You could set A axis to linear. then set the number of steps for one revolution to one inch. then a command
G01 A36 X1
should give 36 threads per inch. 

I see now that my crappy G-code does nothing but crashing the tool in absolute mode...... Would be an even more time consuming task to write the G-code in absolute mode by hand.

You could set A axis to linear. then set the number of steps for one revolution to one inch. then a command
G01 A36 X1
should give 36 threads per inch. 

I have been thinking the same. The problem is it is probably necessary to stop the spindle two times each pass as the Y changes direction.

If you are threading, Why is Y changing directions?

As to the tool crashing, can you post something showing the fixture so we can see what you are trying to avoid?

I p

If you are threading, Why is Y changing directions?

Probably meant when X changes direction.

As to the tool crashing, can you post something showing the fixture so we can see what you are trying to avoid?

Actually I haven't connected to a machine yet.
What I meant is that I had the same position in every "A" move, 60 or 360 degrees. Not any rotational movement after the first 60 or 360 degrees rotation if running in absolute mode in Mach3. After that only -Z moves. That is the crashing of the tool into the work piece

A axis in linear mode would fix that. You may have to change the rotational settings in general config also.

As I'm a noob in cnc work I think I will keep my mouth shut for a while now......

Picture is worth 1,000 words.

This is the current 4th axis mounted on the mini mill table. (I am building a new one now but it will be similar)



As to the Y axis moving, To make the following part, after turning the barrel down. the 4th axis stops, indexes and the mill head cuts the flats across the Y axis



Linear mode is an interesting idea, but I need A to be rotary axis.

First thing to say is I reckon your attitude stinks. You have had many threads over the last few weeks and in everyone of them you have complained that the info you are getting is confusing and varied and you blame everyone for giving you confusing and contradicting info. The reason for that however is, as you have said yourself, that your questions are not asking what you are really wanting, for example it took you many posts in this thread before you actually said what you wanted, if you had said that in your first question the reply you wanted to hear would have been there right away.
 You need to lighten up and realise that people here try to help one another the best they can, no one is out to get you.

Ok if you are still reading  its onto your question, I am not sure if what you are wanting would be the best way as you would need to make sure any motion had halted before you reset your machine coords for the A axis to zero, that would require a bt more complicated code in the macropump so that as soon as the DRO reached your set amount it wouldnt screw things up. It would be much simpler to either just press the Ref A button every now and then (presuming you dont have a home switch on the A) and the machine coords will be reset. You could also write a macro (rather than a macropump) and place it in the macro folder for your profile, if you named it M111.m1s, for example,  then every time you called M111 from code or MDI your macro would be executed. All you would need in that macro is
DoOemButton(25) 

or you could have

SetMachZero(3)

They would both do the same thing as far as machine coords for the A is concerned.


Now as for the linear axis, I am taking my life in my hands here again risking you complaining that I am giving you false info again. However you may be misunderstanding what has been meant and I will give you an example of my coil winder. I have the spindle of the coilwinder set as A Axis, I have it set as a linear axis, ie 1 rev of the motor equates to 1 unit in motor tuning. Mach doesnt know or care whether it is moving along a straight line or actually roatating, all it does is move it one unit when its asked to do so. If I want to do half a revolution I would comman G0A.5, 1/4 rev would be G0A.25, 100th of a Rev would be G0A.01 etc etc.
 Whether that would be of use to you I do not know but just thought I would try to clear it up.

Hood

 

Hood you are entitled to your opinion. I participate primarily in professional forums. Hobby forums tend to be more emotional and all about pals and personalities. The Mach forum is an interesting mix of both. I'm here for information, and to help others if I can, not to find a date. Personalities do not interest me in this venue.

If reply A says "green" and reply B says "No, BLUE!". That is a contradicion, in FACT. It is not me creating the contradiction, yet you seem to imply that I am somehow responsible for it, or that it is OK and how dare I question this. Well, every forum has it's "old guard" who have grown to believe that their opinion is law and they don't like to be challenged.  They are going to answer the quetion they think you SHOULD have asked, not what you actually did ask. It happens. It's a forum, it is what it is.

In any event, as I said earlier, someone has already provided the grand hint I needed to get underway. I've tried out the function and it does exactly what I want. I just need to spend the time now to dig into Mach's scripting capability. I have perused it quickly and I see in there what I need.

"Now as for the linear axis, I am taking my life in my hands here again risking you complaining that I am giving you false info again."

I normally do not find it neccessary to kill someone, being annoying is usually sufficient. No one has yet died from my whining and I do not recall saying that HOOD gave false info, quite the opposite I believe.

In any case, thank for explaining the linear thing. I already knew "what has been meant" by that and I'm sure it works well for some. It just does not interest me as I work in azimuth mostly so it would be an unnecessary conversion back and forth, and would compromise absolute positioning that I need.