Big Lathe Broke, So Ya Gotta Fix It.

[jackieschmidt]

One my Machinist ran me down and said that the 28ft LeBlond would not shift from high range to low range.

We pulled the top cover off, and found a broke shifting fork. It seems it had already been broke in a previous life and brazed back together.

We figured the best bet would be to make one, out of steel. Where it rides against the gear collar, we could overlay it with phosphorous bronze weld.

So, I fabricated a new fork, got it fitted in, and it works great.

This is what you have to do with ‘60’s vintage machines.

here are some pictures. The final one of my new shifting fork was taken just after I had done the final fitting, but before I had deburred it. But you get the idea.

 

[Dusty Stevens]

You ought to weld that one back together after you grind all the brazing rod off. Thats just simple cast iron. Any of your local welding shops will have the stuff to do it

 

[AlNyhus]

That'll keep it going for the grandkiddos years down the road, Jackie. Looks like a good amount of room to work in there, fortunately. Tell me about those rivet-head cap screws?????

Randy Robinett was into the gear box on his lathe quite a bit a few months back. True to form, he not only fixed the problem but did quite a few tweaks that improved it's performance....I now call him 'Lord Grizzly'.

When he sent me the pics of the gear box internals, I told him it looked just like the Liberty clutchless 5 speed in the Competition Eliminator car I crew on.

Good shootin' -Al

 

[liljoe]

Hey Jackie,
Those guys are lucky to have a maintenance man around with your talent.
Joe

 

[urbanrifleman]

I should have taken a picture inside the gearbox of my Standard Modern. The oil is as clear as water and the gears are like brand new. The bearings look like they were just installed.

 

[Sniperhandle]

That looks like 90 wt gear oil in the old LeBlonde.

 

[shortgrass]

Ya' can't always call a technician or mechanic to fix what's not working. It doesn't even have to be 1960s vintage to no longer have support. Good fix, Jackie! That put that lathe back into doing what needs done! Let's hope something was learned by the guys in the shop.

 

[Carl S]

Looks a good job Jackie.depending what grade of cast iron it is it could have been welded with cast electrodes,tig welded or forge welded.forge welded would be the best way.

 

[jackieschmidt]

I could have brazed it back together, but said what the heck, make one out of steel and solve the problem. As I said, we did put phosphorous bronze weld where the sides of the fork ride against the gear.

I made the rivets. It makes for a more secure mount on the actuator rod.

 

[paperpuncher]

Fortunate that that broken fork did not foul up the gear train Looks like it could have gotten tangled up

 

[jackieschmidt]

Well, after we got the Leblond up and running, it quit feeding.

After diagnosing every conceivable problem, we came to the conclusion that the key that the main feed rod engages in the carriage might be sheared.

Sounds simple, except in order to get to it, you have to drop the apron off the carriage. That entails unhooking the lead screw and main feed shaft and pulling them out of the apron, then removing all of the bolts and Howe ring the apron. The entire assembly probably weighs 500 lbs.

We found the problem, the 4 inch long key was sheared. We also found some other badly worn parts. The 10 inch long bushing that the lead screw runs through Irving it support was worn through.(old age got it). Also, the fork that shifts the carriage feed gears from forward to reverse was worn pretty bad.

I spent part of yesterday and today making a new bronze bushing from 660 bronze and a new shifting fork from naval bronze.

We are trying to find a key from new old stock, if nobody has one, I will have to make one from S-7 tool steel and have it heat treated.
Here are a few pictures of our progress so far, the new bushing and shift fork installed.

 

[Judd]

That sounds like a Monday.

 

[Adam in WI]

When it rains, it pours eh?

 

[Dusty Stevens]

Should a key be that hard? In all my days as a maintenance man keys were always softer than the material they protect. A hard key will shear and tear the keyways up. A regular key will shear and each piece will spin in its slot and not wear or tear the shaft.

 

[jackieschmidt]

Should a key be that hard? In all my days as a maintenance man keys were always softer than the material they protect. A hard key will shear and tear the keyways up. A regular key will shear and each piece will spin in its slot and not wear or tear the shaft.

The original is pretty hard. A file skates over it.

 

[jackieschmidt]

I went on ahead a made a key out of a piece of Chrome Moly 4142 at around 42 RC. I used a drop off of a piece we used to make some coupling bolts a while back.

Got it all back together. Everything works great.

 

[hdskip]

Jackie, you are a man after my own heart. I told people many times "Well this is a machine shop isn't it and I am a machinist last time I checked".

 

[Retired shooter]

One my Machinist ran me down and said that the 28ft LeBlond would not shift from high range to low range.

We pulled the top cover off, and found a broke shifting fork. It seems it had already been broke in a previous life and brazed back together.

We figured the best bet would be to make one, out of steel. Where it rides against the gear collar, we could overlay it with phosphorous bronze weld.

So, I fabricated a new fork, got it fitted in, and it works great.

This is what you have to do with ‘60’s vintage machines.

here are some pictures. The final one of my new shifting fork was taken just after I had done the final fitting, but before I had deburred it. But you get the idea.View attachment 1410039View attachment 1410045View attachment 1410051

Hey. the original brass repair on the linkage was a good repair, did not break in the repair, but next to it in the cast. No telling how many years the repair lasted.

Nice job on the repairs.

 

[Pawnee Bill]

Well done!!

 

[thebeav]

Very nice work !