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Lathe or aircraft carrier anchor?

notwrkg

Plastic
Joined
Jan 31, 2023
Location
Independence, MN
I am now the proud owner of approximately 6,000 pounds of something. It's a early model LeBlond 21 Heavy Duty. The serial number is NF3294. My guess is somewhere in the early 19 teens. If someone can be more accurate and give me an exact year I would appreciate it.

It was not under power but I was told by the seller it was running fine up until they replaced it with a larger machine. I have attached a dial indicator to the carriage and checked ways for wear and it is remarkable flat, showing almost now wear. I then put a 24" straight edge on it and could not find any gap large enough for a .0015 feeler gauge to fit through. The cross slide also shows no wear. The half nut cannot be engaged and the bracket that the threading rod attaches to is broke but I think I can address these without great difficulty. All the internal gears look good. Levers all move , everything seems to turn. The tailstock is tight. I also have a 15" 4 jaw chuck and a steadyrest. As for issues, first there is the drive chain. Has anyone seen a similar configuration? Should it be swapped out for a multi V Belt? second, I was told the machine works fine but there is some play when you come to face off material. I assume that means there is some play in the spindle shaft and how it is held in place. Lastly, the carriage drive and threading rod are powered by a V belt setup that runs off the spindle. It was not the original system. I'm retired and winters in Minnesota are long and the shop is heated to I think it would be a fun project to restore the machine and potentially, it could be an accurate and reliable lathe.

My questions, is it worth it? I could probably sell the steadyrest, chucks, motor and scrap the rest and move on or strip the finish, repaint it and repair thread cutting capabilities and have a pretty decent lathe. I know there are few similar machines out there. Are there other inherent concerns I should be aware of? The play when facing off is also a concern. If it is a bearing issue can it be addressed?

Any help, suggestions, guidance would be appreciated.
 

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You're retired and if your financial ducks are in order, you're at time when you can do the things that bring you the most satisfaction so that decision is yours. Does that satisfaction originate from making a profit from a resale, restoring a machine that represents a piece of our industrial past, producing fine work manually from a century-old machine without relying on electronic aids?? Your call. They all have a place.

BTW--look like a beautiful machine.

Tom B.
 
That is one sheer brute of a lathe. It is a true survivor. Given the lathe's age and the long levers on the headstock, it is a wonder those levers were not broken off and brazed along the way. The drive to the headstock is known as a "silent chain drive" and was quite commonly used by machine tool builders in the 'teens, twenties, and thirties in the USA. It is a good drive system assuming there is not too much wear. Replacing it with multiple vee belts seems like a somewhat major undertaking. The hub of the driven sprocket (on the headstock input shaft) look like it may have a multiple-plate clutch in it. Transmitting the torque for a lathe that size thru vee belts is going to take a number of belts. That brings up how much shaft extension there is on the input shaft to the headstock, how much room for a wider pulley, and modifications to the chain case. My own suggestion is leave well enough alone. If the silent chain and sprockets are OK, soak the chain in some diesel fuel, clean the chain and sprockets well, and run it.

LeBlond used a sliding gear to drive the lead screw from the feed shaft (or feed rod as it is often called). In normal operation, the keyed feed rod would be turning anytime the gear train from the spindle was engaged. When threading needed to be done, the sliding gear was moved to engage the lead screw. The modifications done by a previous owner to the feed rod drive, assuming I understand your post, replaced the original gearing from the spindle (known as the 'quadrant gearing') to the quick change box with a vee belt drive. Obviously there was a need for some different and maybe rapid feed rate that the as-supplied gearing/quick change box did not provide. If the lathe is to be used to its fullest potential, i.e., thread cutting as well as power feeds via the quick change gearbox, then the original gearing (or gearing with the same ratios as per original) between spindle and quick change box has to be reinstalled. It is a question of what the seller of the lathe left either on the lathe or loose with it. I can't imagine why anyone would want to provide a vee belt drive to the feed rod on this size/type of lathe. Some lathe builders and some lathe owners would utilize an independent electric motor drive to provide very fine feeds for lathes with spindles operating at high speeds. On a heavy hog of a lathe like this, the need for very fine feeds does not seem likely. Transmitting torque for very coarse feeds for heavy hogging cuts does not sound like something a vee belt drive would do any better than the original gearing. I'd suggest trying to put the original quadrant and gearing back in place between the spindle and the quick change gearbox. On the quick change gearbox, there may be a metal 'chart' or data plate giving tumbler (the sliding lever on the 'drum' on the quick change box) as well as the shifter lever positions with the rates of feed and threads per inch. On this plate there may also be a listing of change gearing on the quadrant to provide these threads and feeds. This information is needed to re-establish the lathe's capabilities for thread cutting and feed rates.

