Help with adjusting LMS 5200 lathe

C

Ckormann

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Hi all,

I am new to machining and recently purchased an LMS 5200 lathe. I am having a difficult time adjusting the cross slide and the compound.

I am struggling to get the cross slide to move freely but be tight enough that it does not lift, for example, on a facing cut. I have the same issue with back lash. I have to make it pretty tight to remove the backlash, but then there is too much resistance when trying to move the cross slide.

I also have a back lash type behavior with the compound, but it is not back lash in the true sense. It is caused by the way the compound lead screw is held in place. There is about 20 thousands of play that the lead screw has with the bushing (for lack of the proper word to describe it) that holds the lead screw in place.

If anyone has experience with the LMS 5200 I would greatly appreciate your advice.

Thank you,
Chris
 
I'm not familliar with that model, but a lot of things are common between different lathes. One thing I can tell you is that you don't address backlash by tightening your gibs. The issue with your compound could be as simple as tightening the nuts at the handle to pull the slop out of it. Or it may have a worn screw and nut. Is it a used machine?
 
Thank you for responding. I didn't mean to imply I was trying to resolve back lash by adjusting the gibs. I should have been clearer about that. What I was trying to say was that in adjusting the gibs and the set screws for backlash, I can get the cross slide to be tight to the dovetail and still move easily, or I can get rid of back lash and have the cross slide still move easly. But I have been unable to have the cross slide tight to the dovetail and get rid of back lash and still move easily. I hope that makes sense.

Also, It is a new lathe.

Chris
 
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Was it built crooked? It sounds like your crosslide screw is binding.
 
It is just a customized Sieg, same as the one sold at harbor freight. I have a 7x16 from Harbor Freight that started life as a 7x10. I have extensively modified it mostly with LMS parts. The 5200 is a much higher end lathe though. When new the cross slide and compound are difficult to get adjusted until they wear in a little. I use a grease containing 65% molybdenum that can really help out but it is expensive. The grease is available on Amazon and Ebay. I use it on my rifle bolt lugs where it works like magic. You will most likely need to have a bit more drag on the cross slide and compound than you'd like until you use it enough to get the gibs and slides to wear in. The moly grease really helps on the cross slide screw where it goes into the cross slide. You will never get rid of all the backlash. You adjust for best available backlash and least drag and then use it. As it wears in you can readjust and eventually it will be pretty good. LMS sells brass gibs and they might help a bit. Also you could call LMS and ask for their suggestions. They are a great bunch of people.

Some more info at:
http://www.mini-lathe.com/
Roy
 
The cross slide and compound slide on these lathes(when new) are a little too finicky in my opinion but it doesn't mean you can not achieve the smoothe performance you're looking for,it takes a few sessions of fiddling with them to reach your goal.

I took apart both slides and cleaned them thoroughly, sanded the gibs a bit to get rid of a couple of high spots, greased everything and reassembled them ,then started to adjust the cross slide first.you may need to do this again a few times as the gibs wear. changing the set screws to better quality screws is not a bad idea either. a cross slide lock is also a great upgrade especially for facing . you just lock the cross slide so it doesn't get pushed back .

If you haven't watched Frank Hoose's videos on youtube ,I highly recommend that you do, he also has a few videos on adjusting the cross slide and compound slide:

There's a great video by Steve Jordan on how to upgrade the compound slide on these lathes, which is to drill two extra hole on the side of the compound slide so you could lock it when you don't need to move it.
Here's the video on the upgrade:

Hope this helped.
Ken.
 
Ckormann said:
Thank you for responding. I didn't mean to imply I was trying to resolve back lash by adjusting the gibs. I should have been clearer about that. What I was trying to say was that in adjusting the gibs and the set screws for backlash, I can get the cross slide to be tight to the dovetail and still move easily, or I can get rid of back lash and have the cross slide still move easly. But I have been unable to have the cross slide tight to the dovetail and get rid of back lash and still move easily. I hope that makes sense.

Also, It is a new lathe.

Chris
Click to expand...
Here's some information that might help.
 
Lead screws with square threads will have backlash, the only way around this is a loaded lead screw nut/nuts. If one loads a non rolling element screw/ nut assembly it will have a good deal of friction, the answer is ball screws which may be loaded and exhibit little friction.

If you are not interpolating arcs where an axis must change direction and lead screw lash becomes a problem just ignore it as has been done for the last 120 years with manual machines.
 
Thank you everyone. A lot of great information.

I am very familiar with Frank Hoose's videos and website. I have watched all of his videos on the 5100 multiple times and it was really helpful.

So what I am taking from all the responses is that I am probably going to have to live with a little backlash, which I can. It's not a big deal. I just wanted to know how experienced machinists dealt with this.

I think Roy and Ken are on the right track about taking time for the mating surfaces to wear in. I watched a video that showed how to help that process along. It involves taking apart the cross slide and compound and removing the lead screw. Then apply some WLG to the cross slide and re-attach it to the dove tail without the lead screw, then aggressively move the cross slide back and forth. As it gets easier to slide, tighten the gibs a little and repeat. It needs to be done for a significant period of time, but I imagine that will vary from person to person. I did perform this process, but probably not for long enough so I am going back to square one and start over.

Thank you everyone.

Chris
 
Ckormann said:
Hi all,

I am new to machining and recently purchased an LMS 5200 lathe. I am having a difficult time adjusting the cross slide and the compound.

I am struggling to get the cross slide to move freely but be tight enough that it does not lift, for example, on a facing cut. I have the same issue with back lash. I have to make it pretty tight to remove the backlash, but then there is too much resistance when trying to move the cross slide.

I also have a back lash type behavior with the compound, but it is not back lash in the true sense. It is caused by the way the compound lead screw is held in place. There is about 20 thousands of play that the lead screw has with the bushing (for lack of the proper word to describe it) that holds the lead screw in place.

If anyone has experience with the LMS 5200 I would greatly appreciate your advice.

Thank you,
Chris
Click to expand...
I had the very same lathe for a year or so. I couldn't take it anymore and bought a full size lathe. It was very expensive for something that really wasn't much use. I try to steer anyone away from jacking with mini type machines as it's just a waste of time and money. Spend your money on something that weighs at least 1200 lbs. It was a costly but valuable learning experience for me.
 
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