Cross Slide Handle Falling When Turning

[737mechanic]

My cross slide handle/wheel will rotate and fall down causing the cutter to back out of the work piece when I am turning. This happens when the handle is on the left side of the wheel.

I know the reason it does this is because it is not a balanced wheel/handle like my older atlas was but I was wondering what people have been doing to deal with this problem.

Thought about either modifying or purchasing a balanced handle/wheel.

 

[mikey]

Have you adjusted for backlash on the cross slide screw?

 

[higgite]

Further to Mikey’s question, is the tool actually backing away from the work piece or is the hand wheel/dial just backing off by an amount equal to the backlash in the cross slide screw without moving the tool?

You didn’t mention what lathe you have, but the two I have owned have a nut under the slide to adjust backlash and hold tension on the screw.

Tom

 

[737mechanic]

Yes the handle is falling because of a slight amount of backlash but if I tighten the lead nut to put tension on the lead screw that will fix the handle falling problem but it will also wear the lead screw prematurely and will only be temporary. My atlas had much more backlash than my G4003G and the handle would stay put because it was a balanced handle. I was thinking about buying a balanced handle and bolting on it.

 

[JimDawson]

You could make a little friction thingy (very technical term ) out of a couple fiber washers and a wave washer. Maybe a little bit of blue Loc-Tite on the nut to hold everything at the correct tension.

 

[737mechanic]

I thought there might already be some kind of friction washer of some type in the handle itself but I have not looked hard enough yet. I was also thinking of unscrewing the handle from the wheel and weighing it and machining a pocket 180 degrees on the wheel and melting lead in it weighing the same to balance it.

 

[737mechanic]

I was looking at installing something like this old school balanced crank handle.

http://workholdingcomponents.morton...dles/balanced-crank-handles-revolving-fixed-?

 

[mikey]

Yes the handle is falling because of a slight amount of backlash but if I tighten the lead nut to put tension on the lead screw that will fix the handle falling problem but it will also wear the lead screw prematurely and will only be temporary.

I think the excessive backlash is going to muck up your leadscrew more than adjusting it properly will. When you just take up the play you are bringing the flanks of the threads on the screw and nut into contact, which is how they should run. If your leadscrew nut has a split at the rear then adjusting it until excessive play is removed is something you might consider doing.

I'm not disagreeing that the handle is off balance though; all handles with a knob are.

 

[Tony Wells]

Your gibs are too loose if it won't hold position, unless you are running ballscrews. Many lathes do not have, nor rely on, balanced handwheels.

 

[737mechanic]

There is about .006 backlash in the cross slide lead screw and I don't really consider that excessive and shouldn't make the handle fall under its own weight. The lathe is only 1 year old and has done this since day one. I have just read a thread somewhere else where they adjusted the cross slide handle spanner nut and eliminated the falling under its own weight so once I get home and have some time I am going to look into that. The manual doesn't mention any adjustment on the handle that I could find other than adjusting the lead screw split nut. When you look at any old lathe ie: southbend, atlas, logan, clausing the cross slide handle is always a balanced handle I assume so it wouldn't have this very problem. My atlas was 75 years old and had about .015 backlash and I never had this problem.