# Planing lathe bed



## PeterT (May 14, 2020)

Look at the first sequence of interrupted cuts. How does a lathe get that way? (Or maybe come 'delivered' that way?)
No amount of test bars or jacking legs up to fiddle lathe twist is going to fix a machine with this geometry.
Sure turned out purdy in the end. Wouldn't it be great to have a shop down the street that did this kind of work?


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## Johnwa (May 14, 2020)

Most of the wear on the front way was just in front of the headstock. This is where the carriage spends most of its time. I didn’t pay much attention to the rest of it.
I have heard that the owner of modern tools has a planer and does lathe beds. I also heard it cost a fortune to get it done. Seeing how quickly that lathe was done though suggests it shouldn’t be too bad.


Sent from my iPad using Tapatalk


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## YYCHM (May 14, 2020)

Is that thing actually planing it like in planing wood or surface grinding it?


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## RobinHood (May 14, 2020)

YYCHobbyMachinist said:


> Is that thing actually planing it like in planing wood or surface grinding it?



it is planing it. Works only with non-hardened beds.


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## Alexander (May 14, 2020)

That type of wear is pretty common. I have worked at production shops that would plan on buying new manual lathes every 5 or 10 years. If the shop has 2 shifts 5 days a week. The lathe might leave the shop with well over 10 thousand hours of run time.


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## Tom Kitta (May 15, 2020)

Some US lathes came with replaceable ways for a reason. Also there is a reason why a good machinist will have no issues working with beaten lathe - most are beaten. The main difference here is time needed to complete work - since time == money it makes sense to replace a lathe at some point.

 I am a bit surprised they did not do the piece in the gap - that thing is way off - maybe they lost it?


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## David_R8 (May 15, 2020)

Would the cross slide need some attention to conform to the new ways?


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## Tom Kitta (May 15, 2020)

Yes, lots of work needed to do - your cross slide drops which means the gears may not mesh well in apron. The head stock needs to be obviously placed back on and re-aligned. At least in this case no need to worry about tailstock being too low. 

This was more economical thing to do few decades ago were we live - now maybe still makes sense in China. India maybe, through they luck expertise.


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## PeterT (May 15, 2020)

In one of the other YouTube links I provided, shows a similar process for re-grinding. They guy had an affinity for Myford lathes & rebuilt them into spectacular condition c/w scraping all the necessary surfaces. I'm not actually sure if Myford ways were hardened or not but that's what he had done. I wouldn't have thought planing could be as accurate as grinding, or maybe that is a precursor to scraping? I guess it depends on the machine itself & maybe such exist.

David, was wondering the same. The ways are now vertically reduced, there has to be compensation somewhere relative to the original vertical spindle line. Whether they take it off the bottom of the headstock assembly or go after the  carriage / top assembly I cant say. Probably the lathe configuration itself would factor in.


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## trlvn (May 15, 2020)

David_R8 said:


> Would the cross slide need some attention to conform to the new ways?


Yes.  Keith Rucker (Vintage Machinery on Youtube) did a video related to this while rebuilding his Monarch (I think).  The machining on the ways changes the interface between the lead and feed screws and the related gears in the saddle.

Craig


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## Tom Kitta (May 15, 2020)

Of interest is, if the lathe bed has lots of wear, what caused it - we all know its the cross slide moving back and forth on it, right? So what about the wear on cross slide - its not made of some special material and has less surface area then the bed... so wear here should be more. 
So total drop can be quite large.


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## RobinHood (May 15, 2020)

Excellent observations gents.

The video’s comments address most of your questions - especially when Rees Acheson replies to them.

He goes into detail about tool geometry, accuracy, next steps, etc.


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