just purchased a myford 7 ,have a question, when threading can I stop after a pass then wind the carriage back without disengaging the halfnut via the wheel at the end of the lead screw then take another cut ,and so on
thankyou in advance
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just purchased a myford 7 ,have a question, when threading can I stop after a pass then wind the carriage back without disengaging the halfnut via the wheel at the end of the lead screw then take another cut ,and so on
thankyou in advance
I’m pretty sure that’s an option on most lathes. Certainly hobby lathes anyway. This might help: https://youtu.be/ksCd9FfjUFQ
thankyou for that info ,now I,m clear on what I imagined ............bob
Yes, but probably no. Yes, you can quite often use the handwheel on the leadscrew to wind the carriage back, but you may find that the ratio between the spindle and leadscrew will cause lots of forces on the gear rain that could damage the gear train. The extreme case is say, cutting a thread of 0.5 TPI or courser threads - 0.1TPI or less. Cutting those kind of threads it is usual to drive the spindle from the leadscrew. Forces are better with that arrangement.
Why on earth would you want such a course thread? Answer: Multi start threads, or rifling in a barrel come to mind.
Proceed with caution! Probably better to install a motor reversing switch.
This works reasonably well on a Super 7 as long as you disengage the clutch.
I have tried to move the carriage back using the leadscrew handwheel - hard work, and it reeked of breaking something, so I found it easier to rotate the chuck by hand. I was only cutting a short thread - metric by memory. At that time I felt a motor reversing switch (for a single phase motor) would have been a good investment. Being an electrician I had no excuses - except to get the job done quickly! Did I later fit a reveresing switch...... well no, I sold the lathe. Never being able to learn from my mistakes I later purchased a three phase Super 7. Motor rotation is now a simple "flick of the lever"
Yes ypu can by using the reversing switch. This is done on an ML7 when producing a metric thread only, leave the tgread counter in place, retract the slide a little noting depth of cut also. When doing imoerial threads simply unlock the carriage leaver and rotate the handle nto the start position again.
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no real need to reverse unless you are doing metric threads and cant disengage the half nuts.
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