Overall, the lathes looks like it had a reasonable life in a working machine shop. No signs of abuse or real neglect, and from the pictures does not look like too much is missing or changed beyond what you've posted. The bigger question is: do you have use for this heavy/large of a lathe ? It is a plain bearing headstock and was never really designed as a 'sealed' headstock. Slow speed operation was the rule of the day for this oldtimer. It is a lathe for machining heavy work, hogging lots of metal off rough forgings and castings. It was designed for use with forged carbon steel or high speed steel tools. It has a threaded spindle nose, so if other chucks are wanted for this lathe, backplates have to be machined from scratch. In short, this lathe has a limited pool of likely users. People restoring steam locomotives or steam traction engines or other heavy old machinery would be the likely users of this old lathe. I could see cutting 18" truck brake drums on this lathe with no problem, or boring truck axle hub bearing seats (for repair using shrunk-in sleeves) as possible more common work for this lathe. No modern working machine shop is likely to want it. You are now the keeper of something of a white elephant. Hopefully, you have work for this old girl.
 
I think I remember seeing that machine on marketplace! Glad to see it didn't get scrapped. I would have loved to pick it up as a second lathe if I had room. I'm guessing the play when it comes to facing off is when cleaning up the end of stock the carriage wants to move back from the pressure and play in the rack and pinion. Could check with an indicator against the carriage and verify during a facing op to see if it moves. My lathe does that if I take a heavy cut, I just need to remember to lock the carriage if/when I do a heavy facing op.

I'd keep it and run with it. I've been able to do some really small work (0.187 tool steel) on a 16" swing lathe that maxed out at 500 some odd rpm. I've maxed out the swing several times on it, so I appreciate a large swing lathe.
 
I have one about the same with 16"x120" length. It gets used once every other year or so. Put it in the barn under a tarp. For that huge job, its a godsend to have it.
 
I'd keep it and run with it. I've been able to do some really small work (0.187 tool steel) on a 16" swing lathe that maxed out at 500 some odd rpm. I've maxed out the swing several times on it, so I appreciate a large swing lathe.

Amen to that. One of my college instructors require his students to single-point a Unified screwthread, and turn suitable "thread wires" to measure the pitch of that screwthread on the same lathe. He chose the diameter-and-pitch to be cut -- often finer than the standard UNF.

"The usual" source of thread wire stock was copper-coated steel welding rod. Every student in my class succeeded, and most struggled more with the thread-wire business than with the single-pointing.
 
No NF in serial book but there are NE and NG as of 1920. Here is another likely smaller
 

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That is one sheer brute of a lathe. It is a true survivor. Given the lathe's age and the long levers on the headstock, it is a wonder those levers were not broken off and brazed along the way. The drive to the headstock is known as a "silent chain drive" and was quite commonly used by machine tool builders in the 'teens, twenties, and thirties in the USA. It is a good drive system assuming there is not too much wear. Replacing it with multiple vee belts seems like a somewhat major undertaking. The hub of the driven sprocket (on the headstock input shaft) look like it may have a multiple-plate clutch in it. Transmitting the torque for a lathe that size thru vee belts is going to take a number of belts. That brings up how much shaft extension there is on the input shaft to the headstock, how much room for a wider pulley, and modifications to the chain case. My own suggestion is leave well enough alone. If the silent chain and sprockets are OK, soak the chain in some diesel fuel, clean the chain and sprockets well, and run it.

LeBlond used a sliding gear to drive the lead screw from the feed shaft (or feed rod as it is often called). In normal operation, the keyed feed rod would be turning anytime the gear train from the spindle was engaged. When threading needed to be done, the sliding gear was moved to engage the lead screw. The modifications done by a previous owner to the feed rod drive, assuming I understand your post, replaced the original gearing from the spindle (known as the 'quadrant gearing') to the quick change box with a vee belt drive. Obviously there was a need for some different and maybe rapid feed rate that the as-supplied gearing/quick change box did not provide. If the lathe is to be used to its fullest potential, i.e., thread cutting as well as power feeds via the quick change gearbox, then the original gearing (or gearing with the same ratios as per original) between spindle and quick change box has to be reinstalled. It is a question of what the seller of the lathe left either on the lathe or loose with it. I can't imagine why anyone would want to provide a vee belt drive to the feed rod on this size/type of lathe. Some lathe builders and some lathe owners would utilize an independent electric motor drive to provide very fine feeds for lathes with spindles operating at high speeds. On a heavy hog of a lathe like this, the need for very fine feeds does not seem likely. Transmitting torque for very coarse feeds for heavy hogging cuts does not sound like something a vee belt drive would do any better than the original gearing. I'd suggest trying to put the original quadrant and gearing back in place between the spindle and the quick change gearbox. On the quick change gearbox, there may be a metal 'chart' or data plate giving tumbler (the sliding lever on the 'drum' on the quick change box) as well as the shifter lever positions with the rates of feed and threads per inch. On this plate there may also be a listing of change gearing on the quadrant to provide these threads and feeds. This information is needed to re-establish the lathe's capabilities for thread cutting and feed rates.

