.

It might be bearings but they are robust things.

Keith