Worn lathe ways and more - where to start in rebuilding grandpa's lathe?

Blackbeard95 · Dec 25, 2018

I have a Boxford VSL that was given to me by my late grandfather - a former prisoner of war, he started a chemical company when he got home after the War. My lathe originally belonged to his company and it got a lot of use over the years so the ways are badly worn (.005").

I am right now moving my machines to Detroit, ironically I'm working for a company that is well known for making lathes, but I'm not in the turning division so I'm far from an expert on this topic. I'd really like to get this lathe restored to perfect condition - or about as perfect as I can get, and I'm going to need the advice of some of you older more experienced guys to get it done right and not screw up.

Right not I'm taking the lathe apart so I can move it to my new house in Michigan. While the deconstruction is necessitated by weight reduction, it's also a good opportunity for me to bag-and-tag all the parts I will catch up with later. The question that I keep wondering about, is what am I going to do with these ways? I have heard that it's bad practice to scrape in visible surfaces on a machine tool, which leaves me looking at grinding. How does the grinding process work? I take the ways off the lathe, bring it to a machine tool grinder, then they grind it all pretty and precise? How much should I expect to pay for this? The lathe is 20" between centers probably 3 feet total length on the ways.

Now to make things more difficult - I pulled out all 4 bolts that hold the lathe ways onto the cabinet. Despite doing this, I can't lift the ways off. I think there might be some kind of leveling epoxy or something holding the ways in place. I tried putting a car jack under the ways, but I don't have the confidence to crank that thing tight. Should I go ahead and force the ways off the cabinet or am I rightly worried that I will break something?

What other things should I check or replace? So far: I will check the spindle bearings, pre-load, and replace if need be. Cross slide needs work, so do the half nuts. Compound is in great shape. And the lathe will get a fresh coat of gray paint.

Please advise...

fciron · Dec 27, 2018

Might try the scraping and machine rebuilding sub forum further down in the Open Discussion section.

As far as I know scraping is the approved method for trueing machine surfaces, visible or otherwise. You might wish to have the waiys ground to save the necessity of scraping thirty inches .005" deep. Once the ways are straight the head stock, tail stock, and carriage need to be scraped into the new ways, then the cross-slide.

When you say the ways are out .005" that does not necessarily translate to .005" error in the work. It's also possible that much of the slop in the cross slide can be taken up by adjusting the gib.

I understand the desire to honor your grandfather by restoring his lathe, but it may not be necessary for the work you want to do. You might consider honoring him by making some stuff with his lathe. Then, if you can't hold necessary tolerances, decide if you want to rebuild the whole machine.

If you decide to go that route you'll find plenty of help in the rebuilding forum. I'm sure they'll be able to refer you to good resources in the Detroit area.

fciron · Dec 27, 2018

Oh, found a manual for you.
http://www.pulse-jets.com/boxford/boxford_know_your_lathe.pdf

There doesn't seem to be an additional hold down. I'd suggest prying upwards on the bed with wood. This will give you a direct feel of how hard you're pushing and the wood will not dent or scrape the lathe.

You might also try a solvent like mineral spirits around the bed feet to soften years of accumulated crud that may be acting like glue.

Cole2534 · Dec 27, 2018

Grandpa would probably be happier to see you using his worn but functional lathe, rather than have it in a pile of pieces with a half completed 'rebuild'.

iwananew10K · Dec 27, 2018

.005" is not much, should still have lots of life.

is your belting still connected? that will keep it tight down to cabinet.

Hodge · Dec 27, 2018

Before jacking or prying on the lathe post up some clear pics of the lathe from several angles. That will help others get a clear idea of what your dealing with.

HuFlungDung · Dec 27, 2018

iwananew10K said:
.005" is not much, should still have lots of life.

That is something I wonder about: as the lathe is getting used and worn, at what point does the user notice that it is worn? Seems like the new owner always thinks it is important to fix it immediately, but one has to wonder how the machine got that worn to begin with, if it was intolerable to make parts with.

There are quite a few other factors that determine how straight the machine turns, and in real life, ordinary lathes are not often used to turn long skinny cylinders where flexure is not a bigger problem than how unworn the bed is. For the most part, many lathe parts have a journal here and there where diameter and straightness is important, and the lathe is good enough to turn each of those lengths without fiddling around during the cut.

Grinding the bed and then machining the carriage to straighten it up a tad, drops the height of the apron a little and requires a bit of fiddling to get the leadscrew and feed rod aligned.

Cole2534 · Dec 27, 2018

HuFlungDung said:
There are quite a few other factors that determine how straight the machine turns, and in real life, ordinary lathes are not often used to turn long skinny cylinders where flexure is not a bigger problem than how unworn the bed is. For the most part, many lathe parts have a journal here and there where diameter and straightness is important, and the lathe is good enough to turn each of those lengths without fiddling around during the cut.

