Is pivoting the threading dial out of engagment important?

[737mechanic]

I notice many people pivot the threading dial away from the lead screw when not using it. I have always left mine engaged. Since it doesn't spin fast I didn't figure any significant amount of wear would occur but I want to get you guys opinion.

[spro]

I think it is one of those things where we forgot what we used to know. Sure there is some wear and mine are probably engaged. Thanks for the reminder. When there is only one bolt to swing it away, why should it climb the lead screw at every traverse of the carriage. There is a different wear against the screw while this is happening and it isn't the helical slide fit.

[10KPete]

I've never disengaged mine. Just make sure it's engaged with a few thou clearance and it won't wear enough to worry about.

Pete

[Harold_V]

The real concern is that the vast majority of time one is not using the screw for threading, yet the dial is always engaged. It turns when the carriage is traversed, not just when the screw is in operation. For that reason, if you have the least doubt about it being able to withstand constant engagement, use your lathe with the dial disengaged. In many cases, it's dead easy and fast to engage as required.

Harold

[NP317]

I leave the threading dial on my lathe disengaged, unless I need it for threading.
I see no need to use machinery unless it is actually required for an operation.

Less movement, less wear.
'Just my general approach to machines.
~RN

[Mr Ron]

I think it's pretty much common sense to keep the dial disengaged when not in use. Metal-to-metal contact means wear, something that should always be discouraged, no matter how little. Chips can get onto the screw and work it's way into the thread dial. Disengaging is no big deal.

[Gary Armitstead]

I leave mine dis-engaged unless I need to do some threading. Just an old habit.

[Kimball McGinley]

Mine stays OFF the lathe unless I need it. In its place I added a short tab that contacts a dial indicator that travels on the ways.
I use that a LOT more than I use the dial for threading. I could take a picture if anyone is interested.

[wsippola]

Can't disengage it on the 10EE. But the leadscrew only turns for threading too.

[BadDog]

What happens when you move the carriage? The dial still runs against the lead screw like a pinion on a rack. That's the reason I keep mine kicked out unless threading. I also clean and oil the lead screw in the area I'll be using before engaging either the dial or half-nuts. My lead screw is about 1.25" diameter and appears almost unused, likewise for the brass gear on the thread dial, and i want to keep it that way. Plus there is the shaft and bearing of the dial which isn't auto lubed on my lathe, so it saves wear and manual oiling there as well when not in use.

[Harold_V]

What happens when you move the carriage? The dial still runs against the lead screw like a pinion on a rack.

Yep! The only time the thread dial is not in motion is when you're actually chasing a thread, assuming you have the dial engaged. Likely not a big deal, but if one hopes to have a lathe go the distance without issues, disengaging when not in use is one way to help achieve that goal.

Wiping and oiling regularly goes a long ways towards that goal, too. I've said it before, and I'll say it again. If the oil on the ways of a machine is discolored beyond the color it was when it was applied, it is long past due to be wiped and replaced. Yeah, I realize that's not the point at hand, but after viewing, on the internet, the ways of several machines, someone needs to speak out. For some reason, some folks seem to think the way oil should be black, not caring that the black they see is the ways wearing away due to dirty oil.

In regards to the lead screw, my lathe doesn't use the screw for feeds, so it stands inactive unless called upon for threading. When it is, it is blown free of chips and crud and then oiled generously in the areas where it will be used. Like yours, the screw on my Graziano is still pristine after 49 years. Hard for me to believe it was that long ago.

Harold

[Hopefuldave]

Like Wsippola's 10EE, my Holbrook has a dial that doesn't disengage and also serves as a rough travel indicator - unless the leadscrew's driven specifically for threading it's stationary and firmly located (by Holbrook's "Patent Leadscrew Thrust" assembly), so acts as a fixed reference for the dial. It has lasted 60 years so far, without any discernible wear...

Dave H. (the other one)