Granville Lathe Pains

[ChadParticipant @chad]

Hello,

 

My Granville Senior lathe is giving me headaches. I am getting a strange vibration which is causing the motor to bob up & down. I checked the pulley on the motor shaft and found it to be out of round by 0.010″ and had the machinist at work verify this. Now that I have replaced the pulley the vibration is less severe, but still noticeable. There does not seem to be any play in the spindle, so I am at a bit of a loss of where to look next.

 

I should probably tear the thing apart and rebuild it, but now is not exactly the season for that type of activity since my little heater will only keep my shop at 5 degree C.

 

Thanks,

 

Chad

Edited By Chad on 30/01/2010 04:54:05

[ChadParticipant @chad]

Motor vibration problems

[keithmartParticipant @keithmart]

hi

Have you run the motor without the belt on? 

Does it vibrate then?

If you remove the pulley and run the motor, does it still vibrate?

regards

Keith

Leeds UK

[John CParticipant @johnc47954]

I’m with Keith on this one.  If the drive belt has ‘set’ the tension will change as it moves, causing the motor to move against the belt tensioner in response. This may be your problem.

John

[mgjParticipant @mgj]

Countershaft bearings? Motor bearings? Is it noisy? Is this a new phenomenon?

 

Try turning the motor in its bearing housings. Sometimes when plain bearings are worn in one place from belt tension, you get a reduction by bringing a less worn bit into line. Its not a cure but it does help diagnose. 

 

The other thing is to measure belt thickness. If you have a thinned patch from slippage at some stage, or some other kind of oddball wear, its going to bounce in and out of the pulleys and alter local tension..

 

[ChadParticipant @chad]

Thanks for the pointers. I think you have put me on the right track, since after carefully inspecting the belts, I can see that the belt running to the spindle seems to be slightly frayed on the left hand side. I am going to replace the belt and see if that corrects the problem. Also, I will try running the motor disconnected from the lathe and check the results.

 

I will let you know what I find and post pictures of my lathe soon. It really needs to be stripped down, since the last owner used it almost exclusively for turning wood and it is full of wood flour.

 

Thanks again,

 

Chad

 

[KWILParticipant @kwil]

I had the same problem with a belt fraying, actually breaking up at the end of the lap joint.

[mgjParticipant @mgj]

Might be worth just checking that the pulleys align with each other? A misalignment there would cause one side to rub.

[Ian S CParticipant @iansc]

meyrick, thats just what I was going to say. As the lathes been used on wood, check the bearings, wood is like blotting paper were oil is, so they could be dry and packed with wood dust. Had a look on Google, it looks a nice little lathe, good luck. Ian S C

[ChadParticipant @chad]

I have posted pictures of the lathe in question if anybody is interested in having a look at her. Once I get the lathe running properly, I think I will be happy with the investment, but right now it is kind of frustrating.

[Graham FlavellParticipant @grahamflavell13482]

Hi

Interested to see the photographs. I have a Granville Senior which I have owned for about 20 years. In your photographs I can not see the countershaft locking and tensioning lever which sits between the countershaft frame and the headstock. Could this be one of your problems? There is a clear picture of the lever location on Tony Griffiths site lathes.co.uk. in the Granvile pages.

Regards,

Graham

[ChadParticipant @chad]

Graham,

 

I am posting more detailed photos of my lathe. In them, you will see the broken bracket where I assume the locking lever should be??? Could you please post photos of your lathe so that I can get an idea of how to repair mine? I would appreciate it very much!

 

Thanks,

 

Chad

[Graham FlavellParticipant @grahamflavell13482]

Hi,

OK I will go down to the workshop this weekend and see if I can get some useful photographs.

 

Regards,

Graham

[Graham FlavellParticipant @grahamflavell13482]

Hi,

Tried to take some pictures this afternoon. It is very difficult to get a clear picture. I took the lever off eventually. It is held into the cast lug on the headstock with a 3/8 Whit 3in LG Bolt locked off with a nut. The lever casting has a domed nut screwed into it to give some adjustment. I hope the pictures help.

Regards,

Graham

[ChadParticipant @chad]

Hi Graham,

 

Thanks very much for the pictures, they are immensely helpful. Once I get the casting fixed I should be able to reproduce the locking mechanism.

 

Cheers,

 

Chad

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