DocsMachine
Titanium
- Joined
- Jan 8, 2005
- Location
- Southcentral, AK
Okay, I've got a big 16" Springfield lathe (currently still in parts) with a leadscrew reversing mechanism, so I don't think it came with a threading dial.
I'm used to threading with a dial, however, and so at least for the time being wanted to have a dial available and usable. Original Springfield parts are basically unobtainium, so I'd been keeping my eyes open for one that might fit. That is, a fairly big one.
Another PM'er recently had one, of unknown make or origin, but his pic showed it was pretty substantially sized, and the asking price was right. I picked it up and just got it in today.
Now, I expected I might have to replace the gear- I figured I was just buying a "kit" that I would have to adapt to my machine. However, the gear proved to mesh quite nicely with my leadscrew (shown here obviously not attached to the machine.)
The leadscrew is 6 TPI...
\
And the gear has 36 teeth, which is evenly divisible by 6. The dial face has 6 divisions as well...
Although badly beat and in dire need of a refacing and restamping.
I am not exactly up to speed on how thread dials work, but I was given to understand the gear needed to be evenly divisible by the leadscrew TPI pitch, and that the dial needed to be that number (IE, the number of times the gear tooth count is divisible by the leadscrew pitch.
If that's wrong, please keep in mind that's all knowledge gained in passing, with a heavy dose of assumption to boot.
So, did I luck out and get a dial I can use more or less as-is, albeit with some cleaning, or will I need to rework it, and if so, how do I do that? What gear pitch should I have, if that's the case?
Thanks.
Doc.
I'm used to threading with a dial, however, and so at least for the time being wanted to have a dial available and usable. Original Springfield parts are basically unobtainium, so I'd been keeping my eyes open for one that might fit. That is, a fairly big one.
Another PM'er recently had one, of unknown make or origin, but his pic showed it was pretty substantially sized, and the asking price was right. I picked it up and just got it in today.
Now, I expected I might have to replace the gear- I figured I was just buying a "kit" that I would have to adapt to my machine. However, the gear proved to mesh quite nicely with my leadscrew (shown here obviously not attached to the machine.)
The leadscrew is 6 TPI...
And the gear has 36 teeth, which is evenly divisible by 6. The dial face has 6 divisions as well...
Although badly beat and in dire need of a refacing and restamping.
I am not exactly up to speed on how thread dials work, but I was given to understand the gear needed to be evenly divisible by the leadscrew TPI pitch, and that the dial needed to be that number (IE, the number of times the gear tooth count is divisible by the leadscrew pitch.
If that's wrong, please keep in mind that's all knowledge gained in passing, with a heavy dose of assumption to boot.
So, did I luck out and get a dial I can use more or less as-is, albeit with some cleaning, or will I need to rework it, and if so, how do I do that? What gear pitch should I have, if that's the case?
Thanks.
Doc.