lathe vibrate at lower speed

[thorens]

Not knowing how much runout there is in the OD of the backplate I would take a guess and say it would have to be around 1mm or more to give any significant chance of vibration.

If as you say the backplate is 8mm larger than the chuck machine the backplate OD with the chuck attached,I wouldnt be removing or loosening the chuck seeing you have already set the chuck to be running .04mm.

I would turn the OD at around 150RPM with a tipped tool or your lowest RPM with HSS,feed slow.

done it and still have some vibration . however after mucking around a bit more on the chuck, it now runout down to 0.03mm

Peter

[pipeclay]

Is there still vibration either coming from the Headstock or spindle with the chuck removed?

If there still is vibration try removing one of the drive belts if there are 2,try taking a little tension off the drive belt/s,try putting a bit of rubber between the motor mount and lathe.

If there is still vibration present after removing the chuck,run the lathe through its speed range and see if the vibration stays uniform throughout the cycle.

Try putting your hand on the Headstock and then Tailstock whilst running and see if you can feel the vibration.

I still have a strong suspicion that either the Headstock Spindle bearings need adjusting or all of the Headstock bearings need replacing.

[eskimo]

have you checked the belt and tension?

[thorens]

have you checked the belt and tension?

yes i did but wouldn't tell what is the right tension.
is an inches of push in with your finger is ok for belt tension?
Peter

[thorens]

Is there still vibration either coming from the Headstock or spindle with the chuck removed?

If there still is vibration try removing one of the drive belts if there are 2,try taking a little tension off the drive belt/s,try putting a bit of rubber between the motor mount and lathe.

If there is still vibration present after removing the chuck,run the lathe through its speed range and see if the vibration stays uniform throughout the cycle.

Try putting your hand on the Headstock and then Tailstock whilst running and see if you can feel the vibration.

I still have a strong suspicion that either the Headstock Spindle bearings need adjusting or all of the Headstock bearings need replacing.

I will try again on the belt tension. the vibration mainly in the headstock not much feel in the tailstock.
don't really want to muck around on the headstock bearing thought
Peter

[azzrock]

bill maybe you should post a photo of your set up. just some history.
the lathe was vibration more that this. in the head stock one of the top
head stock gears was not fully engaging because of a cir clip positioned
in the wrong place after fixing this the vibration was a lot less pronounced. .
aaron

[azzrock]

there is a single drive belt tensioned right maybe on the tight side if any thing but id say ok

[Sterob]

Another source of some vibration are the drive belts, if the lathe has been sitting for a long time without use.
The belts get 'bumps' in them from sitting around the pulleys.
I fitted Link Belts to my AL-335 and it was significantly smoother.

[thorens]

it is a motor pulley that is slightly angled to the spindle pulley . align them straight was minimize the vibration to almost zero.
thanks Aaron. he is the one work this out.
thanks all .
Peter

[azzrock]

no problem happy to help any time.