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Advice on disassembling 1945 16x54 American Pacemaker Tail Stock

SeanShanny

Aluminum
Joined
Nov 17, 2021
Location
Shaftsbury, Vermont
Folks,

Recently purchased a 1945 American Pacemaker 16x54 lathe. I have started cleanup and have run into an issue with the tailstock. My tailstock does not look like the drawing in bulletin 20 as it has a lever/cam arrangement on the rear of the unit which seems to be what controls clamping it to the ways. Note there is also a large through bolt that goes through the housing that can also be used to clamp to the ways. I have attached some pictures. I am trying to remove the lever from the shaft that goes the tailstock from front to rear. There is a allen head set screw which came right out. There also appears to be a taper pin but the for life of me it will not budge. I don't want to whack it too hard for fear of breaking something. Any advice on how to remove this? Should I try heat? Do I need to drill it out? Am I totally wrong about what this may be? Also why would there be a set screw and a taper pin, isn't that redundant?

Another question is it possible to retrofit the system that would allow the tailstock to be cranked back and forth, this thing has to weigh more than 200 pounds and requires some serious shoving to move?

Thank you.

--sean
 

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Bullentin 10 from 1941 looks like it:

222.JPG

To drive TS up and down ways, a hand crank with pinion gear. Pinion will use the same rack that drive apron, mounted under front bed way:

1660525624681.png

The parts book from 1949, doesn't seem to show your style TS. Maybe there's an earlier book ?

To drive out taper pins I take a serious and fat drift pin. But I grind the contact point appropriate for taper pin. Then when I hit with hammer it hits real solid. Small drift pins or punches often dont cut it. Once slightly broke loose, then move to a smaller punch.

My last resort is to drill it out, then ream to the next size taper pin. . .

Heat may crack the cast iron part when you are beating with a hammer, I try not to use heat for taper pins.
 
American did like nice tight fits in this sort of case. I've not worked on a Pacemaker but have taken apart two High Duty machines to various degrees and ran into very tight shaft/levers locked by taper pin. In this case I wouldn't be suprised by an allen screw, so once the locking shoe and lever position were setup it would lock them together for a trip over to the drill jig for installation of a taper pin. I did have to drill out a couple, one being installed blind and man that one was a pest.
 
Bullentin 10 from 1941 looks like it:

View attachment 371576

To drive TS up and down ways, a hand crank with pinion gear. Pinion will use the same rack that drive apron, mounted under front bed way:

View attachment 371577

The parts book from 1949, doesn't seem to show your style TS. Maybe there's an earlier book ?

To drive out taper pins I take a serious and fat drift pin. But I grind the contact point appropriate for taper pin. Then when I hit with hammer it hits real solid. Small drift pins or punches often dont cut it. Once slightly broke loose, then move to a smaller punch.

My last resort is to drill it out, then ream to the next size taper pin. . .

Heat may crack the cast iron part when you are beating with a hammer, I try not to use heat for taper pins.
Thank you very much for the additional information. It looks like I have a toolroom version of the lathe based on the info in bulletin 10 which is a bonus I think. I will manufacture an appropriately size drift pin and give that a try and stay away from heat.
 
American did like nice tight fits in this sort of case. I've not worked on a Pacemaker but have taken apart two High Duty machines to various degrees and ran into very tight shaft/levers locked by taper pin. In this case I wouldn't be suprised by an allen screw, so once the locking shoe and lever position were setup it would lock them together for a trip over to the drill jig for installation of a taper pin. I did have to drill out a couple, one being installed blind and man that one was a pest.

The allen key makes sense based on your description. I hope I don't have to drill....
 
Folks,

Recently purchased a 1945 American Pacemaker 16x54 lathe. I have started cleanup and have run into an issue with the tailstock. My tailstock does not look like the drawing in bulletin 20 as it has a lever/cam arrangement on the rear of the unit which seems to be what controls clamping it to the ways. Note there is also a large through bolt that goes through the housing that can also be used to clamp to the ways. I have attached some pictures. I am trying to remove the lever from the shaft that goes the tailstock from front to rear. There is a allen head set screw which came right out. There also appears to be a taper pin but the for life of me it will not budge. I don't want to whack it too hard for fear of breaking something. Any advice on how to remove this? Should I try heat? Do I need to drill it out? Am I totally wrong about what this may be? Also why would there be a set screw and a taper pin, isn't that redundant?

