Magnetic chuck project

[mac1911]

Picked up this chuck a while back for scrape price. It worked but just not 100% I did get it apart and found its just not traveling that last bit to get the plates lined up correctly.
I am not a machinist and often these small jobs can be frustrating as how to approach a repair on this.
Now that I have a 4 jaw I was thinking of machining the crank assembly
Another approach was to mill off the worn stub and make a press fit replacement and braze it in place? Or green loctite.
It will be a lightly used tool

I did get a price list from walker. The $$$ spent to fix it will go better towards tools and time learning to fix it
HANDLE ASSY P/N 58-BB984-??SP $125 EACH ( chuck size needed to complete part number)

CRANKSHAFT P/N 39-DD999 $ 160 EACH

BUSHING P/N 39-DD2327 $ 25 EACH

CAMLINK P/N 44-DXMY777 $ 80 EACH

INTERNAL SPRING P/N 39-DXMY635 $ 10 EACH

SEAL P/N 39-DD1222 $ 15 EACH

 

[Nutfarmer]

Look like you could just bush the link where it rides on the crank.

 

[mac1911]

Look like you could just bush the link where it rides on the crank.

So machine whats left of the stub round and add a bushing to the cam?
Im wondering if whats left of the stub will be strong enough.

 

[mac1911]

So im looking at the other parts on the chuck. The bearing looks to be a blind hole press fit. I would like to get the ild bearing out in one piece.
I cant tell what material the bushing is made from. I can only assume softer steel than the crank that runs through it.

Any tips on getting this out in one piece?

 

[durableoreo]

If the main problem is the link with the "wallered out" hole, I'd just drill it out and add a bushing. Like Nutfarmer said. Cleaning up the pin on the crank shaft should be easy in a 4-jaw. The trick is finding the correct center because wear isn't usually symetric. But it looks like you have prints, so you'll have more clues. If you fix those two parts, it will save hundreds of dollars. I would buy the seal and spring, though.

 

[mac1911]

If the main problem is the link with the "wallered out" hole, I'd just drill it out and add a bushing. Like Nutfarmer said. Cleaning up the pin on the crank shaft should be easy in a 4-jaw. The trick is finding the correct center because wear isn't usually symetric. But it looks like you have prints, so you'll have more clues. If you fix those two parts, it will save hundreds of dollars. I would buy the seal and spring, though.

The crank is fubar the link not so much. I will get the pin gauges out and give it a closer look.
There is part of the original pin diameter left ( does not show in picture)

The bushing through the body is worn , I would like to replace it.

The springs sit in the bottom they appear fine , maybe order them after I get the linkage squared away.

The seal is of no worry , looks like a oring. This old chuck will see light use, no fluids or heavy grinding dust.

 

[mac1911]

Theres just a touch of the original dia left so going to wing it and center up best I can

 

[mac1911]

Sorry no pictures , I started on a new crank . I have no idea what Im doing but each step starts looking like the part I need , lol

 

[mac1911]

So a warm enough weekend to get out in the shop.
Trying to make a new crank for magnetic chuck. Figure it would be good practice for the 4 jaw.
I think I might have missed my mark and not sure I have enough material to space the opposite side shaft? Still not sure how to best lay out the other shaft.

 

[Cadillac]

I think it would have been easier doing the offset journal in a second ops. Chuck your material and cut that diameter with the cross hole. Then put in 4jaw side you just cut in jaws. Offset material in chuck whatever that number is. Then cut that major diameter and the other side. Cut off excess done.
With how you cut the offset first you will have to flip the part, re-offset your offset to cut on center of the material. Then cut your shaft. That make sense?