# Made a replacement Logan 200 cross feed nut



## expressline99 (Oct 4, 2017)

I finished up making a replacement cross feed nut today. 660 Bronze 7/16-10 tpi Acme Left handed threads.
I used a 3/8" corner rounding mill to round the edges. Yes, I know I went a little deeper on one side.

I hand tapped it while it was mounted in the mill vise. I don't own a Jacobs chuck that fits the mill...so I used a 3/4" diameter (on the end of the shank) spring loaded center punch in an R8 collet to keep tap straight while tapping. The spring tip (if you don't set it off) will keep tension on the tap as you move down. It might sound precarious but if you set it up right it will be ridged enough to keep you straight. You will have to feed your quill down as you go...since a spring punch has limited movement. Since tapping Acme threads moves a lot of metal I made sure to break the chip every quarter turn. The tap I used was a single pass through tap.

Gotta make the screw for it later on.













Side View Logan 200 Cross Feed Nut



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Full View Logan 200 Cross Feed Nut



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Top View Logan 200 Cross Feed Nut



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Bottom View Logan 200 Cross Feed Nut



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Paul


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## RandyM (Oct 4, 2017)

Well done! Feels good, doesn't it Paul?


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## expressline99 (Oct 4, 2017)

RandyM said:


> Well done! Feels good, doesn't it Paul?



It's wonderful. Excited to make replacement parts myself. There really is a lot to be said about learning and doing it. 

Paul


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## Silverbullet (Oct 4, 2017)

Now my question , did you make a spare , anytime I make a wear item I try to make up extras and hang them over or under the machine it fits. I'm planning on going over my logan asap. But the back surgery first. The removal of the inerstem devise is on the 18th of October then mri and back to surgeon. You did a good job on the part the extra lip don't mean squat.


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## Bob Korves (Oct 4, 2017)

Nice, Paul!  Test the shaft as you cut the threads until it just turns smoothly in the nut threads.  Pay no attention to the actual finish diameter number, so long as the thread pitch is correct.  You will also need some way to adjust backlash out of the screw/nut, both in the beginning and as the parts wear with time.


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## expressline99 (Oct 4, 2017)

Silverbullet said:


> Now my question , did you make a spare , anytime I make a wear item I try to make up extras and hang them over or under the machine it fits. I'm planning on going over my logan asap. But the back surgery first. The removal of the inerstem devise is on the 18th of October then mri and back to surgeon. You did a good job on the part the extra lip don't mean squat.



I didn't make a replacement. But it would be easy after doing this one.  The rounding as you probably know is only for clearance in the casting. But I figured someone would see it.    I've already got a rough milled piece of bronze for making the compound feed nut. So I may do that next before making the screw.  I do have one issue on making the screw....gotta get a couple of t-slot mill cutters for the woodruff keys. I have no experience with those so brands/types suggestions are welcome. 

Sorry about your back surgery. My wife had her back surgery about 3 months ago on L5-S1 She is still doing physical therapy and that might go on for a year. But she is moving around just fine. Seems to have helped quite a bit.  

Thanks for the support. I really love doing this stuff. 

Paul


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## expressline99 (Oct 4, 2017)

Bob Korves said:


> Nice, Paul!  Test the shaft as you cut the threads until it just turns smoothly in the nut threads.  Pay no attention to the actual finish diameter number, so long as the thread pitch is correct.  You will also need some way to adjust backlash out of the screw/nut, both in the beginning and as the parts wear with time.



Thanks Bob!  I actually finished one thing(Part) on my list! I have no idea at all how I will adjust backlash on this? The lathe is all setup for 10 TPI now. Since it takes me forever to change the gears due to inexperience. It will probably stay that way until I make this screw and the one for the compound.  So how in the world would I make something that controls backlash for this lathe? Maybe something in the bushing/dial/handle area?

Paul


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## Bob Korves (Oct 4, 2017)

expressline99 said:


> .gotta get a couple of t-slot mill cutters for the woodruff keys.


T-slot cutters and Woodruff key cutters are completely different animals from each other.  They just look sorta alike.  I have a decent assortment of Woodruff key cutters.  Bring the screw down and we can cut the seat here.


expressline99 said:


> The lathe is all setup for 10 TPI now. Since it takes me forever to change the gears due to inexperience. It will probably stay that way until I make this screw and the one for the compound. So how in the world would I make something that controls backlash for this lathe? Maybe something in the bushing/dial/handle area?


