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KEJR
06-07-2010, 09:14 PM
Hello,

I have an old logan 210 lathe that I got from a friend. It was not used in many many years and I have now mostly oiled and cleaned up just about everything to decent order.

The carriage hand wheel tends to stick slightly when using it, such that you try to take a few thousandths off and it'll jump and take 5-10 unless you are really careful. I suspect there is some junk in one of the carriage wheels but I've lubed everything short of taking off the apron and taking off all of the parts to clean and lube them. I've loosened the carriage screws, so its not binding due to lathe wear or anything like that. I've squirted some spindle oil in the little port on the apron casting on top of the carriage wheel.

Is there somewhere I should try to apply lube, or should i break down and take the apron off and get at everything?

Thanks, Ken

lynnl
06-07-2010, 09:28 PM
Is it sticking at the same spot, with respect to handle position each rotation, or the same position of the carriage relative to the ways?

Have you checked to see if the hub of the handwheel is binding or rubbing against the boss for the shaft? Maybe a burr on the hub, or boss, or something like that? That'd be something I'd look at.

I'm not really familiar with Logans. I'm assuming the carriage advance is by rack and gear.

KEJR
06-07-2010, 09:56 PM
The sticking is not really a spot on the handwheel rotation or related to a position on the ways. It feels more like the lube on some bushing has dried out and needs to be oiled up.

I don't see any burrs or anything. The logan is a small lathe similar to a southbend 9". It is a rack based design.

I might have to take it apart, but I'd rather not since every time I do that it seems to take me an hour or two as I delve deeper into disassembly!

Thanks.

Black_Moons
06-07-2010, 10:00 PM
Way oil is explicitly designed to reduce static friction and ahear to ways. Idealy you want to coat all involves surfaces with it, the ways, the handle axles, the gears/racks/acme threaded rods, etc. Basicly just oil everything, but with way oil, it does make a diffrence. Idealy after cleaning it first :)

The Artful Bodger
06-07-2010, 10:20 PM
It might be useful to carefully clean the rack as gunge can get packed in there really hard by the passing of the carriage pinion. You will need something that can really dig in if necessary, maybe not your problem but it is easy to eliminate it.

J Tiers
06-07-2010, 10:48 PM
If your handwheel is a little loose, it can apparently cock and jam slightly.

I have a 200 series bench lathe and it does what you seem to be describing.

The symptom is that advancing the carriage gets harder, as if the tool were dulling. But releasing pressure, backing up and re-entering the cut shows that it cuts well, and indeed goes right through the spot that jammed before. I have not investigated much, but it is on the list... its a nuisance. So far I have put it down to the looseness theory, could be wrong, of course.

Since it is not at the same spot , I doubt the 'crud" theory. Especially since I have put a "crud shield"on the carriage.

Which apron /carriage do you have? The 9.25" long one, or the 10" long one?

wooleybooger
06-08-2010, 12:25 AM
i would bet that you have crud packed into the gears. my rockwell (that sat unused for several years) would do that in manual or power crossfeed. worked fine up to that point then you had to force it past that bind-up point. i thought i had a bent crossfeed screw but after taking the apron apart found swarf,dirt,and dried oil packed between 2 teeth on 1 gear. a little pecking and wire brushing and VOILA good as new. about an hour and a half start to finish.

darryl
06-08-2010, 01:35 AM
There you go. Spend the couple hours to take it apart and clean out all the crud. While it's apart, you'll get to see where all the wear is and what you'll have to work on to bring it back to being good. It will be time well spent. Most likely you'll have to repair or replace something, but then the machine will be improved. Why not-

atty
06-08-2010, 02:33 AM
My old Logan 912 sat in a garage for 7 years with the expected amount of dust that accumulated in all those years. I didn't give a thought to taking off the carriage and doing a complete disassembly and cleaning. It will be well worth it.......plus it's your initiation.

For what it's worth, I had the same symptoms, even after cleaning, and it turned out to be the carriage lock bolt. It was just slightly snugged enough to cause the binding.

Welcome to the Logan club.

Al Messer
06-08-2010, 04:36 PM
"The carriage hand wheel tends to stick slightly when using it, such that you try to take a few thousandths off and it'll jump and take 5-10 unless you are really careful."


I'm confused. Are you using the carriage handwheel to make controlled cuts? I was taught in class to use it to set the approximate location of the tool post, then lock the carriage and use the compound feed screw to do the actual cutting, or am I totally lost at sea as to the question?

KEJR
06-08-2010, 08:25 PM
I think I'll try all of your suggestions, including taking off the apron and cleaning the gears and rack all out. I just didn't know if there was something quick, or if a full disassembly/cleaning was warranted for this type of problem. Maybe I'll make it a family project, my 5 year old loves wrenching and cleaning. Thanks!

J Tiers
06-09-2010, 12:17 AM
i would bet that you have crud packed into the gears. my rockwell (that sat unused for several years) would do that in manual or power crossfeed. worked fine up to that point then you had to force it past that bind-up point.

I guess you missed the part about the problem NOT being at a specific point........ :rolleyes:

The OP said that in a reply, and I can confirm that mine does it as well, ALSO NOT at a particular point.

I happen to KNOW that the gears on mine are NOT packed full of oily swarf..... can't swear to it on his, but it sounds just like what mine does.

darryl
06-09-2010, 02:17 AM
I don't know that lathe, but it seems viable that the carriage lock could be kind of catching and 'hooking up' as it were. It wouldn't have to be in fixed spots- it could decide to stick to the bottom of the way in various and random spots. A good cleaning would eliminate much of the possible random behavior of the mechanisms.

If a cause is found that's not related to swarf, etc, I'd like to hear of it. I can certainly see where a 'control shaft' running in worn bushings might skew and jam in the same random way. If a specific cause of this problem surfaces, let us know.

daryl bane
06-09-2010, 11:36 AM
Since this hasn't been mentioned, I'll throw it out. It sorta sounds like a "stiction" issue. It might be possible that the scraping/frosting on the sliding surfaces is all but gone and you now have a almost direct metal to metal contact. Sorta like wringing gage blocks together. Oil is not able to form a complete film between the two surfaces, and thus the stiction.

wooleybooger
06-09-2010, 10:42 PM
i did notice that ,Mr j tiers. i was just throwing out another option for the consideration of the OP. misbehaving machinery doesnt always follow a rulebook. some things are simple,some are not. luckily,mine was.

J Tiers
06-09-2010, 11:02 PM
Fair enough, wooley......

Another option, which I suspect in my case, is that the loose shaft (not REALLY loose, just a bit wiggly....) allows the teeth to be jammed too closely together, which can result in sticky action because what the watchmakers call "depthing" is wrong.

Dunno..... when it happens I am never in a position to check. ;) And I can't get it to happen when I am just working the cranks..... it seems to require feeding against cutting pressure....

So, I just deal with it, knowing that if I back out and have another run at it all will probably be well..... One day I'll take a closer look.

I have a chip shield on the left side of the carriage, so it is less likely to be a "temporary" blockage by a stray chip.....