Threading with out a shoulder

[RJSakowski]

It looks like the Emco has a variable speed drive, in which case you can slow the spindle down as you approach the end of the thread. Since the available torque approaches zero as you decrease the spindle speed you should give very good control to stop threading at a precise point. I would still cut the groove but you should only need to make it only a thread or two wide.

On my Atlas lathe, I would purposely loosen the drive belt to reduce available torque to accomplish the same thing. It would cut the thread but if it ran into virgin territory or up to a shoulder, the belt would slip and the spindle would stall.

 

[Cr23484]

It looks like the Emco has a variable speed drive, in which case you can slow the spindle down as you approach the end of the thread. Since the available torque approaches zero as you decrease the spindle speed you should give very good control to stop threading at a precise point. I would still cut the groove but you should only need to make it only a thread or two wide.

On my Atlas lathe, I would purposely loosen the drive belt to reduce available torque to accomplish the same thing. It would cut the thread but if it ran into virgin territory or up to a shoulder, the belt would slip and the spindle would stall.

My Emco Compact 5 does not have variable speed.
It has 6 speeds that are set by changing the belt position.
Thanks
C

 

[plunger]

Im not familiar with the emco 5 but if its the same or similer to the emco compact 8 it probably goes way to fast. I made a hand crank and that solved the problem somewhat.I also have a crank on the right hand side of the leadscrew but never tried that as the hand crank works well. There is also a lever that disengages the motor from the spindle but never tried that either. Does the emco 5 have that.?

 

[Cr23484]

Im not familiar with the emco 5 but if its the same or similer to the emco compact 8 it probably goes way to fast. I made a hand crank and that solved the problem somewhat.I also have a crank on the right hand side of the leadscrew but never tried that as the hand crank works well. There is also a lever that disengages the motor from the spindle but never tried that either. Does the emco 5 have that.?

The slowest speed is 250 rpm.
There is not a lever on the Compact 5 mini lathe.
I might try a shaft that has 2 inches of room to move without any cutting.
Thanks
C

 

[Cr23484]

I think I will practice on Delrin.
C

 

[hman]

PVC pipe is also a good practice material - easy to machine, no harm if the tool digs in unexpectedly, and it's dirt cheap.

 

[Cr23484]

Thanks Hman!