Another question is it possible to retrofit the system that would allow the tailstock to be cranked back and forth, this thing has to weigh more than 200 pounds and requires some serious shoving to move?

Thank you.

--sean
As far as removing the taper pin, I would grind or file both sides of the taper pin flush and then make sure you are on the small side. Sometimes the difference isn’t much and you may have to measure with calipers to be sure. Next grind the tip of a nailset punch to the appropriate size. Then put a block of steal under the handle next to the taper pin being sure not to block the pin. The idea behind all of this is to remove any bounce from the shaft in the handle and the shaft of the punch. The taper pins will usually come out if you can make it rigid enough.
IMG_0507.jpgIMG_0508.jpg
Regarding the tailstock crank, mine must have been missing one at some point someone made one for it. I’ve enclosed some pictures of that. I even have an extra pinion and shaft for this.
 
As far as removing the taper pin, I would grind or file both sides of the taper pin flush and then make sure you are on the small side. Sometimes the difference isn’t much and you may have to measure with calipers to be sure. Next grind the tip of a nailset punch to the appropriate size. Then put a block of steal under the handle next to the taper pin being sure not to block the pin. The idea behind all of this is to remove any bounce from the shaft in the handle and the shaft of the punch. The taper pins will usually come out if you can make it rigid enough.
View attachment 371581View attachment 371582
Regarding the tailstock crank, mine must have been missing one at some point someone made one for it. I’ve enclosed some pictures of that. I even have an extra pinion and shaft for this.
Would you be willing to sell the pinion and shaft? My guess is that I would be able to make the bracket and handle. Thank you for the photos and advice.
 
Would you be willing to sell the pinion and shaft? My guess is that I would be able to make the bracket and handle. Thank you for the photos and advice.
Yes. I was originally going to make a different bracket which would have required a little longer pinion. But like many things, when I used the one that was on the machine, I decided it worked well enough. Just send me a PM.
 
For really PITA tapered pins, I have had pretty good luck drilling and tapping the big end of the pin for the largest thread that will fit but still leave a little wall thickness. Then stack up some washers or a small socket over the end of the pin and thread a bolt into the pin. Tighten it, and as you do, tap the opposite end with the hammer and punch - this will either pull the pin or snap off the bolt. If it snaps off you can try hitting the pin real quick with an O/A torch just long enough to get it hot as hell but not the cast iron so much. Then try the bolt in the pin again. If that doesn't work you're pretty well stuck drilling it all the way out.
 
Folks,

Recently purchased a 1945 American Pacemaker 16x54 lathe. I have started cleanup and have run into an issue with the tailstock. My tailstock does not look like the drawing in bulletin 20 as it has a lever/cam arrangement on the rear of the unit which seems to be what controls clamping it to the ways. Note there is also a large through bolt that goes through the housing that can also be used to clamp to the ways. I have attached some pictures. I am trying to remove the lever from the shaft that goes the tailstock from front to rear. There is a allen head set screw which came right out. There also appears to be a taper pin but the for life of me it will not budge. I don't want to whack it too hard for fear of breaking something. Any advice on how to remove this? Should I try heat? Do I need to drill it out? Am I totally wrong about what this may be? Also why would there be a set screw and a taper pin, isn't that redundant?

Another question is it possible to retrofit the system that would allow the tailstock to be cranked back and forth, this thing has to weigh more than 200 pounds and requires some serious shoving to move?

Thank you.

--sean
You have the quick clamping (lever operated) style of tailstock. The 1941 bulletin indicates that it is standard on the 14" & 16" Tool Room Lathes so I'm guessing that you probably have a Tool Room model or a special order tailstock.
 
The tailstock on my 14" squarehead Pacemaker has the crank. I can't imagine using the lathe if it didn't. The late style tailstocks are atleast double the size of the art deco Pacemakers. Thing's gotta weigh 450 lbs.
 








 
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