WHY I LOVE my Vintage Monarch Lathe !

This is my Antique Monarch Model 'A' metal lathe, with an ENTIRE snowblower shaft and impeller chucked up in it.  And WHY would you want to do this?  Well a bearing was loose and had been spinning on this shaft and I needed to repair it.  I opted for the process of welding the shaft up and turning it back down to the correct diameter. In part because the damage to the shaft was deep enough that I didn't feel comfortable with metal filled epoxies and it's also below freezing outside so I don't know how well the epoxy would set in the cold workshop.

I could have done this on my Chinese 7x lathe.. IF I had removed the impeller from the shaft so I could chuck just the shaft in the small bench-top lathe.  The prospect of removing this impeller from the shaft is daunting to say the least.  In addition to its most likely being 'welded' to the shaft from 40 years of rust and corrosion, It's possible that I could have bent the impeller while I was trying to remove it. And replacement parts are 'no longer available'.  Let's not make things worse than they are.

Since the Monarch can swing the entire shaft and impeller, why bother removing the impeller.  This photo above was actually taken AFTER I have finished the weld up and turn down process and also switched back to the 3 jaw lathe chuck. I was checking the shaft for straightness and also for burrs and scratches because I have to slide the brand new oil seal on to the shaft from the end that is in the chuck. Any metal burrs would make a mess of my nice NEW oil seal.

This process started when I was hearing a rumbling sound from the snowblower I did not like to hear.  I pulled the unit apart and disassembled it down to the blower or impeller bearing at the rear of the second stage housing and discovered that once I removed a fairly decent bearing that the bearing was loose and had been spinning on the shaft:

I added some circles to that photo so you can see where the wear is on the shaft.  Sorry, I forgot to take pictures up to this point and I had already started to weld the shaft to build it up before I grabbed the camera. 

In addition to the right portion of the shaft being worn because of a loose bearing, the left hand END of the shaft was also undersized because it had been filled down to get the pulley and bearing off the shaft.

At any rate, I used some low penetration stick welding rods - 1/8 inch 6013's at low current for that size, about 70 amps on my welder to build this up.

The steps I had done to get to this point where:  The complete disassembly of the auger and blower assembly. Which included pulling the gearbox off the end of the shaft.. I mounted up the 8 inch 4 jaw chuck and used a dial indicator to get this shafting running as close to zero run out as possible.  The problem was that there's NOT really allot of the original shaft diameter LEFT to use as a reference.  There is about 3/8 inch of the old shaft between the rear of the impeller and the worn section on the extreme right in the photo.  Which is difficult to get an indicator on because of the impeller in the way.  That area is also heavily corroded due to 40 years of use in the snow, etc, etc,

I also faced off the end of the shaft because ii had been mauled from previous owners attempting to get the pulley off.  Then I center drilled the shaft so I could use a dead center from the tailstock to help maintain center. I wanted to make sure that as I welded this and it was heating up, that the shaft did not warp or deflect and I hoped the dead center would help keep it straight.

It took several passes of welding the shaft up, turning it down to oversize, welding up the spots I missed, to get a decent finish on the shaft..  I also used an angle grinder in some cases to grind down the highest spots of welding to reduce how much I had to turn down with the lathe.

To protect the lathe from the welding spatter and also the grinding I slipped a scrap piece of sheet metal under the shaft and impeller and on top of the lathe bed to catch the mess.

Once I got it all welded up and turned back down, it looks like this:

I had already purchased the replacement bearing for this which is Timken 3/4 inch self aligning 'agriculture' bearing. I was checking the bearings ID, which was .752 according to my calipers, against the diameter I was turning this shaft to.  I got the shaft to about .751 so the bearing fits very well on the shaft.  I also built up the very end of the shaft, because the V-belt pulley sets all of the way at the end of the shaft.

One of the reasons the bearing was loose and spinning on the shaft is the way this is designed.  There is not enough room in between the bearing and the pulley for an eccentric locking collar that is typical on these types of bearings.

The bearing I took out of this mess was an 'ag' bearing and it did not have the locking collar in place. I can only assume the previous repair did not use Red Loctite or Loctite #660 to cement the bearing to the shaft.

I'm kind of a belt and suspenders guy when I build or repair things. I plan to use Loctite #660 to cement the bearing to this newly turned shaft.  and I also turned down the thickness of the locking collar so I can fit it in between the bearing and the pulley..

I had to cut so far into the collar to reduce the thickness that you can see the threads (circled) of the original 1/4 inch set screw.  I re-drilled the collar for 2 - 1/8 inch set screws instead.  I also turned part of the V-belt pulley hub off the back side of the pulley so the pulley can set in the correct position on the shaft with the locking collar in place.

I should be able to get at least another 20 to 25 years old of my Antique snow blower now...