It is critical that the lead screw has precisely 10 TPI, but the diameter and thread form can be cut to fit the nut.  We can talk about options for mitigating backlash the next time I see you.  There are multiple common ways to do so, but it depends on what all you have there now.


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## wileyone123 (Oct 5, 2017)

Nice job on the nut....just purchased a tap to make 1 for mine as well....as the OE nut is cast iron on mine and fairly worn.

Just wondering, Pros/Cons for making a nut out of Brass VS Bronze?


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## 4GSR (Oct 5, 2017)

All man Paul.  You take all the fun out of using a tap for cutting 7/16-16 Acme LH nut thread.  I single pointed the thread in the nut I have on my 9"SBL.  Of course, I was much younger and sharper at cutting the thread then than I am now.  Still have the boring bar and chunk of tool steel I sharpen to cut the thread, too.
BTW- Nice job! What class of fit is the tap you used?


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## expressline99 (Oct 5, 2017)

4gsr said:


> All man Paul.  You take all the fun out of using a tap for cutting 7/16-16 Acme LH nut thread.  I single pointed the thread in the nut I have on my 9"SBL.  Of course, I was much younger and sharper at cutting the thread then than I am now.  Still have the boring bar and chunk of tool steel I sharpen to cut the thread, too.
> BTW- Nice job! What class of fit is the tap you used?



2g but I will be of course single pointing the 1-1/4" 5tpi for the Bridgeport  I didn't feed like I could grind a tool to do this nut.  Thanks I'm getting better as I go 
Paul


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## 4GSR (Oct 5, 2017)

Yeah, that class 2G tap is design to give you a sloppy fit.  But since you are going to make a screw, you can fit the nut to the screw thread and get to a snug close fit.


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## expressline99 (Oct 5, 2017)

4gsr said:


> Yeah, that class 2G tap is design to give you a sloppy fit.  But since you are going to make a screw, you can fit the nut to the screw thread and get to a snug close fit.



I will do that for sure. I'll keep testing as I cut to get it tight.  Are the originals on machines cut to 3g fit?


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## 4GSR (Oct 5, 2017)

The originals were more or less cut to a 3C fit, not 3G.  Now, I've really confused you. Sorry.


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## expressline99 (Oct 5, 2017)

4gsr said:


> The originals were more or less cut to a 3C fit, not 3G.  Now, I've really confused you. Sorry.



They were centralizing thread standard?


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## 4GSR (Oct 6, 2017)

Correct!


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## expressline99 (Oct 6, 2017)

wileyone123 said:


> Nice job on the nut....just purchased a tap to make 1 for mine as well....as the OE nut is cast iron on mine and fairly worn.
> 
> Just wondering, Pros/Cons for making a nut out of Brass VS Bronze?



I'm not a pro at metallurgy (there are several around here)  A couple of things I do know bronze is stronger than brass and more resistant to corrosion. Although bronze is quite a bit more expensive than brass. Bronze will probably last longer.  But back to hobby usage either might last longer than us.  Oh one more thing at some point I had read that brass is subject to "stick slip" during use and can make it difficult during fine adjustments.  Anyhow, the main reason I chose bronze was because of it being a stronger material. Someone else will jump in here and correct anything I messed up I hope. 

Paul


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## Bob Korves (Oct 6, 2017)

There are many types of brass and many types of bronze, all with different characteristics.  They cannot really be compared generically.


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## Silverbullet (Oct 7, 2017)

expressline99 said:


> I didn't make a replacement. But it would be easy after doing this one.  The rounding as you probably know is only for clearance in the casting. But I figured someone would see it.    I've already got a rough milled piece of bronze for making the compound feed nut. So I may do that next before making the screw.  I do have one issue on making the screw....gotta get a couple of t-slot mill cutters for the woodruff keys. I have no experience with those so brands/types suggestions are welcome.
> 
> Sorry about your back surgery. My wife had her back surgery about 3 months ago on L5-S1 She is still doing physical therapy and that might go on for a year. But she is moving around just fine. Seems to have helped quite a bit.
> 
> ...


Woodruff cutters are a really great keyway system , having the right cutter isn't hard to cope with or find.. Once you know the width and depth it's just center it and cut to depth . There easy to center to , a piece of paper held till it pulls it or cuts is one side , then the other side ,, usually top n bottom on Bridgeport style mill. Horizontal is sides. After you know the center just half the width and the cutter half of width figured in. Just lock up the tables and slow feed with cutting oil.


