Thread: Chasing Dial

Can you get a manual for the lathe in question?

Jordan

dave I believe the extra gears are for metric thread's.

If you are doing imperial print this out and stick it on the wall behind your lathe,

Hi Dave,
Do you have a chart like this somewhere?

The T number is the number of teeth on the bottom of the thread chaser.
Scale is the pick ups you can use for for that pitch.
/ means it doesnt matter when you engage the half nuts.

This is the chart off my lathe, yours maybe different.

Stuart

p.s. this only appies to metric leadscrews. imp leadscrews dont need the extra gears

thanks guys! that makes sense,

one set of gears is for metric and the other imperial.

yes we do have charts like that on our lathes

thanks

If the lathe has an imperial lead screw you don't need to touch the chasing dial but. if it's a metric lead screw you need to change the gears on the chasing dial depending on the pitch of the thread.

Originally Posted by fittermachinist

one set of gears is for metric and the other imperial.

No
If its a metric leadscrew you have gears that you can change(on the thread chaser) for picking up different metric pintches. You cant use the thread chaser for pick up of imperial pitches

If its a imp leadscrew you dont need extra gears(on the thread chaser) for pick up of imperial pitches. You can't use the thread chaser for pick of metric pitches.

Stuart

Dear Dave. Are you referring to the dial that you engauge when cutting a thread. This applies to Imperial threads. There are usually about 8 positions where you can drop in on the dial. When you have every thing organized and are about to start Usually there are numbers on the dial Take a ten thou cut and make the first thread on the job. at this stage measure the TPI to see if you have it right. Then move the tool just clear of the job and engage the half nuts if the point of the tool line up you can drop in on that position. Repeat this until you go right around the dial. This will tell you where you can drop in.
Metric threads that I have come up against usually have to have a reverse on the machin and you can not disengage the half nuts probably becaus they have Imperial lead screws. If it is an Imperial lead-screw Count the TPI and if the thread you are cutting is dividable by the leadscrew TPI then you should be able to drop in anywhere. But check with the above method. Yours 4-6--4