I think it's the newer folks that have trouble with that, I know I sure did. (It didn't help that I was trained on genuinely mint equipment. We had a 12x30 Hendey, bought new, that I bet didn't run 4hrs a month in the 4yrs I worked there. My first 9A was not so fortunate.) Somewhere along the way one gets the idea that if it won't hold .0005" across the C-C length in 1/2" diameter 1018 then it's junk. But, reality is a far cry from that.

Once one cuts various parts, they learn where the ways dip (hint- it's the first 2" in front of the chuck) and then work their setups to mitigate that.

It's a bit of a Dunning-Krueger effect, where one doesn't know what they don't know and thus they take inappropriate courses of action to repair.

michiganbuck · Dec 27, 2018

QT.... I tried putting a car jack under the ways, *Don't break it.
Don't use any spray can cleaner on any machine but use a oil and mineral spirits rag wipe.
.005 is not such a big deal...

*Wait for PM guys knowing that machine to give advice.

Detroit edge tool could put that whole machine on a chuck and grind bed near dead flat
Machine Ways & Rails, Shear Blades & Shear Knives by Detroit Edge Tool Company

26 or 28" I could grind but don't want the job..
One needs to trig out the take away because you dont take the same from a V as you take from a flat..

* Very easy to tip such a machine over and break it..many bolt 4x4s to legs to make it be double wide.

jim rozen · Dec 27, 2018

Blackbeard95 said:
Please advise...

From the photos you posted, the machine does not look that bad. Clean it up before re-assembly and run it.

9100 · Dec 27, 2018

Cole2534 said:
It's a bit of a Dunning-Krueger effect, where one doesn't know what they don't know and thus they take inappropriate courses of action to repair.

Thank you for the reference. I was aware of the effect but not the name, which allowed me to Google it. I am not trying to do a threadjack so I will only say that I briefly had an employee who embodied the principle.

Bill

projectnut · Dec 27, 2018

Blackbeard95 said:
I have a Boxford VSL that was given to me by my late grandfather - a former prisoner of war, he started a chemical company when he got home after the War. My lathe originally belonged to his company and it got a lot of use over the years so the ways are badly worn (.005").

I am right now moving my machines to Detroit, ironically I'm working for a company that is well known for making lathes, but I'm not in the turning division so I'm far from an expert on this topic. I'd really like to get this lathe restored to perfect condition - or about as perfect as I can get, and I'm going to need the advice of some of you older more experienced guys to get it done right and not screw up.

Right not I'm taking the lathe apart so I can move it to my new house in Michigan. While the deconstruction is necessitated by weight reduction, it's also a good opportunity for me to bag-and-tag all the parts I will catch up with later. The question that I keep wondering about, is what am I going to do with these ways? I have heard that it's bad practice to scrape in visible surfaces on a machine tool, which leaves me looking at grinding. How does the grinding process work? I take the ways off the lathe, bring it to a machine tool grinder, then they grind it all pretty and precise? How much should I expect to pay for this? The lathe is 20" between centers probably 3 feet total length on the ways.

Now to make things more difficult - I pulled out all 4 bolts that hold the lathe ways onto the cabinet. Despite doing this, I can't lift the ways off. I think there might be some kind of leveling epoxy or something holding the ways in place. I tried putting a car jack under the ways, but I don't have the confidence to crank that thing tight. Should I go ahead and force the ways off the cabinet or am I rightly worried that I will break something?

What other things should I check or replace? So far: I will check the spindle bearings, pre-load, and replace if need be. Cross slide needs work, so do the half nuts. Compound is in great shape. And the lathe will get a fresh coat of gray paint.

Please advise...

As suggested by others, if the wear is only .005 the machine is still capable of making quality parts. I have a 1916 Seneca Falls Star #20 lathe with double the wear and I still have no trouble making accurate parts.

If you feel grinding is an absolute necessity there are several shops in the Chicago area that are more than capable. A few years ago I purchased a used Sheldon lathe from a member here. He had rebuilt the machine including having sent out the bed to have the ways ground.

If I recall correctly the bed was sent to American Grinding in Chicago. I am currently out of town, but I can verify that next week when I get home if you're interested.

Grinding - Chicago, Illinois - American Grinding & Machine Company

The price back in 2001 was about $400.00. I'm sure it would cost considerably more today.

michiganbuck · Dec 27, 2018

It is not uncommon for a person to mis measure the bed error...because often one will indicate the side or top of a round part and so clocking on a radius with a ball indicator point. long travel down a smaller part can give a lot of checking error.

Cross across the top of a part with indicator is often a better test.but that can be error if the tail is not at the same height as the head.

Tool bit riding .0025 above and below center does not make much error on a part.
Bed wear going more down for the length of the part may make no error at all.

fciron · Dec 27, 2018

iwananew10K said:
.005" is not much, should still have lots of life.

is your belting still connected? that will keep it tight down to cabinet.

Ooh, I peeked in the manual and that is a possibility . I'm surprised I haven't done that yet.

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Worn lathe ways and more - where to start in rebuilding grandpa's lathe?

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