Overall, the lathes looks like it had a reasonable life in a working machine shop. No signs of abuse or real neglect, and from the pictures does not look like too much is missing or changed beyond what you've posted. The bigger question is: do you have use for this heavy/large of a lathe ? It is a plain bearing headstock and was never really designed as a 'sealed' headstock. Slow speed operation was the rule of the day for this oldtimer. It is a lathe for machining heavy work, hogging lots of metal off rough forgings and castings. It was designed for use with forged carbon steel or high speed steel tools. It has a threaded spindle nose, so if other chucks are wanted for this lathe, backplates have to be machined from scratch. In short, this lathe has a limited pool of likely users. People restoring steam locomotives or steam traction engines or other heavy old machinery would be the likely users of this old lathe. I could see cutting 18" truck brake drums on this lathe with no problem, or boring truck axle hub bearing seats (for repair using shrunk-in sleeves) as possible more common work for this lathe. No modern working machine shop is likely to want it. You are now the keeper of something of a white elephant. Hopefully, you have work for this old girl.
Thanks for all the information. Unfortunately, the original gears which you referred to as the quadrant gearing is missing, as is the chart that explains the threads based on the quickchange box. It will be a good test of my math skills to see if I can trace the spindle turn rate all the way through to the threads per inch based on the current setup, or I can reassemble it and go from there. Either way, there is work to be done.

I'm surprised the chain drive system is probably original but since it seems sound I will clean, oil and re-install.

Since most of the vital components seems to be present and in good shape I will probably keep moving forward with it with the hopes of restoring it to tight tolerances and fully functional, including threading. As the keeper of the elephant I have to admit, I have no work in mind anywhere in line with what this machine was made for. I bought it more out of interest in saving something destined for the scrap pile. If I can get it operational I will then assess what, if any applications I can come up with.
 
I think I remember seeing that machine on marketplace! Glad to see it didn't get scrapped. I would have loved to pick it up as a second lathe if I had room. I'm guessing the play when it comes to facing off is when cleaning up the end of stock the carriage wants to move back from the pressure and play in the rack and pinion. Could check with an indicator against the carriage and verify during a facing op to see if it moves. My lathe does that if I take a heavy cut, I just need to remember to lock the carriage if/when I do a heavy facing op.

I'd keep it and run with it. I've been able to do some really small work (0.187 tool steel) on a 16" swing lathe that maxed out at 500 some odd rpm. I've maxed out the swing several times on it, so I appreciate a large swing lathe.
Probably the same one. I found it on Marketplace and it wasn't too far of a haul. My approach to the play when facing off will be just as you describe unless I can find something specific. first thing is to make a few repairs and get it back together. Its completely stripped down right now.
 
Have this this that can be emailed if you want to post that address

Fairly certain member Mister Honey sent this to me not quite 20 years ago

From 1911, its about 7Mb
 

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Spindle play will have to be evaluated. Generally the bearing caps can come off, often there are shims between the caps which can be reduced to close up the spindle clearance. The bearings and related oil galleries will surely need cleaning out, and the bearing and journal surfaces evaluated in any case. I'd be inclined to be that with careful setup spindle clearance can be substantially reduced. Regardless, that will be a process of measurement and refinement - which is uniquely appropriate for long winter evenings.
 
You will find work that fits it. It's in the nature of machine tools that we always find a job that pushes them to their limits. If you've got space for it and can spare a little time correcting any problems with it, it'll find a use.
 
When I started I had a 22x84 Swift lathe .....and I did lots of small work on it ..out of necessity .....it had a similar range of threads to a small lathe ,and IIRC ,it was easier to thread with than a lot of small lathes ,as saddle travel is very steady due to weight.
 








 
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