Who Needs A Thread Chasing Dial?

Does the lathe you ordered have a metric pitch lead screw? If so I don't think a thread dial would work.

Greg

For lathes that have a metric leadscrew, the thread dial would be used for metric threading.
 
As stated further above, planeflyer, I didn't know for sure that the 1228 didn't include a thread dial. A couple of other members said it didn't, and the product sheet they sent me didn't mention it.

I called QT this afternoon, and confirmed that it does come with a thread dial.

I think I figured out what the references to the clutch meant. Since my new lathe has a lead screw clutch, I can set a stop for the carriage and run a bit right up to a shoulder, the clutch will slip and the feed will stop. Faster threading speed and no requirement for perfect timing releasing the half-nut. Right?
 
The clutch mentioned is for the spindle mostly found on large lathes. On these lathes the drive motor is always spinning when the lathe is powered on. The spindle/clucth lever is then used to spin the spindle. On smaller lathes, when you turn on/off the spindle, that is when the motor turns on/off.

These days, a power feed clutch is starting to be offered more & more on smaller asian import lathes where as it used be a feature found only on some large lathes. Like the PM1236, I don't have a power feed clutch on mine but if you buy one today it will have it. Personally I don't care for a power feed clutch, I certainly wouldn't trust them to be used as a stop for threading. It's purpose is for emergency to prevent major damage in a crash. And if not adjusted properly, they can slip under heavy turning which can get annoying.
 
i gotcha, ive seen guys remove the dial to install dro brackets before, but after thinking about the above post, it makes sense now. thank you.
 
darkzero, It is possible to do a multistart without a thread dial. Just turn your compound 180 and dial in half the pitch. thats on a double lead. i have done a bunch of double leads and i use the thread dial to "split" the thread. even on an even pitch. I cut a triple lead a couple of times and used the compound to advance the next thread. I really dont know how you could cut a triple lead any other way. If i am missing something please let me know.
 
If the thread you're cutting can be divided evenly by the pitch of the leadscrew I think you could engage the half nuts at any point. I could be wrong too......
Yes, it is true that if the thread you want to cut is a FACTOR of the lead screw thread, you can engage at any point, such as if you have a 4 thread lead screw (common on most mid size industrial lathes) you can cut 2, 4, 8, 16, 32, etc thread pitches. If you want to cut an even number of threads, any pitch, you close the half nuts on any line, numbered or not; if you want to cut an odd number of threads, you must close on either a numbered line or un numbered line, not either one. If it is a half thread, close on opposite lines on the dial, quarter threads, close on one line or number ONLY. The lines on the dial indicate inch distances of carriage travel, so if you can stop the spindle rotation quickly enough, and open the half nuts and move the carriage back even inch distances then reclose them and start the spindle for the next cut, you can get away without the dial, but having said that, in my opinion every lathe should have a thread dial, period!
 
Threading without a thread dial is no big deal on coarse or relatively short threads. Just turn the tool out and reverse it back to the start. The threading dial really shines when you have fine and/or long threads. On a 40 tpi thread that's 3 inches long you'll spend a lot of time twiddling your thumbs while the carriage backs up. My Logan had a clutch on the power feed but it didn't work while threading. Even if you do have a clutch that works for threading relying on it to stop the feed as you crash into a shoulder doesn't sound like a good idea.
 
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