Lead Screw install on a Monarch 60

[beckerkumm]

I'm embarrassed to admit that after five years, I'm finally getting back to the Monarch 60. The lead screw attaches to the gearbox with a bearing cartridge with two bearings. I know the bearings should oppose each other and I think the end with the narrow outer shoulder should face out on each end. That way when the bearings are pressed in, the balls push against the outer shoulder and don't fall out. ( Don't ask how i know this )

The cartridge has a loose inner spacer that sits between the bearings and there is an outer specer on the gear end and an oil seal on the end with the flange that bolts to the gearbox. I would like someone to verify the bearing direction is correct and if there is any other advice. Thanks, Dave

 

[texasgeartrain]

I didn't fully take my bearing assembly apart. One, I felt like I was going to destroy something, but the other was the bearings spun nice and felt right.

During the course I did take pics, including a parts pic that I circled for reasons I can't remember . But maybe the pics will help in some way.

 

[texasgeartrain]

My thoughts at the time of those pics are in post #115 here:

Monarch Series 61 Rebuilding for Improvement

 

[beckerkumm]

I didn't take the felt lined outer spacer off either because as you said, the pins don't seem to want to be removed. Unlike yours, my gearbox doesn't need to be loosened to attach the cartridge or flange but that may also be due to my 60 not having the lead screw reverse on the apron so I'm missing that rod. I don't know if the lever on the top of the apron needs to be in the middle position but will check that out.

I can see the bearing numbers in your picture. My replacement bearings were old stock New Departure like the originals except for the cage. If the company stamped the numbers on the same side, it would mean that the narrow outer shoulder faces out. If anyone knows for sure, I appreciate the help. Dave

 

[rabler]

Hopefully you've resolved this already. I ran into the same issue that the parts diagram is not helpful in bearing orientation. My recollectiion is that the taper's face inward >=<. (M32, M35, M32). The bearing nut on the internal end of the shaft tightens the gear onto the inner of the two taper bearings to set the preload.

 

[beckerkumm]

That corresponds to the other advice I got. The leadscrew is now installed and I'm on to the feed rod and gearbox. I only get about 2 hours a week to work on the lathe this time of year so things go slowly. The feed rod had some buggering up where it couples to the bushing and hopefully it will go in Sunday. Then on to the gearbox which is clean and should be OK. Dave

 

[beckerkumm]

I have a question concerning the feed rod. There is a casting with two bushings that holds the gear and is coupled to the rod. Mine has about .125 " lateral play. I don't remember a spacer but you can see there is a worn spot on the shaft that implies something might have been between the coupling and the casting. I don't have an exact parts diagram but a Monarch diagram doesn't show any spacer although the shaft looks different. Since the lathe is a 60 with a 61 gearbox, neither book has an exact drawing. Dave

 

[rabler]

I have a question concerning the feed rod. There is a casting with two bushings that holds the gear and is coupled to the rod. Mine has about .125 " lateral play. I don't remember a spacer but you can see there is a worn spot on the shaft that implies something might have been between the coupling and the casting. I don't have an exact parts diagram but a Monarch diagram doesn't show any spacer although the shaft looks different. Since the lathe is a 60 with a 61 gearbox, neither book has an exact drawing. DaveView attachment 390652View attachment 390653View attachment 390654

Hopefully you've resolved this already. The feed rod doesn't really bear any axial force, just torque, so it shouldn't be too critical. But I don't believe Monarch would have designed something with that much play. From the position of the wear area, that might have been inside he mounting plate?

 

[texasgeartrain]

In the thread I linked above:
Monarch Series 61 Rebuilding for Improvement

Most notably post# 26 and 32. I dealt with it a bit.

Gear on feed rod stub shaft are straight teeth, so that does not thrust on its own. And the feed rod should slide nice through apron. . .However apron does push and pull a little bit as carriage is moved back and forth. Over years, this will cause some end thrust wear.

My bushing was wore by itself, for the stub shaft, so I needed to make a new one. While make a new one, I also addresses the end thrust. Basically I cleaned up the external coupling so that it was flat. Then checking coupling to the stub shaft, determined length and placement of new bushings to reduce that end thrust to about .0015"-.002".

 

[beckerkumm]

That is basically what I ended up doing. I changed the sleeve bearings and although I bought a new oil seal, the old one was still good and i liked it better so it stayed on. I measured the distance from the gear to the casting and compared it to the distance of the gear inside the gearbox when in feed mode. That distance matched so the new bronze thrust bearing went on the outside and I turned the coupling down so the fit was good when the holes matched up.

My lock for the gearbox feed is a replacement and doesn't fit quite right so that is next. It doesn't have enough clearance to tip out so I expect some grinding will be necessary.

I was also worried about the oil hole allowing dirt in the shaft but had little on hand to put in the hole so I punched a round piece of maroon scotchbrite and put it in to catch the grit but let the oil pass. Time will tell if that was a good idea.

Dave

PS, that thread on the 61 should have a sticky so it is easy for others to find. As a note, my feed rod casting had two bearings, 7/8" long and the oil hole was drilled between them. I wondered if there should be oil lines scratched into the bronze bushings so the oil could get more easily to them but didn't do it as I figured monarch wngineers were smarter than me. Now I'm wondering but at 69 I figure the next guy can deal with it.