# 420-TN Lathe Rebuild



## bull schmitt (Jul 1, 2013)

I originally posted this to the "Show Us Your South Bend Lathe" but one of the members suggested, because it is somewhat unusual, that I post it where others might view it. The model is actually 420-TN.  It was made in the Fall of 1935, Serial Number 60410. I have been told it is a Toolmakers Model.


It was a basket case when I bought it and I am still restoring it .I still have a few misc parts to locate. Hope to have it in operation shortly.



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## genec (Jul 1, 2013)

nice job, not trying to be a wise guy but did you cut part of it off? I don't think I have seen one that short before. it will still do 99% of what you do.


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## bull schmitt (Jul 1, 2013)

Nope I didn't cut it off.:lmao:

The bed is 25 inches. Probably called a 24 incher.


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## itsme_Bernie (Jul 1, 2013)

Absolutely, totally cool...  What spindle does it have?  What collets does it take?  Wow



Bernie


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## ScrapMetal (Jul 2, 2013)

I want one for the center piece on our dining room table! :biggrin: (Actually, I'd probably put it next to the television.)

Very cool little lathe and it looks like you've done a great job getting it back in shape.

-Ron


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## woodtickgreg (Jul 2, 2013)

I've never seen one before, looks really cool. a unique piece for sure.


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## pineyfolks (Jul 2, 2013)

I like it. Your next purchase might be a set of screw machine drills to match it!


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## bull schmitt (Jul 3, 2013)

I need a little info. The spring/detent that retains the pin in the bull gear is missing. The pin is there and a "cover" of sorts is on the gear. I see notches on the pin but have no idea what the missing parts look like. Can anyone describe what is missing?


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## woodtickgreg (Jul 3, 2013)

A pic of what you have might be helpful.


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## macrnr (Jul 3, 2013)

bull schmitt said:


> I need a little info. The spring/detent that retains the pin in the bull gear is missing. The pin is there and a "cover" of sorts is on the gear. I see notches on the pin but have no idea what the missing parts look like. Can anyone describe what is missing?


try this


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## woodtickgreg (Jul 3, 2013)

I think what you are looking for is on page 9.


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## bull schmitt (Jul 3, 2013)

That manual helps a lot.  I believe the part I need to find or make is number 41 on page 5!!


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## sandama171 (Jul 7, 2013)

The way the Apron assy looks (Square) and the headstock yes it is a 9" model however a Junior model, keep that in mind parts are hard to come by for this puppy I own one too, 9 x 48 junior model.
none of the 1938's and up 9" model parts will fit this lathe, just trying to save you some headaches.
the bed with in the junior models is wider and the spindle is smaller than the newer 9" models. 
the light 10K or the heavy 10 also some parts will fit but other won't so be careful before you buy anything for it.
take care and good luck.
Also the manual provided here is for the newer model.


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## bull schmitt (Jul 8, 2013)

sandama171,

Thanks for the info about the 420-TN being the same size as a JR model. This could save me a lot of $$$.
hew:
BTW I got the lathe running today and made some chips!!)


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## RRBud (Jan 27, 2015)

sandama171 said:


> The way the Apron assy looks (Square) and the headstock yes it is a 9" model however a Junior model, keep that in mind parts are hard to come by for this puppy I own one too, 9 x 48 junior model.
> none of the 1938's and up 9" model parts will fit this lathe, just trying to save you some headaches.
> the bed with in the junior models is wider and the spindle is smaller than the newer 9" models.
> the light 10K or the heavy 10 also some parts will fit but other won't so be careful before you buy anything for it.
> ...



