# Restore Or Not To Restore...



## cdhknives (Jun 3, 2015)

Doing some heavy thinking about my lathe.  Here's the laundry list of worn out items:

Leadscrew worn and gouged. tops of AMCE threads worn round
Tumbler gears worn thin, basically to thin triangles with no top flats
Bearings pitted and noisy
Bed with several thou wear at headstock
Large 2 step pulley on countershaft bent/wobbles

All are fixable, but by the time I spend that much $$$ I'm over halfway to a better quality, heavier duty machine like a PM1127.  http://www.machinetoolonline.com/PM-1127-VF.html

I've already put a bunch of money into it for a QCTP, tooling, collets, etc.  I can get much of my $$$ back out of those...all are less than 2 years old.  Many major parts of this lathe are in good enough condition to be saleable.  QCGB is good.  Tailstock is good.  Other gears are good.  Motor is quiet and strong.  Stand is a beast.  No cracks or repairs on any of the cast parts.

Kinda hitting a wall here...someone talk me out of selling out and buying a newer machine!


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## eeler1 (Jun 3, 2015)

Sorry, I'm with the angel on your left shoulder.  Sounds like you really just need a little push to get that PM.  Bed wear really isn't fixable, just something you'll have to tolerate and work around it.  The other items listed tell me that you'll soon be into new bushings, etc, maybe with no end in sight.  Do you enjoy the restoration or being able to do work with it?  

I see the atlas is an heirloom, so sentiment may be involved, maybe get the PM and keep both till you can divest of one without the heavy heart. 

I've never owned a new machine, but have used them.  Gotta say, everything is tight, no wobbly stuff, feels nice like closing the door in a brand new car.


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## brino (Jun 3, 2015)

cdhknives said:


> someone talk me out of selling out and buying a newer machine!



I believe you are talking to the wrong crowd for that......



eeler1 said:


> feels nice like closing the door in a brand new car.



Except you know that the resale value won't drop as fast! 

-brino


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## Franko (Jun 3, 2015)

It depends on what you like to do. Do you want to work on a lathe or work with a lathe?


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## wa5cab (Jun 4, 2015)

First step is to get the actual delivered to your door price of a new machine that is actually as good as the Atlas and that will last another 65 years with no maintenance other than proper lubrication.  Include the cost of any tooling you have for the Atlas that isn't worn out and that won't work with the new machine.  Chucks, steady rest, anything for the tailstock if the new tailstock isn't 2MT, that sort of thing.


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## cdhknives (Jun 4, 2015)

My quick costs for a restoration of the worst of the wear:
Precision bearings, $800+
Bed regrind and scraping, $500
Precision leadscrew stock and machining $250+

Kinda hard to argue that over $1500 in restoration resulting in a nearly good as new but small and light duty 250 lb lathe is hard to justify.  Currently my thinking is to use it within its limits as a learning tool (its current role) and when my skills grow enough to actually be able to use the better precision and bigger lathe upgrade as future needs (wants!) dictate.

At least, that's my thinking.  As much as I like my 10F, it is always going to be a light duty machine capable of only so much precision...and I hope to see some moderate gunsmithing in my future...not really enough machine for that.


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## wa5cab (Jun 4, 2015)

Where did you get the $800 price for Class 3 bearings?


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## cdhknives (Jun 4, 2015)

wa5cab said:


> Where did you get the $800 price for Class 3 bearings?



Amazon.com, only place online I could find them...and that's with standard price for the front cup as the #3 grade is out of stock.  Clausing parts personnel estimated $800 but wouldn't give a precision class without a formal quote/order.  Several other online bearing places said they couldn't get #3 grade...meaning they didn't want to mess with a one off order.  Standard precision Timken brand is still over $250 shipped from 3 places I checked...mostly because of the front cup at almost $150.

http://www.amazon.com/Timken-Tapere...8&qid=1433466834&sr=8-2&keywords=timken+16150
http://www.amazon.com/Timken-Tapere...&qid=1433466899&sr=1-1&keywords=timken+16284b
http://www.amazon.com/Timken-Tapere...&qid=1433467013&sr=1-2&keywords=timken+14125a
http://www.amazon.com/Timken-Tapere...&qid=1433467136&sr=1-2&keywords=timken+14276b


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## cdhknives (Jun 4, 2015)

I talked to a couple of rotating equipment engineers at the refineries where I spend much of my time.  Conclusion is the current high quality (not chi-com) standard bearings are 95%+ likely to be better than original equipment...so I bought a set and have them en-route.

