# Sb Gibs Coming Loose. Why?



## Pinresto (Aug 9, 2015)

hi, 
 I have a 9" SB lathe. I've been making some little items trying to teach myself the in's and out's of lathe work. When I originally set up my lathe I had the compound and cross feed gibs adjusted to what I thought was perfection. Everything moved smoothly and without any play. Now that I've been using the lathe I've noticed the gib screws are coming loose as I work. 3 times now while working I noticed some play and had to tighten the gib screws. The first time I figured i would have to make some adjustments as I first starting using the machine but now it's just keeps happening. Is this a common problem? Is there a good solution? Does this mean I'm doing something wrong? 
Thanks in advance


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## T Bredehoft (Aug 9, 2015)

Gib screws often have nuts on them to maintain their position, are yours without nuts? Were there nuts originally (are there wear spots where the nuts used to be?


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## woodtickgreg (Aug 9, 2015)

A pic would help. My 10L has a set screw that locks the adjustment screw. A 9 is probably different.


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## Pinresto (Aug 9, 2015)

I'll get some pics shortly. I'm not home now. My gib screws have no nuts and no way to lock them. The screws sit near fush with the holes they go in. No room for a nut. Based on pics I've seen online they are as they should be. Pics to come.


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## RJSakowski (Aug 9, 2015)

Many lathes use a brass pin between the adjustment screw and the gib to prevent chewing up the gib.  Is it possible that your lathe is missing those?  If your adjustment screws are long enough, you can make some pins to expose enough of the thread to put a lock nut on.  An 1/8" or 3/16" pin should be enough to allow adding a lock nut.


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## Redirish (Aug 9, 2015)

Pinresto said:


> hi,
> I have a 9" SB lathe. I've been making some little items trying to teach myself the in's and out's of lathe work. When I originally set up my lathe I had the compound and cross feed gibs adjusted to what I thought was perfection. Everything moved smoothly and without any play. Now that I've been using the lathe I've noticed the gib screws are coming loose as I work. 3 times now while working I noticed some play and had to tighten the gib screws. The first time I figured i would have to make some adjustments as I first starting using the machine but now it's just keeps happening. Is this a common problem? Is there a good solution? Does this mean I'm doing something wrong?
> Thanks in advance


 No, the 9 inch SB doesn't use locknuts. Had the same problem with mine. You can remove the gib screws, clean the screws and the threaded holes with alcohol, coat the screws with silicone gasket sealant, install and adjust them and let the sealant cure 24 hours. This will keep them in place pretty well, and they can still be adjusted when needed.


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## brav65 (Aug 9, 2015)

Green lock tite would be an option.  It breaks loose with much less pressure than red or blue.  I use it on the pivot screw on my pocket knives.


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## Ulma Doctor (Aug 10, 2015)

this may or may not help out,
in a couple situations not lathe related, i have used a brass set screw in place of the allen head set screw.
i would modify the brass set screw in 2 ways, i would turn the first 2 threads off the screw on the non driven end to make a crush pad.
secondly i would purposely lightly/moderately deform the threads longitudinally with a small but wide cold chisel , 180* opposition on both sides of the screw.

the crush pad expands slightly upon use, the reason for removing the first couple threads, (you'll thank me upon removal)
the deformed threads will cling to the internal v thread and take up excess clearance. they will move -but only when you want them to move with tools.

we are talking about gib screws so a brass replacement would have sufficient strength,
although you should be more gentle on brass than you would a steel screw


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## JR49 (Aug 10, 2015)

"Vibra-Tite"  has been on my shopping list for some time now, but I keep forgetting to get some.  I've been told that this stuff works great and is made for your situation exactly.  It stays slightly pliable, so that adjustments can be made, without breaking the bond (like locktite) but holds the screw from turning on its own.  JR49


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## DoogieB (Aug 10, 2015)

Thanks for the heads-up on the Vibra-tite!  I didn't realize something like that existed as a few times it would have been very handy.


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## Pinresto (Aug 11, 2015)

JR49 said:


> "Vibra-Tite"  has been on my shopping list for some time now, but I keep forgetting to get some.  I've been told that this stuff works great and is made for your situation exactly.  It stays slightly pliable, so that adjustments can be made, without breaking the bond (like locktite) but holds the screw from turning on its own.  JR49



This sounds like my answer. I'll order some today. Thanks, I had not heard of this product before.


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## brino (Aug 11, 2015)

Pinresto said:


> Now that I've been using the lathe I've noticed the gib screws are coming loose as I work. 3 times now while working I noticed some play and had to tighten the gib screws. The first time I figured i would have to make some adjustments as I first starting using the machine but now it's just keeps happening. Is this a common problem? Is there a good solution?



Hi Tony (and everyone!)

While I am glad to learn about the Vibra-Tite product and the silicone sealant idea, I do have locking set-screws on my SouthBend 9 inch for both the cross-slide and top-slide.
I thought so when I originally read this thread, but it took me this long to get around to verifying it.
Greg is right!

In the picture below the items are: 
1) the top-slide tapered gib (the notch is where the cheese-head fits)
2) the hole for the top-slide locking set screw
3) the cheese-head gib tightening screw (standard slot drive; it goes in the dark recess above the gib!)
4) the top-slide locking set screw
5) the cross-slide gib adjustment locking set screw

Upon dis-assembly it appears that the locking set screws bear right on the threads of the cheese-head adjustment screws.
I considered changing the set screw to one with a brass tip and allen head, but maybe the slot acts like a safety device.....try to tighten it too much and the driver cams out of the head saving the adjustment screw threads. With an allen head you might be able to tighen it too much and damage the adjustment screw threads.

-brino
(and yes I know my lathe is filthy )


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## woodtickgreg (Aug 11, 2015)

I think there is supposed to be a little brass shoe that goes under the locking screw. I had to make new ones for my lathe and just cut short pieces of brass rod for that purpose. This way when you tighten the lock screw it pushes the brass shoe against the adjustment screw and locks it in place without damaging the threads. So your set up is the same as my 10L. That's not a dirty lathe ......it's just well oiled.


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## brino (Aug 11, 2015)

woodtickgreg said:


> I think there is supposed to be a little brass shoe that goes under the locking screw.



Thanks Greg! 
That makes perfect sense, I did not poke around in the set-screw hole looking for the brass pad.
I should verify that they are still there.

-brino


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## lugnard (Aug 14, 2015)

I have seen an idea somewhere where the screw was grooved I think with a small cutoff wheel and a piece of mono filliment laid in. I would try it with a non original screw first and see how it works tho. I know I saved a pic of it but of course can't find it...yet.

Harry


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## lugnard (Aug 14, 2015)




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## lugnard (Aug 14, 2015)

I like this idea better!!

Harry


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