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Sheldon 11 inch carriage gib

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wiwoods

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#1
My 11 inch K model Sheldon does not appear to have a carriage Gib and in the similar parts lists it does not show this lathe using one. When cutting and in particular parting there seems to be some upward movement in the carriage which I can see if I lift on the handwheel. Any suggestions on how to minimize this movement?
 

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Lordbeezer

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#2
Have you tightened the carriage lock a little to see if it gets better..bolts in back in picture one tight?
 

dlane

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#3
Cutting forces should push down on the front prismatic way when cutting, not lifting. Gravity holds it down
The three screws on the back of carriage that hold it to the flat way should tighten up a little if needed.
That’s how my SB10L is no carriage gibs
 

Richard King 2

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#4
Hi, Did you lock the saddle lock? I am not sure this is your model but most lathe builders used the same basic design and this manual looks similar to your machine. The picture on left shows the saddle hold down and that is about all you see on 90% of all lathes. Some also have them under the front too, and a lock part 11 on page 16. http://www.vintagemachinery.org/pubs/2133/15051.pdf

The lathe appears to be 60 + year old so I suspect the bed ways, saddle bottom & top ways, cross-slide and compound ways are worn.

If I were you I would start out cleaning the ways top and bottom and use a .0015 feeler gage and start to see where you can slide it in and under parts. You said you lift the hand wheel I am assuming you mean part 16 on page 14 1/2 ?

Did you clean the chips off when you lifted it? Have you adjusted the 2 set screws item 41 page 16 that tighten the rectangle gib on the cross-slide? and compound? I see the compound has a tapered gib page 17 part 20.

If you clean, measure and adjust things up a bit and you still have issues I suspect you need to get your machine rebuilt. One simple way to see how much wear is in the machine is to clean the ways, crank the saddle (carriage) to the far right, then take a rag and flashlight and clean the rack under the bed and look at the rack teeth up near the headstock and then down the rack toward the tail-stock. I suspect the teeth under there bed will be 2 times as wide as they are up under the head stock end.

That's a simple way to verify the machine is worn and needs a rebuild. Check things out and tell us more. I see your in Siren, I have a cabin in Hayward and drive up there several times during the spring and summer. If you can wait I can stop by and take a look. Also there is a super machine rebuilder in Roberts who could rebuild the ways. Rich
 

Richard King 2

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#5
Cutting forces should push down on the front prismatic way when cutting, not lifting. Gravity holds it down
The three screws on the back of carriage that hold it to the flat way should tighten up a little if needed.
That’s how my SB10L is no carriage gibs
The rear hold down lifts up when cutting force is applied on the front of saddle. If the machine had a taper attachment it would be less likely to lift. I have bolted a counter balance steel bar on the back of the saddle several time to help weigh down the saddle back there.
 

wiwoods

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#6
Have you tightened the carriage lock a little to see if it gets better..bolts in back in picture one tight?
Hi, Did you lock the saddle lock? I am not sure this is your model but most lathe builders used the same basic design and this manual looks similar to your machine. The picture on left shows the saddle hold down and that is about all you see on 90% of all lathes. Some also have them under the front too, and a lock part 11 on page 16. http://www.vintagemachinery.org/pubs/2133/15051.pdf

The lathe appears to be 60 + year old so I suspect the bed ways, saddle bottom & top ways, cross-slide and compound ways are worn.

If I were you I would start out cleaning the ways top and bottom and use a .0015 feeler gage and start to see where you can slide it in and under parts. You said you lift the hand wheel I am assuming you mean part 16 on page 14 1/2 ?

Did you clean the chips off when you lifted it? Have you adjusted the 2 set screws item 41 page 16 that tighten the rectangle gib on the cross-slide? and compound? I see the compound has a tapered gib page 17 part 20.

If you clean, measure and adjust things up a bit and you still have issues I suspect you need to get your machine rebuilt. One simple way to see how much wear is in the machine is to clean the ways, crank the saddle (carriage) to the far right, then take a rag and flashlight and clean the rack under the bed and look at the rack teeth up near the headstock and then down the rack toward the tail-stock. I suspect the teeth under there bed will be 2 times as wide as they are up under the head stock end.

That's a simple way to verify the machine is worn and needs a rebuild. Check things out and tell us more. I see your in Siren, I have a cabin in Hayward and drive up there several times during the spring and summer. If you can wait I can stop by and take a look. Also there is a super machine rebuilder in Roberts who could rebuild the ways. Rich
 

wiwoods

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#7
Thanks for the info, my lathe is slightly different as it does not have the Gib 55,56,57 shown on page 16. The cross slide gib (11) is tadjusted, and the hold down (10) on the left is tight. When I tighten the cross slide lock (10 on the right side) it does get better. I will take it all the way to the right and see if it improves.
 

wiwoods

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#8
Have you tightened the carriage lock a little to see if it gets better..bolts in back in picture one tight?
Yes it does improve with the carriage lock.
 

benmychree

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#9
You might check and see if there are shims under the rear gib, if there are, you may be able to remove them and improve the situation, but depending on wear on the ways near the chuck, shims being removed may make it too tight at the right hand end of the carriage's travel. I think Rich's suggestion of weighting the back of the carriage is a good idea.
 
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Lordbeezer

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#10
You should be able to find a happy spot using carriage lock until RK can get by..also make sure the slotted head bolts going thru top of carriage to apron are tight.
 

nuturner

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#11
Please don't take offense. I hate to add this but just gotta offer the thought. Is the cutting tool centered on the axis of the work? A cutting tool that registers too low it can raise the carriage assembly.
 
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