Sheldon Lathe Identification

Yuck!! YUCK!!!

First thing, lets get the leadscrew out. Bump it back the other direction to expose the end of it. Take a flat file and remove any burrs, positive metal from the OD of the leadscrew up to the threads. Next clean out the keyway to remove any crud. After doing that, it should pull out.
Okay, next go review my thread on my 15" rebuild to see some of the repairs I've made to the apron including the rack pinion gear. Also locate the drawing for the rack pinion gear on the Sheldon 2 Group under "My 13" Sheldon Sebastian Lathe". Oh, may as well attached it here too. I also included the drawing for the Worm and end bushings.
Got to run will get back with you in a bit on how the get all of that apart. Ken
 

Attachments

  • 10756-Rack Pinion- R single rod Apron.pdf
    73.6 KB · Views: 14
  • 10720-Worm for R single rod Apron.pdf
    67.3 KB · Views: 9
Ok, on removing the Rack Gear item 22 in the Sheldon manual, first thing, find the 10-32 set screw in the bull gear, item 15. Make sure there are not two in the hole. Once this is done, take a brass drift or punch and drive the shaft out from the front of the apron. Take your time and don't get too carried away driving it out. It should come out without too much force. Once that is done move down to item 20, handwheel pinion, (Sheldon has a typing error in their parts list, they call it a rack pinion, which it is not) remove the set screw item 13, then drive that shaft out from the front. Once that is done, be time to look at your options here for the rack pinion. The bronze bushings I bought off of EvilBay. Their sizes are 5/8" ID x 7/8" OD. One is 7/8 long and the other is around 1-1/4" long that I bought. These are a little longer than the one's that get pulled and I did that on purpose. If you'll notice in my picture posted, I put a longer bushing in front of the apron and let it stick out about 3/8". This gives the shaft a little more support and bearing for the bull gear. I did likewise for the bushing on the backside too. Making these repairs is going to be difficult without access to at least another lathe.

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Wow got everything out of the. gearbox except the worm screw and related bushings. I'm not sure how to remove it other than finding a way to drive it out one side or the other thus removing the bushing and gear, but wanted to ask if there is a better way. The bushing set screws have been removed, just don't want to damage anything. The worm screw outside threads are in pretty good shape, but the inside key is all but gone. don't think it is replaceable, so will have to find one. All other gears are in really good shape considering what was in the gearbox....... I have not taken any parts off the clutch assemblies, as I wanted to check if there are any secrets there... for their disassembly.
I also have a question on the rack pinion. Can the one I have have the gear machined off and install the gear on the old shaft? Thought that might be a bit easier than having to make a new shaft. Old shaft is not worn very much, just the bushings
Also is the worm gear available to purchase from someone? If so where might I find one?
In initial looking at some of the parts the threads on Part # 27 Half nut are quite worn. Might work, but I would say that about 60% of the teath are gone. Same question as the worm gear are they available?
Couple of Pics with initial cleaning of gearbox. all the rest of the parts need cleaning upon final dissassembly.

PS I have tried just about every combination of "My 13 Sheldon Sebastian Lathe" on Yahoo Groups 2 and can only find 3 prints of the parts. any suggestions about how i'm missing it?

Apron Gearbox - Empty - 02.jpg Apron Gearbox - Empty - 03.jpg Apron Left Clutch Assembly.jpg Apron Right Clutch Assembly.jpg Apron Worm Gear.jpg
 
The apron casting cleaned up pretty nice. As removing the worm and bushings, make sure the setscrews are out, which I believe you have already done so. Take a drift, about 1-1/2" OD and drive out the bushing, going from one end. Doesn't matter which end. Once the first bushing is out, remove the worm. Next drive the second bushing in some more until it's drops out to the inside.

Ok, as for finding a new worm gear, I have not found one yet without going to B & K and buying it from them. I suspect, it'll cost you as much as you paid for the lathe when you bought it. I'm guessing around $800-1100 for the worm. Not including the bushings, which I would guess at $100 apiece. Now, what you could do is broach a shallow keyway in the bore of the existing worm and either silver solder a new key in place or pin one in place. I've been lucky not to repared one in my past. I have done this on other lathes in my past that I repaired. I notice the worm is not centered in the middle of the housing when assembled in your picture. When it goes back together, end play should be around .010-.025" and in the center. Might keep that in mind for later. I would encourage getting a hold of B & K and see what they can do for you on this as well as for the rack pinion too.

Going back to the rack pinion, You can turn down the existing gear off and press fit the new gear on. I find it easier to make a new shaft, but doing this, requires a mill to cut the new keyways.
 
I attached the drawings for the worm and rack gear in post #21. If you need drawings for any of the other parts in the apron, let me know, I'll be glad to provide them.

