Feeling a little restricted.

[Richard.]

I'll take pics and show you what I did
Was probably wrong mind.

 

[MattH]

Ignore all the wusses learn to use the TDI it makes cutting threads so much easier and quicker.
If you have a manual it should tell you The pitch of the leadscrew and therefore which graduations you can and can't engage at for each thread.

 

[Richard.]

While the lathe was running I engaged the feed with this bad boy which set the travel to cut (pic1)
The thread dial (pic2) remained at zero as the half nuts were always engaged but I could stop the feed with the item in pic 1. Then I wound it out
And bought it back with (pic3)
Bought it back in to cut again then reingaged with pic1

Is that a bad way.

 

[optima21]

how about making a spindle driving handle like this if the slow speed is too fast.

http://www.instructables.com/id/Lathe-Spindle-Handle-for-a-Myford-ML10/

(picked at random off the net)

or if you're feeling flush you can buy one

http://www.myford.co.uk/acatalog/How_to_Use_Spindle_Driving_Handles.html

 

[Richard.]

Pics

 

[MattH]

While the lathe was running I engaged the feed with this bad boy which set the travel to cut (pic1)
The thread dial (pic2) remained at zero as the half nuts were always engaged but I could stop the feed with the item in pic 1. Then I wound it out
And bought it back with (pic3)
Bought it back in to cut again then reingaged with pic1

Is that a bad way.

Yes, you are disengaging the leadscrew whilst the spindle is still turning. That's a big nono when threading.
You should either, leave the leadscrew engaged and stop and reverse the motor or disengage the halfnuts with the lathe still spinning and wind the carriage back with the rack and pinion and then re-engage the halfnuts at the appropriate graduation.

But it looks like you don't have a rack and pinion so my advise might be rubbish in relation to the ML10.

 

[brightspark]

how about making a spindle driving handle like this if the slow speed is too fast.

http://www.instructables.com/id/Lathe-Spindle-Handle-for-a-Myford-ML10/

(picked at random off the net)

or if you're feeling flush you can buy one

http://www.myford.co.uk/acatalog/How_to_Use_Spindle_Driving_Handles.html

i made my own fits both lathes http://www.mig-welding.co.uk/forum/threads/home-made-headstock-hand-tapping-handle.39564/

 

[Richard.]

Ok I don't understand. My thread dial even when the half nuts are not engaged keeps turning. How can I set it while the lead screw is turning it. This is why I did it the way I did. It's only when I release the dog drive I can set it.

 

[MattH]

You don't set the dial, you wait and watch it turn until it reaches the correct graduation then you engage the halfnuts.

 

[doubleboost]

You don't set the dial, you wait and watch it turn until it reaches the correct graduation then you engage the halfnuts.

The dial stops when the nuts are engaged it is easy to get muddled up

 

[Richard.]

The rack and pinion is actually the lead screw thread

 

[Richard.]

You don't set the dial, you wait and watch it turn until it reaches the correct graduation then you engage the halfnuts.

Mid flight????? On the fly???? So while it's turning I hit the lever at exactly the right time.
I got no chance.

 

[MattH]

The rack and pinion is actually the lead screw thread

Yep, that screws up most of the standard advise I have given.

 

[MattH]

Mid flight????? On the fly???? So while it's turning I hit the lever at exactly the right time.
I got no chance.

Yes, that's how a TDI works.

 

[Richard.]

Ah ok just had a go.
It's not as hard as I thought.

 

[brightspark]

Mid flight????? On the fly???? So while it's turning I hit the lever at exactly the right time.
I got no chance.

its not as bad as it seems its easy practice it without cutting sometime

 

[addjunkie]

Not sure on your machine but thread dial indicators on bigger machines can be engaged or disengaged, they are just a gear driven by the lead screw.

Another observation, when your winding the tool in and out, if the machine is tight with no back lash no big deal, but most have some back lash to be accounted for, so as i keep the half nuts engaged and reverse the machine, i actually mark the dial with a dry wipe pen. Then when cutting up agaist a shoulder, with a recess, i whip the tool out as i stop the machine. Then take it back in reverse.( thats what i meant by timing earlier). Wind the tool back in to the mark, plus the extra cut and mark again. Saves me remembering where i was on the dial.

Some say to use the top slide set at half the thread angle, for a better thread finish, but i just use the cross slide.

 

[Richard.]

Ok I can do that.
I'll leave the dog drive engaged and just engage the feed when the tdi hits the same mark every time then bring her back on the pinion.
With the tdi handle and repeat yes?

 

[MattH]

Some say to use the top slide set at half the thread angle, for a better thread finish, but i just use the cross slide.

I'm sorry but that is bad advice. "Some" don't say, it is the way it is suppose to be done unless you are using an appropriate full cutting insert tool. The reason for the compound being set to half the thread angle is so that when you advance the tool it is only cutting on the leading edge of the tool. If cutting on both sides you will get increased chatter and a poor cut.

 

[MattH]

Ok I can do that.
I'll leave the dog drive engaged and just engage the feed when the tdi hits the same mark every time then bring her back on the pinion.
With the tdi handle and repeat yes?

Yes, exactly.