At last someone who knows about these rare birds. I have a 420 YN toolmaker  9 x 36 and have been hunting information and a few parts for years. I found out the hard "$$$$" way that the parts for this are not the same as a 9 " workshop. Can you help me with info on the Back Gear. Can't find a parts list that shows it and its part #. Would this be interchangable with the 9" junior or 10K? Its hard to ask for something when you don't know where to look. My Back gear was missing when I got the lathe but the shaft and eccentric are intact. Thanks in advance for any information you may have. RRBud


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## RRBud (Jan 27, 2015)

bull schmitt said:


> I originally posted this to the "Show Us Your South Bend Lathe" but one of the members suggested, because it is somewhat unusual, that I post it where others might view it. The model is actually 420-TN.  It was made in the Fall of 1935, Serial Number 60410. I have been told it is a Toolmakers Model.
> 
> 
> It was a basket case when I bought it and I am still restoring it .I still have a few misc parts to locate. Hope to have it in operation shortly.
> ...


I just found your post and picture. Looks like a dwarf version of my 420 YN , 4 x 36 Toolmaker. As far as parts go what have you found out which they the same as? 9 JR or 10 K keep coming up. is this true? Having a difficult time finding a back gear for mine . Any help will be appreciated......RRBud


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## thomas s (Jan 27, 2015)

Wow that is one cool little lathe.


 	 		 			:thumbzup3:


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## bull schmitt (Jan 29, 2015)

RRBud said:


> I just found your post and picture. Looks like a dwarf version of my 420 YN , 4 x 36 Toolmaker. As far as parts go what have you found out which they the same as? 9 JR or 10 K keep coming up. is this true? Having a difficult time finding a back gear for mine . Any help will be appreciated......RRBud



This is the first and only SB lathe I have ever had so I don't know much about all the various models. Parts I have founds so far: belt tension handle, new nuts for the cross feed and compound, tool post, tool holder and replaced screw portion of compound. I have not done anything with the back gearing as I only have a very few gears. No collets or collet holder (will probably get one). If you know what you are looking for there are a lot of parts on eBay. This continues to be a work/love in progress!:thumbsup:


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## RRBud (Jan 29, 2015)

bull schmitt said:


> This is the first and only SB lathe I have ever had so I don't know much about all the various models. Parts I have founds so far: belt tension handle, new nuts for the cross feed and compound, tool post, tool holder and replaced screw portion of compound. I have not done anything with the back gearing as I only have a very few gears. No collets or collet holder (will probably get one). If you know what you are looking for there are a lot of parts on eBay. This continues to be a work/love in progress!:thumbsup:


Thanks for the response. my 420 YN is exactly like yours only longer bed 36". I am desperate for info on the back gear. Been looking for over five years and other than yours have only seen one other on the net. Could I possibly get some pictures of your bull gear setup and some dimensions on the gears,toothcount,width, overall length of the gear piece and ID of the shaft bore? I realize this is a lot to ask for I'm down to asking for one by description. Also where did you source the cross feed and compound? Any help will be greatly appreciated.   RRBud


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## bull schmitt (Jan 30, 2015)

RRBud said:


> Thanks for the response. my 420 YN is exactly like yours only longer bed 36". I am desperate for info on the back gear. Been looking for over five years and other than yours have only seen one other on the net. Could I possibly get some pictures of your bull gear setup and some dimensions on the gears,toothcount,width, overall length of the gear piece and ID of the shaft bore? I realize this is a lot to ask for I'm down to asking for one by description. Also where did you source the cross feed and compound? Any help will be greatly appreciated.   RRBud



I will try and get some of those measurements for you. My lathe is in an unheated garage and it is colder than a witch's tit here so it may be a while before I can get around to collecting the data.


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## bull schmitt (Mar 14, 2015)

RRBud,

It finally warmed up enough to go out in the shop!!  Here is some info for you:
Bull Gear:
   Dia 5.25
   Width .675
   Teeth 71
Back Gear:
   Dia. 5.0
   Width .60
   Teeth 66 
Rack Length 9.5
Bore ID .765

Couple photos:


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## lugnard (Mar 15, 2015)

Very interesting lathe to say the least. What size are the spindle threads on it?
1 1/2-8?

Harry


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## bull schmitt (Mar 28, 2015)

lugnard said:


> Very interesting lathe to say the least. What size are the spindle threads on it?
> 1 1/2-8?
> 
> Harry



Yes they are 1 1/2 -8 thread.


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