The clutches for the carriage and cross feed looked to be in good shape. Unless, there is pieces of the wavey springs dropping out, I would leave them alone. If you insists to take them apart, the is a certain sequence of disassembly. On the backe end of the clutch assembly, there is a round threaded nut that is PINNED in place by a very small roll pin. It is very easy to miss. Did this twice! and really messed up some things. Remove the solid rod that rides in the ID of the shaft. That shaft is a anti engagement mechanism that keeps you from engaging the half nuts and feed clutches at the same time. So, going back together, make sure they get re-installed. Once removed, take a small drive punch and drive the roll pin into the ID of the shaft. Ther is only one of these pins per shaft. Once removed, back off the nut, right hand threads, the nuts are a slight interference fit too. Once the nut is off, the rest of the clutch can be taken apart.

As for the half nuts, See what a new set is going to cost you. It may be your only way of fixing the old. I'll attach the half nut drawing for reference.

Ken
 

Attachments

  • 10703-1-Half Nut Set- R single rod Apron.pdf
    73.9 KB · Views: 8
4gsr said:
I attached the drawings for the worm and rack gear in post #21. If you need drawings for any of the other parts in the apron, let me know, I'll be glad to provide them.

The clutches for the carriage and cross feed looked to be in good shape. Unless, there is pieces of the wavey springs dropping out, I would leave them alone. If you insists to take them apart, the is a certain sequence of disassembly. On the backe end of the clutch assembly, there is a round threaded nut that is PINNED in place by a very small roll pin. It is very easy to miss. Did this twice! and really messed up some things. Remove the solid rod that rides in the ID of the shaft. That shaft is a anti engagement mechanism that keeps you from engaging the half nuts and feed clutches at the same time. So, going back together, make sure they get re-installed. Once removed, take a small drive punch and drive the roll pin into the ID of the shaft. Ther is only one of these pins per shaft. Once removed, back off the nut, right hand threads, the nuts are a slight interference fit too. Once the nut is off, the rest of the clutch can be taken apart.

As for the half nuts, See what a new set is going to cost you. It may be your only way of fixing the old. I'll attach the half nut drawing for reference.

Ken
Click to expand...
Thanks again for the great information. Do you have any more information on B & K as a google search is filled with numerous B & K that have nothing to do with Lathe Parts and those that do are selling complete lathe's
Anything from Burger King to Pharmacuticals......
I think based on what you indicated previously that I will leave the clutches alone, just clean them up as they were functional before I removed them.
With ref to the worm gear spacing it appears that the bushings are out some on each end about .250 or more. not sure if they were that way before I removed the set screws..... they may have pushed out some when I was trying to remove the drive shaft. I will check that out later today as I have a lot of parts to clean up and had to change the parts cleaner. I ran the auto parts shop out of parts cleaner and need to get some more so back to town.
Again thanks for the prints. I am still only able to see about 6 prints on Yahoo groups. the screen shot below is the only hits i get. This is with Sheldon Sebastain Lathe as a search then ken's 13Yahoo Groups Screen.jpg
 
One of the problems with both the Yahoo and the eBay search engines is that they ignore punctuation symbols. So B&K gets searched as B K. It'll find B&K but it'll also find things like

SONY A1118098B K BOARD MODEL# KDL-V32XBR1

WRT Yahoo FILES, running the search engine, unlike most others, requires pressing the Enter key after entering your search string. In most search engines, there is a SEARCH button to the right of the entry field. And you can either click there with the mouse or press the ENTER key. For whatever reasons, my muscle memory wants to do the former. Which gets you into all sorts of confusion on Yahoo as there is no SEARCH button to click on..If I absent mindedly click on the button to the right, it searches all GROUPS.

The other problem that I have found on Yahoo is that, with only two exceptions that I know of, none of the Moderators or Owners there make any effort to enforce any logical file naming standards and there is no organization of files into any symblance of order. They are all just left wherever and however the originator made them.
 
You found the correct address. Sorry, I should have added a link for their contact information.
 
4gsr said:
I attached the drawings for the worm and rack gear in post #21. If you need drawings for any of the other parts in the apron, let me know, I'll be glad to provide them.

The clutches for the carriage and cross feed looked to be in good shape. Unless, there is pieces of the wavey springs dropping out, I would leave them alone. If you insists to take them apart, the is a certain sequence of disassembly. On the backe end of the clutch assembly, there is a round threaded nut that is PINNED in place by a very small roll pin. It is very easy to miss. Did this twice! and really messed up some things. Remove the solid rod that rides in the ID of the shaft. That shaft is a anti engagement mechanism that keeps you from engaging the half nuts and feed clutches at the same time. So, going back together, make sure they get re-installed. Once removed, take a small drive punch and drive the roll pin into the ID of the shaft. Ther is only one of these pins per shaft. Once removed, back off the nut, right hand threads, the nuts are a slight interference fit too. Once the nut is off, the rest of the clutch can be taken apart.

As for the half nuts, See what a new set is going to cost you. It may be your only way of fixing the old. I'll attach the half nut drawing for reference.

Ken
Click to expand...
ok is there some secret to getting out the roll pin on the cross feed clutch. i have tried damn near everything. broken several drills. bent several drifts and still have done little to remove the roll pin. Stopped today as frustration is setting in. thought of heating it a bit, but ........
 
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