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Tighten the gibs.
-
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Cross slide handle misbehavior
- Thread starter AllenV
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- Nov 14, 2020
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Don't tighten your gibs.
Tighten the nut to screw, if the weight of the handwheel is enough to cause the screw to rotate the free play out the nut is not tight enough on the screw and you do have backlash in your screw and nut assembly.
Think about it......
Tighten the nut to screw, if the weight of the handwheel is enough to cause the screw to rotate the free play out the nut is not tight enough on the screw and you do have backlash in your screw and nut assembly.
Think about it......
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- Dec 25, 2017
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Thank you, that was a productive set of responses. Please forgive me for not thanking each of you individually.
Seems to me the best path is to do both, tighten the anti-backlash nut and the gibs.
It absolutely makes sense that an anti-back lash nut that will allow gravity, the weakest of the fundamental forces, to rotate a handle is a nut that is not tight enough. I had adjusted the backlash to 0.009” simply because others had indicated that was a good number. But, if friction at that setting is a low as this one, then certainly it can be tighter without generating excess screw wear. I will experiment with tightening it until the handle free-fall stops.
I will adjust the gibs because no one on this continent has ever touched the gibs on this machine. It is well past time.
I have project coming up turning some 2” round stock. I will do the adjustments, then the project, and report back.
Seems to me the best path is to do both, tighten the anti-backlash nut and the gibs.
It absolutely makes sense that an anti-back lash nut that will allow gravity, the weakest of the fundamental forces, to rotate a handle is a nut that is not tight enough. I had adjusted the backlash to 0.009” simply because others had indicated that was a good number. But, if friction at that setting is a low as this one, then certainly it can be tighter without generating excess screw wear. I will experiment with tightening it until the handle free-fall stops.
I will adjust the gibs because no one on this continent has ever touched the gibs on this machine. It is well past time.
I have project coming up turning some 2” round stock. I will do the adjustments, then the project, and report back.
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- Apr 30, 2015
- Messages
- 12,451
Usually a machine will have enough friction in the cross slide screw
that this problem never shows up- going off on a wild gib-chase won't solve it
Snugging up the nut is the way to go IMO, plus some heavy grease
that this problem never shows up- going off on a wild gib-chase won't solve it
Snugging up the nut is the way to go IMO, plus some heavy grease
Last edited:
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- Feb 1, 2015
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Tightening the backlash adjustment on the lead screw nut isn't the way to solve this problem. The resultant friction required to to stop inadvertent rotation of the crank will result in increased wear on both the nut and the lead screw. Adjust the lead screw nut to minimize backlash. Also check the preload on the thrust bearing and adjust to minimize backlash. Adjust the gibs so there is a very slight drag as evidenced by a rise in force required to move the cross slide.
Minimizing backlash will minimize the momentum as the crank rides over center. Adjusting the gibs will provide enough friction to overcome any remaining gravitational force. An added benefit of adjusting the cross slide gibs is that you will decrease play in the z axis as well as the vertical plane,increasing rigidity and accuracy.
Minimizing backlash will minimize the momentum as the crank rides over center. Adjusting the gibs will provide enough friction to overcome any remaining gravitational force. An added benefit of adjusting the cross slide gibs is that you will decrease play in the z axis as well as the vertical plane,increasing rigidity and accuracy.
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- Nov 14, 2020
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Since you bought this machine new in 2006 and you probably haven't abused it I doubt the gib needs much adjustment.
Try adjusting the cross slide nut,are a cut or two before jumping on adjusting the gib.
Like a math problem, only change one variable at a time.
It can be tough to feel the screw adjustment if you have already adjusted the gib or vice versa.
Try adjusting the cross slide nut,are a cut or two before jumping on adjusting the gib.
Like a math problem, only change one variable at a time.
It can be tough to feel the screw adjustment if you have already adjusted the gib or vice versa.
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- Dec 12, 2016
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- 529
I balanced my cross slide and carriage hand wheels.
On the slide, I made a new aluminum handle and added a steel 1/2 height handle/weight on the other side.
The carriage wheel got an aluminum handle and a series of lightening holes on the back near the handle. A series of holes on the opposite side were filled with lead and the holes near the handle were filled with foam. A skim coat of epoxy encapsulated everything.
On the slide, I made a new aluminum handle and added a steel 1/2 height handle/weight on the other side.
The carriage wheel got an aluminum handle and a series of lightening holes on the back near the handle. A series of holes on the opposite side were filled with lead and the holes near the handle were filled with foam. A skim coat of epoxy encapsulated everything.
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- Dec 25, 2017
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- 167
As I was waking up this AM I was mentally working on this. Having a look at the condition of the "bearing" nut holding the screw to the bearing makes sense. (This is not the anti backlash nut). Getting at that nut involves removing the handle. Pulling the handle will require that I make some sort of small roll-pin press. Once the handle is off, I may as well drill a hole in it to provision for balance weights or a second "stick" handle.
All of this stuff is is simple and no-cost. I am just working thru an order of operations. I think this is it:
1 - inspect the bearing nut. Adjust if warranted. Provision handle for balancing
2 - test cross slide operation
2- measure the gib freeplay. Adjust if warranted
3- test the lathe cross slide operation. Is it fixed?
4 - adjust the anti back lash nut to pickup a bit of friction, if warranted
5 - balance the handle
I am leaving balancing the handle to last as I'd like to see what the three adjustments achieve.
All of this stuff is is simple and no-cost. I am just working thru an order of operations. I think this is it:
1 - inspect the bearing nut. Adjust if warranted. Provision handle for balancing
2 - test cross slide operation
2- measure the gib freeplay. Adjust if warranted
3- test the lathe cross slide operation. Is it fixed?
4 - adjust the anti back lash nut to pickup a bit of friction, if warranted
5 - balance the handle
I am leaving balancing the handle to last as I'd like to see what the three adjustments achieve.
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