Author Topic: Droning Grad  (Read 4722 times)

Offline ChrisF

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Droning Grad
« on: February 04, 2016, 11:19:10 AM »
My graduate has developed a drone..... you can hear it here if you're interested ==> https://youtu.be/WaprRO4yCL4

It comes and goes, particularly when I increase the speed.  It's accompanied by a faint but distinct high frequency vibration that can be felt through the tool rest.  It's properly, possibly overly, greased at both ends of the shaft.

** Full Disclosure **  The chuck has become stuck on.....I can't shift it.  I have been.....robust, shall we say, in trying to unscrew it, with no luck.  This drone started subsequent to these efforts.

Any thoughts/advice very gratefully received.

Offline Paul Hannaby

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Re: Droning Grad
« Reply #1 on: February 04, 2016, 11:41:42 AM »
No idea about the droning other than could you have ejected or disturbed the bearing lubrication? The way I free a stuck chuck is to open the jaws a little to allow a suitable metal bar (large screwdriver, prybar etc.) to be placed across them to act as a lever, then lock the spindle, put some pressure on the bar and if necessary give it a tap with a hammer.

Offline The Bowler Hatted Turner

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Re: Droning Grad
« Reply #2 on: February 04, 2016, 01:40:48 PM »
Chris I agree with Paul's method of removing the chuck but I tend to use a really long piece of wood in the jaws to increase the leverage rather than tapping with a hammer. The droning you can hear appears to be the bearings having worn and trying to dislodge your chuck may have been the final straw for them. There is a company that you can get them from but I just removed mine and took them to an agricultural machinery supplier and they had them on the shelf. If you need any advice on removing/replacing them PM me.

Offline ChrisF

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Re: Droning Grad
« Reply #3 on: February 04, 2016, 03:16:11 PM »
Thanks guys.  I'd tried a 12" bar to get the chuck to move with no luck.  In the end I resorted to an axe........ ;D  No, I really did.....the problem I was having was getting a long enough lever that was thin enough to fit between the jaws.  In the end I went with pen jaws (only 2 so much more room and quite deep) and the fibreglass handle of my felling axe as a lever.  I had to put pretty much all of 16st on it and bounce a little but it did the trick.

Just looked up the bearings....I was worried it'd be an expensive job but it seems not.  Although.....LRE are twice the price of specialised bearing suppliers......is there anything to watch out for?
« Last Edit: February 05, 2016, 01:34:03 PM by ChrisF »

Offline Mark Hancock

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Re: Droning Grad
« Reply #4 on: February 05, 2016, 09:57:47 AM »
Chris

In future put a leather washer or something similar on the headstock spindle before putting the chuck on. It makes life a lot easier.  :)

Offline The Bowler Hatted Turner

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Re: Droning Grad
« Reply #5 on: February 05, 2016, 12:34:50 PM »
I agree with Mark's post, on my Graduate I have made a washer from thin gasket material but the other thing is take care not to "spin" the chuck on, hand tight is tight enough if your lathe is revolving in the correct direction. Something you may want to consider is changing the drive belt at the same time.

Offline Nick Simpson

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Re: Droning Grad
« Reply #6 on: February 05, 2016, 01:28:11 PM »
You'll find nylon washers 1 1/4" or 1 1/2" on the plumbing shelves of your local hardware store.
Regards
Nick
See me at Boglecraft  https://www.Boglecraft.co.uk

Offline ChrisF

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Re: Droning Grad
« Reply #7 on: February 06, 2016, 08:51:03 AM »
Thanks for the advice guys, much appreciated.  Bearings are on the way so should all be hunky dory soon  ;D

Offline Nick Simpson

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Re: Droning Grad
« Reply #8 on: February 12, 2016, 10:43:03 AM »
As luck ??? would have it my Graduate started to 'drone' 3 days ago. This was sort of speed dependant. No rumbling when turned by hand and none up to about 800 rpm then went again at about 1800 rpm.
I phoned a knowledgeable friend who suggested slackening the 2 spacer grub screws and running & retightening. This narrowed the drone range to 1200 - 1450. I then removed the pulley grub screw and found that it was no longer centred on the dimple on the shaft. After re-centering this and retightening all has run ok for 3 days fairly hard work.

No need for new bearings thank goodness.
Regards
Nick
See me at Boglecraft  https://www.Boglecraft.co.uk

Offline ChrisF

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Re: Droning Grad
« Reply #9 on: February 12, 2016, 10:58:30 AM »
Well.....ordered new bearings and whilst waiting for them to arrive took friends advice, cleaned up the old grease around the housing, regreased, checked the belt alignment and a few other little bits, none of which appeared to make any difference.  Left it overnight and the next day it was all fine again.  No drone, no rumble, no problem at all.  ???

So, all happy and a new set of bearings sitting on the shelf ready for when they go for real  ;D