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## craze8t8 (Nov 24, 2017)

expressline99 said:


> It's wonderful. Excited to make replacement parts myself. There really is a lot to be said about learning and doing it.
> 
> Paul


Do you happen to have the dimensions for the carriage/saddle locknut and bolt?


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## expressline99 (Dec 4, 2017)

craze8t8 said:


> Do you happen to have the dimensions for the carriage/saddle locknut and bolt?


I'll have to check and see if I can get that for you. I can always pull them off and try to measure for you and take a couple of pictures.
Give me some time. Really busy over here. (hard to get time to play!) 

Paul


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## benmychree (Dec 4, 2017)

Silverbullet said:


> Woodruff cutters are a really great keyway system , having the right cutter isn't hard to cope with or find.. Once you know the width and depth it's just center it and cut to depth . There easy to center to , a piece of paper held till it pulls it or cuts is one side , then the other side ,, usually top n bottom on Bridgeport style mill. Horizontal is sides. After you know the center just half the width and the cutter half of width figured in. Just lock up the tables and slow feed with cutting oil.


I cut a flat with the cutter until it is the same width as the cutter, and eyeball the cutter central on the flat; the flat also is the zero point for the depth of the keyway; Machinery's Handbook has a table of depth for all the different numbers/sized of woodruff keys, I Zeroxed the page, glued it to cardboard, and posted it on the wall next to the milling machine.


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## benmychree (Dec 4, 2017)

4gsr said:


> All man Paul.  You take all the fun out of using a tap for cutting 7/16-16 Acme LH nut thread.  I single pointed the thread in the nut I have on my 9"SBL.  Of course, I was much younger and sharper at cutting the thread then than I am now.  Still have the boring bar and chunk of tool steel I sharpen to cut the thread, too.
> BTW- Nice job! What class of fit is the tap you used?


I had an American "High Duty" lathe, built about 1916, all geared; the cross feed not was quite worn out, it was 3/4 - 5 square thread, left hand, of course; I made a new nut of cast iron and about 3" long with acme thread and made a new screw; yes, I still have the boring bar and tool from about 45 years ago; the cast iron nut is very long wearing compared to bronze, and I think holds lubrication better than bronze, and I would never consider using brass, it does not wear well.


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## eeler1 (Dec 4, 2017)

Hi Paul, tired of changing gears, are you?  Look here;

https://sacramento.craigslist.org/tls/d/logan-lathe/6400499500.html

Was asking $1000, now $500, and all of your tooling will interchange with it.  Just a thought, I have no relationship to the seller.  Just I'm in west sac, and see this frickin ad every time Iook at CL.  So, either you buy it (offer him less), or I have to stop looking at CL.


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## expressline99 (Dec 15, 2017)

eeler1 said:


> Hi Paul, tired of changing gears, are you?  Look here;
> 
> https://sacramento.craigslist.org/tls/d/logan-lathe/6400499500.html
> 
> Was asking $1000, now $500, and all of your tooling will interchange with it.  Just a thought, I have no relationship to the seller.  Just I'm in west sac, and see this frickin ad every time Iook at CL.  So, either you buy it (offer him less), or I have to stop looking at CL.



I missed it! Awww. I didn't get an email from HM showing this reply! 

Paul


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## expressline99 (Dec 15, 2017)

craze8t8 said:


> Do you happen to have the dimensions for the carriage/saddle locknut and bolt?


I feel bad about this! Forgot all about it. Did you ever get the measurements you needed?

Paul


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## 4GSR (Dec 16, 2017)

benmychree said:


> I had an American "High Duty" lathe, built about 1916, all geared; the cross feed not was quite worn out, it was 3/4 - 5 square thread, left hand, of course; I made a new nut of cast iron and about 3" long with acme thread and made a new screw; yes, I still have the boring bar and tool from about 45 years ago; the cast iron nut is very long wearing compared to bronze, and I think holds lubrication better than bronze, and I would never consider using brass, it does not wear well.


Ben,

If the cast iron nut is kept lubricated, it will last a long time as you said.   That is what Sheldon and many other manufactures used for their cross feed nuts.  But the few I've replaced that were cast iron, both the screw and nut were badly worn.  Had to replace both.  Yeah, the cross feed screw and bronze nut I made for my Sheldon is still like new.  Only has about .005" slop for 38 years!


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