Need a little help

[Blind Pilot]

Have a 10" 54" Atlas lathe, changed the lead screw support bearing, feed split nut and the gear on thread dial.
Everything works but when i engage the the feed screw the thread dial stops working, can see lead screw lift up a small amount when and thread dial stops working.
Any one have this problem ?
Blind Pilot

 

[Wierd Harold]

When the half nuts are engaged and the carriage is moving, the gear on the thread dial moves along the lead screw instead of being turned by the lead screw.
It didn't seem right the first time I saw it either. You just have to look close and see what all the bits are doing.

HWF

 

[wa5cab]

Blind Pilot,

As HWF said, when you engage the half nuts (machine running and tumbler gears engaged), the threading dial SHOULD stop turning,

However, if the lead screw lifts when you engage the half nuts, the lead screw support bearing at the tailstock end is too low and you are having to bend the lead screw to engage the half nuts. Move the tailstock to the right hand end of the bed. Loosen the screws holding the bearing and lift it up a little. Move the tailstock to the extreme right hand end of the bed and engage the half nuts. You may have to rock the carriage a little with the hand wheel to get them to engage. Pull up and down on the bearing and if there is any noticable play, center it between up and down limits and tighten the screws. Move the carriage to the point where the half nuts are half way between the bearing and where the lead screw disappears into the support at the headstock end. Stand so that you are looking straight down on the lead screw and engage and disengage the half nuts. If the lead screw moves out when you engage, you need to shim the bearing out one half of the movement distance.

Robert D.

 

[Blind Pilot]

Thank you HWF and Robert D
Blind Pilot everything working now.