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Discussion Starter #1
I have been working on a Southworth lift table that has seen some abuse and needs repair. The center shaft which supports the X-frame of the table has some wear on the one end and I am kicking around the idea of whether or not to cut the shaft in the middle and swap the ends around [re-welding it in the center] to get fresh metal for the ends. The ends ride in bronze sleeves and would have lasted a lifetime with just a little care to the other moving parts of the table

The original shaft is very smooth and has no mill marks at all. What I need to know is just how accurate a piece of cold roll steel is. It would be much easier to replace the entire center shaft than to remodel the old shaft as previously stated.

The tolerance of the original shaft was so tight that I had to scrape and sand off the paint and welding spatter to remove it. Not easy on an 800 pound lift table http://www.southworthproducts.com/content118.html

The table frame shown is made of 3/4" steel plate and is heavy and a bit dangerous to take apart...
 

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The weld points would be stronger than the piece itself, (and you could get by with X750 Steel, btw), and yet.........I'm a fan of (even though I was a competent and Certified Welder for many years) replacing what's compromised. Less work, less headache.........

But that's just "me" showing my signs of age.......lol.

Would have to see pictures of the "abuse" to really say. Grab your video camera and take a brief video of what you are looking at. It'll be easier to speak to your needs, with something to look at together, since I'm not in your neighborhood.

"Christmas" is coming........you could always lobby now, for a new one?!


-Soupy
 

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Shafts are one of those things that you are not supposed to cut.
Up to you.
When you are talking about a hinge shaft, you are usually talking about some kind of "pin". think about this, if the barrels are bad on pin barrel hinges, do you cut the pins off so you can turn them over and reuse them??

OK in this case you can put a sleeve over the cut shaft to line it up right.

Hey try it, if it works great deal

IF IT fails, go get a new shaft and install it, only out the time effort and .
 

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Discussion Starter #5
My main question is now how much variation could be expected in diameter for a cold roll round. The one I have now seems to be about ten thousandths--- From 1.148 to about 1.158. The lift has 'lubricated for life' inserts that have tight tolerances. The reason the tolerances must be close is that the new pin must pass all the way through the inserts on both sides of the table. The contact surfaces after assembly are only the last two inches of the ends of the pin.

So really,the blemishes on the center of the shaft where it is welded are not important so long as they remain a bit under-size of 1.500 inches. If I can buy a shaft I will get one. I was going to post pics [later] of the entire build, if that is OK?
 

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±.010 is a typical industrial standard for Cold Rolled Steel. If you need it tighter than that, you can always "turn it down" on a Lathe. the "Total Run Out Tolerance" is applicable too.

Ususally "Total Run Out within .005 of Datum A" for Industry.

-Soupy
 

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Discussion Starter #7
±.010 is a typical industrial standard for Cold Rolled Steel. If you need it tighter than that, you can always "turn it down" on a Lathe. the "Total Run Out Tolerance" is applicable too.

Ususally "Total Run Out within .005 of Datum A" for Industry.

-Soupy
Thanks. I just talked to my brother and he knows where to get cut-offs for cheap. It looks like cold roll is the way to go. When the project is complete,I will do a write-up with pics..

As for Wintersols comment,Southport will provide you with expertise on repair and can get any part you want ,but they have a $50.00 minimum order. New permanently oiled bushings should be ordered as well as new wheels for the upper and lower carriage.I also hope that they can furnish me with a weld on hub of steel with the bushing included. The wheels had worn half of 2 axles away and 100% of the other two. The 1.5" shaft had heavy wear on the outside and it ovaled the center hub on just the outside. [can be repaired] Once the bronze bushings are gone,wear quickly occur

It sounds worse than it is. These tables are so overbuilt for my use that I could repair it without any Southport parts at all--just parts I found at Tractor supply. I would rather do it right with Southport parts.because then it is a 3000.00 table for a fraction of that cost.

That is my plan now,but plans might change as the build progresses.
 

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Discussion Starter #8 (Edited)
±.010 is a typical industrial standard for Cold Rolled Steel. If you need it tighter than that, you can always "turn it down" on a Lathe. the "Total Run Out Tolerance" is applicable too.

Ususally "Total Run Out within .005 of Datum A" for Industry.

-Soupy
Wow,there really is plenty of expertise on this forum. I have since found out that the chaft that southworth uses is cold roll Ground and Polished. This grade tends to run maybe .005 oversize plus or minus. Even with the paint removed it drags pretty hard through the oil filled bushings.. I could put a bit of grease in at assembly using the new cold roll, or cut and weld a bit on the old stuff and get new fresh ends with a tighter fit at the bearing surfaces.

I am painting it now. Rusteoleum Hunter Green is nearly a dead match for the OEM color. My brother had the shop precision bore a 4 inch square 3/4" thick to serve as a new hub bearing support collar. The support collar is really the only way that I know to get the hole located perfectly where it should be. The strength will not be compromised at all

I do not know whether or not to add the pictures of the build/assembly to this thread or to start a new one, something like "Rebuilding a one ton Motorcycle lift"
 

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Cold Rolled round shaft that I have seen for the last 30 years is all +.000 and -.004 from nominal. Hot rolled on the other hand has a much bigger tolerance. If you buy CR shaft from any repair shop, I highly doubt it will be out of the tolerance I listed above.

Joel
 
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