Leblond chasing dial

Hi All,
I have a very nice Leblond 17" Heavyduty. At some point during it's long
life a home made chasing dial was installed. It appears to work correctly
but it lacks numbering. It has 8 marks filed into the face. 4 marks are
longer and I've always assumed these are my numbered marks. I'd like to
stamp some numbers on the dial, after a while all the marks start looking
the same. How can I verify the longer marks are my numbered marks? Does it
matter which one I call number one? I assume for half and quarter threads
the position of number 1 may be critical.
I've posted a photo of the dial here:
formatting link

Thanks in advance,
Randy
Reply to
Randy Smith
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I'm not familiar with that particular lathe but it is logical to assume that the long marks differentiate from the short ones and no numbers should be needed. It is easy to test by putting a light scribe line on some scrap, mark the index with chalk and test the other points to see what tracks in the original scribe line. Some threads will index on all the points, others only on alternate points. Bugs
Reply to
Bugs
It's usually a little more involved than that, particularly when you get down to fractional threads. For example, if one is chasing, say 11-1/2 th'ds/inch, it may require that the same number be used each time, whereas if an odd number of threads is being chased, maybe all of the same type line (all long, or all short) can be used-----or an even number, where all of the lines can be used. Without a manual to define how the particular machine works, it might be necessary to chase a few threads and determine what is required. A single scratch pass is sufficient enough to see if the tool tracks in the same place each time------no need to chase the full thread. Make notes, don't trust to memory, not if you head works like mine does these days. :-)
Harold
Reply to
Harold and Susan Vordos
The plate on the lathe states: For all even threads close half nut at any line on dial. For all odd threads close half nut at any numbered line. For half threads close half nut at any half revolution. For quarter threads close half nut at any whole revolution.
I have odd and even threads figured out. The half and quarter threads have me confused because I can't figure out which long line is whole or half (1 or 3). I'll try some scratch passes tonight.
Randy
Reply to
Randy Smith
snip----
If that be the case, it doesn't really matter, Randy. Just start with what you think is the long lines, and mark them 1,2,3,4, @ 90 degree intervals.
That should leave you with smaller lines that are offset 45 degrees from the other set, each line 90 degrees apart from one another in that set.
Once you have the numbered lines, the rest is as the chart says. Fact is, it doesn't matter which line is which, for all it does is coordinate the lead screw with the position of the spindle. The way I'm seeing it right now, once you start, regardless of where, or which line, as long as you repeat the same sequence, it works as intended. Does that make sense? Let us know if I'm wrong.
Good luck!
Harold
Reply to
Harold and Susan Vordos
snip
Just a thought from a total non-Lathe operator - but one who has been bitten before by grabbing the die stamps or electric pencil and making permanent marks on things too fast...
(It's a lot easier to take a 'bad-out-of-box' tool back if you test run it before engraving your name and DL number all over it - they start wondering if it was really that new... And the mfgr. can fix it and sell it as a refurb instead of scrapping it.)
Mark the dial with a Sharpie, or a labelmaker, or stickers, or tape and a ballpoint pen - anything semi-temporary that you can peel off or erase if it turns out later that you are wrong. Confirm that your educated guesses are right, take as long as necessary.
THEN you can get out the die stamps and ball-peen and make your permanent marks with confidence.
And triple check you're holding each stamp with the right side up, and straight, and in line with the rest, /before/ you tap it with the hammer... (I hate when that happens.)
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Reply to
Bruce L. Bergman
Chuckle!
All very good advice!
Harold
Reply to
Harold and Susan Vordos
Thanks all for your help. I marked the dial with a sharpy. I figured I'd cut a few more half and quarter threads before I stamp the thing ;)
Thanks,
Randy
Reply to
Randy Smith
If you are questioning whether there is anything critical about which of the marks you number, there isn't. When you think about it, that's the way it has to be - since any relationship of marks to leadscrew would change whenever you disconnect the dial from the leadscrew. So, mark the lines as you wish.
John Martin
Reply to
John Martin
True, as I alluded in my previous post. The only caution in this case would be to make sure the right sequence of lines gets marked, regardless of which sets, and that the stamps are well aligned. Given my luck, it would end up marked 1,2,3 @ 90 degree intervals, then to insure that Murphy's law was alive and well, I'd end up with my number 4 mark @ 315 degrees! It is a lot easier to use the Sharpie to insure the proper location.
Harold
Reply to
Harold and Susan Vordos

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