Since I marked and trued my 3MT dead center in the old spindle, I'll have a good reference to see how good the new bearings are...


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## wa5cab (Jun 5, 2015)

As I think I wrote in an earlier thread on this subject, the ANSI/ABMA specs on Class 2 bearings limit how bad bearings can be.  But they don't say that they must be that bad.  Assuming that bearings are tested to class like for example resistors used to be, you could buy a Class 2 bearing and actually get one that could have met Class 00.  If the line had met it's quota for 00's and 3's that day.  I started to suggest earlier that you buy a set of Class 2's.  You'll probably be better off than you are now.

The proper place to measure spindle runout is on the OD of the register.


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## eeler1 (Jun 5, 2015)

I wonder if a person could reverse the leadscrew end for end and reduce leadscrew backlash?  It might take some adjusting or extending or drilling/tapping for modified ends or such.  Not suggesting it would work, but seems like 99% of my use on the leadscrew is in right/left direction.  Maybe less wear on the other side of the thread?  Curious if anybody has tried it and how it worked out.


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## yendor (Jun 5, 2015)

It would not make any difference if you turned it around.
the backlash is created by the width of the Valleys that have been worn between the threads.

Acme Threads Start out with a Flat Top almost like an inverted "U". but Flat on Top.
All wear occurs on the sides of the thread and the FLAT Top of the Acme Thread is reduced as the sides wear and create wider valleys.
Eventually the Valleys are worn to the point the top of the thread becomes pointed like an inverted "V".

By that time the Valleys have become wider and there lies the backlash. To get from one side of a thread to the next you end up turning the lead screw with nothing happening until the other side of the thread finally comes in contact with the Half Nuts.


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## cdhknives (Jun 5, 2015)

My leadscrew has been reversed.  The previous owner/abuser before my grandfather bought it in 1955 apparently used it for grinding, and the headstock end threads were round and gouged.  My GF took the leadscrew off and in to the plant machine shop and had it remachined to swap it end for end.  It works.  It looks strange because the long unthreaded portion normally at the headstock is at the tail end, but it works and it got the 'fresh' threads to the headstock end where they will get used.

So yes, it can be done, and it works, but I'm not convinced it is better than buying a section of ACME blank and machining a new one.


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## yendor (Jun 5, 2015)

If one end has considerably less wear on the threads then yes it makes sense that it would work. Because you now have FULL Threads where you will use them. But for many of us the lead screws are worn along the entire length. When that happens it makes no difference.


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## cdhknives (Jun 5, 2015)

It also doesn't help with backlash from half nut wear, but it MAY help in some cases...IMO backlash wear is annoying, but quite managable.  Bed wear is killing me...


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## wa5cab (Jun 5, 2015)

Another problem with flipping it is that 2-1/2" of the right end is 1/2" dia.  When you flip it, you have to cut that off as the left end of all Atlas 10" and 12" lathe lead screws are either 5/8" or 3/4" dia.  So you will have to relocate the right bearing about 2-1/2" to the left.


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## mattthemuppet2 (Jun 6, 2015)

is the bead wear that much of a killer? in other words, do you turn stuff that's long enough to produce a measurable taper? not criticising or anything, but most of what I've read about bad wear says that it has to be truly shagged out before you start getting measurable taper. if it's 2 thou low at the headstock that'll drop the cutter by that much which = tiny difference on the diameter (which is way beyond my mathematical abilities to work out, just that statement was hard enough). sounds like a NOS lead screw, half nuts and this bearings fixes most of it, the rest you can fix with some scrap and ingenuity


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## Fairbanks (Jun 6, 2015)

I vote for a rebuild.


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## wa5cab (Jun 6, 2015)

For an analysis of the diameter errors caused by 10 thou vertical error between headstock and tailstock or by that amount of wear if you are running the carriage from an unworn bed area into the area with the wear, see Downloads in  Machine Manuals, Catalogs & Drawings\Atlas/Craftsman/AA\A/C Lathes\A/C Charts, Tables & Misc Docs\Tailstock Height & Bed Wear Errors.txt.  Note, however, that this only addresses diameter errors caused by vertical errors.  Differential wear on the back of the bed is another matter.  10 thou wear on the back of the rear way would result in 0.020" diameter error if you started the pass all the way down at the unworn tailstock end.  But of course, that seldom happens (and is the reason why there is usually no wear at the tailstock end).


