scott63 Posted December 23, 2007 Report Share Posted December 23, 2007 I have a JET 1236 PS belt drive lathe that is new to me, but built in 1984 and have a couple questions for anyone with the same/similar machine. The motor seems to vibrate a bit at higher RPMs, I've tried adjusting belt tension to no avail. In looking at the motor mounting I noticed a tapped hole on the side closest to the bed between the motor mounting holes on that side of the motor. I was able to thread a corse thread bolt into the hole, it's only about an inch deep though, and I wasn't sure if I should tighten in or not. I'm also wondering if there should be any rubber pads under the motor to dampen vibration. I've attached links to a couple pics which should be easier to understand than my ramblings. Thanks for any help........Scott http://i214.photobucket.com/albums/cc47/sc.../IMG_0270-1.jpg http://i214.photobucket.com/albums/cc47/sc...63/IMG_0273.jpg Link to comment Share on other sites More sharing options...
gun nutty Posted December 23, 2007 Report Share Posted December 23, 2007 That one bolt holding the motor up on the inboard side looks awful lonely. It doesn't look right, at least to me. Perhaps some blocks with shims would be better? Link to comment Share on other sites More sharing options...
tinkerfive Posted December 23, 2007 Report Share Posted December 23, 2007 I know that you said that you adjusted the tension. It looks to me as if that bolt raises the front end of the hinged motor mount plate. I can clearly see the hinge joint. I'd think that the bolt holds the hinged motor mount plate open against the belt tension. But then I do wear glasses. Tinker Link to comment Share on other sites More sharing options...
z1r Posted December 23, 2007 Report Share Posted December 23, 2007 That setup is very similar to my enco. Loosening that bolt adds tension to the drive belt. My enco also vibrates, my Clausing doesn't. Guess which one I use for putting a nice finish on things? I like the enco cuz I can cut metric threads with it. Link to comment Share on other sites More sharing options...
Limpid Lizard Posted December 23, 2007 Report Share Posted December 23, 2007 Does it vibrate with the chuck off? Do you have a spider? If so, have you removed it? These lathes are often equipped with unbalanced chucks and spiders. I do not know what RPM you are getting vibration at, but high speeds are the realm of collets. LL Link to comment Share on other sites More sharing options...
scott63 Posted December 23, 2007 Author Report Share Posted December 23, 2007 Does it vibrate with the chuck off? Do you have a spider? If so, have you removed it? These lathes are often equipped with unbalanced chucks and spiders. I do not know what RPM you are getting vibration at, but high speeds are the realm of collets. LL It is definitely smoother with collets, not too noticeable with my 3 jaw and most noticeable with my 4 jaw. So I'm trying to make the motor as smooth as possible before I try to balance the 4 jaw chuck, and since I haven't another lathe of this vintage to look at, I don't know if there is anything missing from the motor mounting assembly. To say the owners manual is brief would be a vast understatement, and it reads like a fortune cookie! Link to comment Share on other sites More sharing options...
scott63 Posted December 23, 2007 Author Report Share Posted December 23, 2007 It is definitely smoother with collets, not too noticeable with my 3 jaw and most noticeable with my 4 jaw. So I'm trying to make the motor as smooth as possible before I try to balance the 4 jaw chuck, and since I haven't another lathe of this vintage to look at, I don't know if there is anything missing from the motor mounting assembly. To say the owners manual is brief would be a vast understatement, and it reads like a fortune cookie! For those of you with belt driven lathes, what brand of belts do you use? It has been suggested elswhere to try changing the belts.......Scott Link to comment Share on other sites More sharing options...
ken98k Posted December 23, 2007 Report Share Posted December 23, 2007 You may have already tried this- Does the motor vibrate with the belt removed? Link to comment Share on other sites More sharing options...
donmarkey Posted December 23, 2007 Report Share Posted December 23, 2007 For those of you with belt driven lathes, what brand of belts do you use? It has been suggested elswhere to try changing the belts.......Scott I use those link belts on most my equipment, It did wonders for my tablesaw, it now passes the nickel test. I love them and you just buy them by the foot and you always have whatever size you need. -Don Link to comment Share on other sites More sharing options...
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