Made a replacement Logan 200 cross feed nut

[expressline99]

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

• expressline99
• Oct 3, 2017

Full View Logan 200 Cross Feed Nut

• expressline99
• Oct 3, 2017

Top View Logan 200 Cross Feed Nut

• expressline99
• Oct 3, 2017

Bottom View Logan 200 Cross Feed Nut

• expressline99
• Oct 3, 2017

Paul

 

[RandyM]

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

 

[expressline99]

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

 

[Silverbullet]

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.

 

[Bob Korves]

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.

 

[expressline99]

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

 

[expressline99]

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

 

[Bob Korves]

.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.

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.

 

[wileyone123]

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?

 

[4GSR]

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?