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## cdhknives (Jun 6, 2015)

Cleaned everything since it was all apart, got both races and the right bearing today so they are installed, just waiting on the left bearing.  Spindle is reassembled and loose in the headstock.


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## cdhknives (Jun 6, 2015)

wa5cab said:


> Another problem with flipping it is that 2-1/2" of the right end is 1/2" dia.  When you flip it, you have to cut that off as the left end of all Atlas 10" and 12" lathe lead screws are either 5/8" or 3/4" dia.  So you will have to relocate the right bearing about 2-1/2" to the left.



On very close inspection there appears to be a sleeve around the leadscrew where it enters the QCGB.  The right side bearing is about as far right as possible...no signs of remounting (empty holes in empty real estate sufficient to account for the extra length mentioned above).  There is, however, plenty of room to the right of the rack gear to do this if desired.


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## cdhknives (Jun 9, 2015)

All bearings installed and test run.  Huge difference in noise level.  I still need to reinstall the back gears and headstock cover before I really set everything up and start making chips again...


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## scrdmgl (Jun 9, 2015)

cdhknives said:


> Doing some heavy thinking about my lathe.  Here's the laundry list of worn out items:
> 
> Leadscrew worn and gouged. tops of AMCE threads worn round
> Tumbler gears worn thin, basically to thin triangles with no top flats
> ...



Personally, I would buy a good used industrial grade 14x40" Tool Room Lathe for that kind of money. Not to big, not too small for general purpose and the quality way beyond those home shop offerings. Equipment dealers generally are a good source of such machines and most of them don't sell junk and you can try them before you buy.
Many shops going out of business post ads for them also.


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## j_zuilkowski (Jun 9, 2015)

"Bed regrind and scraping, $500"

cdhknives - where can you get an Atlas bed reground for $500?  I spoke to Commerce and they were looking at $1200 plus shipping

Does anyone know of someone that can grind my 12 x 24 late model for less?


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## cdhknives (Jun 11, 2015)

Old bearings:





New bearings:


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## cdhknives (Jun 11, 2015)

j_zuilkowski said:


> "Bed regrind and scraping, $500"
> 
> cdhknives - where can you get an Atlas bed reground for $500?  I spoke to Commerce and they were looking at $1200 plus shipping
> 
> Does anyone know of someone that can grind my 12 x 24 late model for less?



I got the $500 number from a long time career machinist/toolmaker friend as an off the cuff guesstimate.  He lives in New Jersey, so price and availability will vary.  I never got to the point of actually getting a quote from a machine restoration place.  Personally I was considering going to one of the big local machine shops.  They rebuild large diesel engines all the time and should have surface grinders capable of handling this task...but in reality I'm far more likely to use this old Atlas like it is until I am good enough to use the accuracy of a better lathe, and then buy a good used 12 or 14 inch toolroom (or gunsmith) lathe.


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## eeler1 (Jun 12, 2015)

Re grinding can also affect alignment of the qc gearbox and lead screw.  If you can live with the wear, and it would have to be pretty bad to have a much effect on short work, then forget the re grind.  

Looks like you are making progress on the rebuild.  You'll be able to offer first hand advice to new atlas owners yourself.


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## bpratl (Jun 12, 2015)

Franko said:


> It depends on what you like to do. Do you want to work on a lathe or work with a lathe?


That's a great point, years ago I made that mistake and I ended up "working on the lathe". Bob


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## wa5cab (Jun 12, 2015)

Actually, this site caters to both ways of thinking.  Most of the time, for example, I would rather be working "on" a lathe, radio or vehicle than "with" it.  That attitude is in the minority but none-the-less not subject to disparagement.


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## stupoty (Jun 12, 2015)

cdhknives said:


> My quick costs for a restoration of the worst of the wear:
> Precision bearings, $800+
> Bed regrind and scraping, $500
> Precision leadscrew stock and machining $250+
> ...



My first lathe was a little  warn and flexy in its small bench lathe way (about 100lbs small lathe) it was definetLy a good learning thing and i did manage to make some usfull things on it.

Stuart


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