Logan model 200 shifter rack and back gear engagement/adjustment

Sorry for my ignorance but I had no clue, I'm relatively new to lathes, and had never heard about back gears until I started cleaning up & refurbishing my Logan lathe that was given to me. I'm learning but yes some of us are still in the dark on some issues.

Dwayne
 
No Worries, Dwayne;

Like I said, I found that light switch. Darkness and light are in equal measure. The overlap between members helps us all get through!
 
I don't get in here and just really spend time looking at old post, I look at the new threads but rarely old ones, this one snuck up on me & I'm glad it did, I'm looking forward to getting my Logan working right as far as the back gears. Everything else seems to be in good working order.
 
There should be a little spring loaded latch cut into the backgear engagement rod that pops out to hold the rod in the "engaged" (fully out) position. It looks a little like a woodruff key. These latches have a habit of disappearing over the years and if you got your lathe with it already gone it could be hard to figure out how back gear engagement works.
 
Absolutely;

You rarely see a fully functioning lock key on the shifter rack. Without a manual, you might not even know about it at all, and simply be left to wonder what that slot in the handle was for? ... if you even saw it!

I did a LOT of fiddling with my shifter to get it right. I had my headstock together and apart, mostly because I could not wait to see how it all fit even though I didn't have everything that went in there ready. A few times back and forth made it easier to figure out in the end, and to get it spot on. Setting the rack with the headstock on the bench was pretty easy, but doing it bolted to the bed would be near impossible if it were not for the slot mod in the end of the back gear shaft. If you have it apart, do the mod without fail. If you are having adjustment problems, it is arguably worth the trouble to go in just for that purpose alone.

My back gears make very little more noise when working than when not engaged.
 
I'm sorry to resurrect an old thread, but I am in the process of trying to adjust the shifter on my Logan right now. I cut the slot in the end of the eccentric shaft like Redlineman recommended. My problem is that I'm not sure how to get it adjusted. If I rotate the eccentric shaft all the way to the back position and insert the rack it still seems to not quite catch the teeth correctly. When the shaft is locked out the gears aren't quite enough in position to engage. I have to pull it almost all the way out to get it where it needs to be and then there is no shaft left to attach the collar to. I hear everyone that I need to adjust it so that I get an extra tooth or two on the gear so it locks, but I can't figure out how to do that. When I insert the rack, it just engages where it is and I can't get it past the gear on the eccentric because it immediately engages it. What am I missing?

Thanks in advance.
 
I'm sorry to resurrect an old thread, but I am in the process of trying to adjust the shifter on my Logan right now. I cut the slot in the end of the eccentric shaft like Redlineman recommended. My problem is that I'm not sure how to get it adjusted. If I rotate the eccentric shaft all the way to the back position and insert the rack it still seems to not quite catch the teeth correctly. When the shaft is locked out the gears aren't quite enough in position to engage. I have to pull it almost all the way out to get it where it needs to be and then there is no shaft left to attach the collar to. I hear everyone that I need to adjust it so that I get an extra tooth or two on the gear so it locks, but I can't figure out how to do that. When I insert the rack, it just engages where it is and I can't get it past the gear on the eccentric because it immediately engages it. What am I missing?

Thanks in advance.

I had the spindle out of my old 200 to lube the main bearing and replace the tail bearing, but I didn't pull the backgear assembly (because it was working fine). So I don't actually have any informed advice to offer.

That said, I'll dive right in anyway :). The way I read your description it sounds like you might not be rotating the eccentric shaft to get the gears in full mesh with the spindle gears before you insert the rack. Or you haven't pulled the pin on the bull gear to disengage it from the cone pulley, keeping the gears from fully meshing. You might have to jiggle the spindle to get them to mesh.

When I visualize it, if the eccentric is rotated toward you to fully mesh the back gears, the first tooth on the rack couldn't move past the shifter gear on the eccentric. So the eccentric needs to be rotated back just enough allow the rack to slide in past that first (or second) tooth, then rotated back toward you to mesh the rack, shifter and back gears simultaneously. Then put the collar back on.

The real difficulty looks to be in getting hold of the eccentric shaft assembly without pulling the headstock, but you've done the slot modification, so you're golden.

Somebody needs to do a YouTube video on this. It won't be me any time soon, so here's your chance.

All the best!
 
Hey Briney,

Thanks for the advice. I got it working tonight and your advice helped a lot. I was trying to do it off the bed without the spindle installed and eyeballing where I felt the gears needed to be to engage...dumb, right? So I put it all back together and used the slot to rotate the eccentric until the back gears were fully engaged, which turned out to be off of where my eyeball point was, go figure! Once I did that and got the rack in, everything lined up and works great!

My next step is to get the belt back on the motor and adjust the variable speed belt to get it running again. I'm not looking forward to any of that, especially the variable drive system. After I get it all powered back up and running, my next step is to remove the static converter and install my VFD. It's gonna be a long road, but hopefully worth it.

I bought the machine from a guy who was just making bushings with it and really didn't know what he was doing. The lantern tool post he was using was missing parts and not even close to the center of the work. The cross slide and compound were so poorly adjusted they could be pushed back and forth by hand. Before I bought it I just did a simple cut on a scrap piece he had about six inches long and somehow the machine managed to hold very tight tolerance on that despite the poorly adjusted parts. So I decided to completely tear it down, clean it up, and put it back together. I'm glad I did, I found a gear in the quick change box with broken teeth, so I replaced it. Keeping my fingers crossed that it still cuts straight when I'm done with it!

Thanks again all!
Dave
 
Hey Briney,

Thanks for the advice. I got it working tonight and your advice helped a lot...

Excellent! So you have a 200 that's been retrofitted with a gear box, but still has the original, no clutch apron? If so, be very, very mindful when you're power feeding and near the end of travel. With no clutch, if you hit the end of travel catastrophic damage will ensue. Don't ask how I know. Be mindful even if you have a clutch, because it can probably still pop gear teeth.

I'm trying to finish up an electronic lead screw on my 200, and hoping that the stepper motor torque limit will provide some protection, but I don't think I will have the nerve to test it. I haven't been able to stall it yet, so it might still have enough torque to break something.

Have fun! Glad I was able to help a little.
 
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