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Crank Taper Pin won't go back in!

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cadsculptor

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Hi Forum, I have a puzzle for you. I removed the belt tensioning crank from my South Bend 10L lathe for repairs. Needless to say, It took a bit of effort to punch the taper pin out.
I repaired the crank and reinstalled the tensioning mechanism. Now the taper pin holes in the Handle and the tension mechanism don't line up.
The crank was broken a while back in transport. I pressed out the "knob", bored and tapped holes for 1/4-20 cap screws and used some JB Weld in the joint.Everything is solid.
I thought the handle may have been reversed but, installed backwards, the holes in shaft and crank still don't line up.
...I restored a Heavy 10 a while back so this is my second "rodeo". ;-)

I am totally flummoxed. Any suggestions what might have happened? What should I do now? I'm thinking redrill, ream and install a larger pin?

Paul in Franklin.
 

Latinrascalrg1

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Just a s*** in the dark here cause im not familiar with the setupnyou are working on so please bare with me if im way off target with this Response.......

You stated this was the crank handle for the belt tensioner, correct? Have you tried lining things up with no tension on the belt, or the opposite with tensionon the belt? Maybe adding or removing (pending what you've already tried) tension on the parts associated with the crank will allow the holes to line back up for you, Maybe!
 

dlane

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#3
SB hand drilled taper pin holes back then, so any assembly with taper pins must stay together
 

cadsculptor

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LatinRascal, Since the shaft goes through a bushing of sorts, then through the crank, everything is a pretty good sliding fit and side loads don't seem to change the relationship between the hole in the shaft and the hole in the crank.

Dlane, That's what I thought - the pins are close to but never quite through the center of the shaft. That's what makes this so puzzling. Maybe the crank is not original and I only thought it was pinned? Hope my memeory isn't THAT bad!

Anyway, I see a couple options - redrill the hole for a larger pin or tap the hole in the shaft and hold the crank with a screw. Any opinions?
~Paul
 

Richard King 2

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I can be done a couple of ways. Here is how I have had the most success. Remove the shaft from the housing, slide the shaft and handle back together and drill and ream the handle and shaft in a Bridgeport or drill press and after you are done assemble it. for safety You can drill and tap a set screw into the handle so the handle and shaft are steady and won't move when you drill and ream it. See below how you can fill the shaft prior so you don't weaken the shaft by drilling multiple holes. You can buy a taper pin that is longer and cut it to length after you drill and ream the same size reamer. Using the next size up pin my leave the shaft to weak. But using the same size and ream it a bit bigger won't be an issue.

If the shaft is narrow or a small diameter you may want remove the handle from the handle and buy some Loctite Red thread lock and squirt that on anew pin the same size and slide and tap it in the original hole to fill it up. Then cut off the ends and file the ends to the diameter of the shaft. I would do this before using the above process.

The other ways you could do and if you are real steady you could drill it with a hand drill with it assembled. I have seen where an unsteady hand will drill the hole cockeyed and miss the bottom handle hole and it looks like heck with 2 holes next to each other.

I would suggest if you drill it by hand, drill from the top bigger original hole 1/2 way though and then turn the shaft 180 degrees from the bottom the small size drill 1/2 way up then ream the hole. So if there is a goof up it will be in the shaft and not as noticeable. Rich
PS: Bummer it happened, but I always say to do a dry run before doing anything and have a procedure set before drilling, gluing, welding, etc. Especially now that I am getting forgetful in my twilight years. :)
 
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