Logan backgear shifting difficult

J

Jack C.

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I'm new to the forum & metalworking. I recently bought a Logan/wards 10" lathe and an cleaning & painting it. The backgear is very hard to shift. I did read and try Scott Logans advice about removing and reinstalling the shift rod but the gears aren't moving like they should. When I do get the gears meshed it works good. I was trying to avoid pulling the headstock off so I thought maybe you guys had some ideas. Thanks for your help.

Jack C.
 
Jack C.:
Since you had the rack out, I'm assuming that the rod is clean and lubed. Is there any chance the rod itself has some sort of bend in it?
Have you checked the mating pinion to make sure there's nothing between the teeth, jamming things up?
Maybe some spray lube on the ends where the assembly pivots might help. Not sure if you can see the ends of the bushings with everything assembled.

Hopefully, someone else can suggest something else, before you have to pull the whole thing apart.
Good luck,
TomKro
 
Hey;

Good start on reading the adjustment procedure. It does take some fiddling, and is certainly much easier when the headstock is off. You can get the thing lined up to where it goes in, but also has a LOT of gear lash. If you play with it, you can get it set with much less lash, but this also comes at the price of it being potentially more difficult to GET engaged.

You state they work well when locked in, so your problem is that it is hard to ENGAGE the back gears, yes? That can be a little tricky in my limited experience.

I might say that it would be nice to be able to verify that your shifter and back gear sleeve and end caps were clean and well lubricated. the shfiter is easy, but there's only one way to determine that with the shaft... I would want to make sure these were all clean and well lubricated. that back gear shaft is right at the bottom where all the gunk settles, and there is no way to lubricate it externally. To shift it, you are counting on being able to catch and "swing" the eccentric back gear shaft up and around into position. It would be a lot tougher if things were not free moving. It can also be helpful to spin the spindle to help catch and engage the back gears. Raising the lid and taking tension off the flat belt while rotating the spindle might help.

All of this is coming from someone who has his headstock up on a table, not from actual use. It is relatively easy to reach down in and manipulate the back gear shaft and coax it into place in that state. Still, I can do it from the top without cheating and just reaching under to push the back shaft upwards. I'm hoping to find out one of these days for real!
 
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I guess my question would be: When you have the rack out of the machine and just try to engage the backgear by reaching inside and rotating it by hand, does everything move freely? There shouldn't be any binding at all. When everything is right it should almost fall into place. I'm working on the assumption that you have the gears meshing correctly when your trying to engage them. If you decide to take the backgear shaft out to clean and lubricate it, you can make adjusting it a lot easier by milling a slot in the end of the shaft. It's nice to be able to rotate the shaft with screwdriver and then hold it in place while you tighten the locking collar on the back of the rack.

Chuck
 
Everything TomKro and Redlineman told you is correct. I've got a 10" Logan and it shifts easily, but sometimes the gears will not engage easily, due to the teeth hitting each other. If you find that your rod moves easily, and the back gear pivot shaft moves easily, then all you need to do is (as already suggested) lift the belt cover so that you can manually rotate the spindle by hand. Rotate it slowly while pulling in the back gears and it will usually slide right into place. I usually also pull the bull gear pin prior to pulling in the back gears as well.

Now, if you are finding that the back gear rod and pivot shaft are not moving easily, your best bet will be to remove the headstock so that you can clean and lube the pivots. There is no way to get at it when the headstock is on the lathe.
 
Chuck K said:
It's nice to be able to rotate the shaft with screwdriver and then hold it in place while you tighten the locking collar on the back of the rack.
Click to expand...
Hmmmm....

I'm not seeing what you are referring to here in terms of its usefulness? I assume you mean while synchronizing the shifter? I did mine only a couple of weeks ago, and my feeble brain has already dumped what I learned then. I don't want to miss out on any neat tricks! As I recall, once I had the teeth meshed, and was happy with the lash, I simply locked the collar with about 1/16" free gap from when the latch key popped into lock position.

I had to go back down to the basement last night and refresh said feeble brain on how it all worked before I posted at all. As I had recalled, the only issue for me in getting back gears engaged is whether the gear teeth are meshing. If they are it slips right in. If not, a little turn of the spindle finds a mesh point quickly. I suppose it bears mentioning that you never want to do ANYTHING with the back gears while the lathe is running. Given the sorry state my lathe was in (mine HAD no shifter, etc), I wonder how many times someone shifted it on the fly?

Then again, that is probably an obvious answer.... ONCE!
 
Since we are on the subject;

It occurs to me that the lack of any real ability to lube the back gear shaft sleeve bushings, and the difficulty in getting that shaft out for periodic maintenance, is unfortunate. I had been toying with drilling and tapping a small hole in the outer sleeve so that I could drizzle some oil in there that would find its way out to the bushings. A very short bolt would be used as the hole plug.

Opinions?
 
Redlineman said:
Hmmmm....

I'm not seeing what you are referring to here in terms of its usefulness? I assume you mean while synchronizing the shifter? I did mine only a couple of weeks ago, and my feeble brain has already dumped what I learned then. I don't want to miss out on any neat tricks! As I recall, once I had the teeth meshed, and was happy with the lash, I simply locked the collar with about 1/16" free gap from when the latch key popped into lock position.

I had to go back down to the basement last night and refresh said feeble brain on how it all worked before I posted at all. As I had recalled, the only issue for me in getting back gears engaged is whether the gear teeth are meshing. If they are it slips right in. If not, a little turn of the spindle finds a mesh point quickly. I suppose it bears mentioning that you never want to do ANYTHING with the back gears while the lathe is running. Given the sorry state my lathe was in (mine HAD no shifter, etc), I wonder how many times someone shifted it on the fly?

Then again, that is probably an obvious answer.... ONCE!
Click to expand...

I saw this posted on the Logan forum. I had mine apart at the time so I milled the slot in the end of the shaft as was suggested. I found it to be real helpful when the machine is together and your trying to tweek the gear lash. It's real simple to do when you have your headstock sitting on the bench and you can get your paws inside to rotate and hold it in position....for myself I found that to be a little more trying when the machine is assembled. I just do it now when I have one apart...it doesn't take much to do it. As far as engaging on the fly, I would think it would be kind of tough on the fingers trying to catch that knob on the bull gear to disengage it while its spinning. Of course if you just engaged the back gear without pulling the knob out, things would slow down rapidly.:))
 
Thanks to everyone for all the great tips!! I bit the bullet and pulled the headstock. Boy you guys were right, a ton of gunk under there. When I got everything cleaned up I was able to get the shifter to work easily. I'm glad I took the headstock off cause now I understand how the gears are supposed to work. Also there was no toolpost with this lathe. Any suggestions on what to look for?
Since I'm just starting out should I try to find an old style simple holder to learn on? Thanks again for the help & Happy Thanksgiving to All.

Jack C.
 
Lantern toolposts should be pretty easy to find, and pretty cheap, too. Some of the old-time purists prefer the lantern type, but I prefer the quick change tool post, similar to an Aloris. Phase II makes a nice Aloris clone, available from many sources.

There are two types of QCTP, wedge or piston. The piston type pushes outward against the tool holder, locking it against the dovetail. The wedge type is claimed to be a bit more ridged, and better for repeatability. It has one side of the dovetail that moves in a wedge fashion to lock the toolholder. You might want to search out some of the threads here about QCTP's, as quite a bit has been written about them.
 
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