Sounds like an interesting machine, what model is it? What were the original rapids on it?

Hood

The machine is a mazak v5 micro center.(hardly micro at 9600 lbs), as far as original rapids I have no idea.It came from a university with low hours ,1300 ,and after the shipping company had there way, no control.I had originally tried to fit a Fagor
8055 but dumped that once I got on to this Mach thing.Believe me the support for fagor is not even on the same planet as Mach.
The machine looked like crap with a layer of crud composed of old cosmoline and dust ,it took weeks to clean up.The
paint underneath was great as are all the slide ways.The original spindle speed was 6k but I replaced the original
dc motor with an ac /vfd.Now it runns at about 8k.smooth as silk.The tool changer has 24 pockets and uses 5 proximity sensors to read the binary code on the face of the tool drum.I used the servo drives from Viper and the original motors .
This project started out as a trip to hell but I found that it turned into something more than cnc capabilities for my shop.

Just done a google to see what it looks like and seems to be a nice sturdy machine
 From what I have found the rapids seem to have been 12m/min for X and Y and 10m/min for Z so your 400IPM is not far off.

Hood

Is there an option to choose whether full form screwcutting tips are used ?
 If a sharp pointed tip is used the thread must be cut deeper than necessary just to get the required width. This is a problem cutting threads on thin wall tubes that engineers have designed to be strong enough with a proper thread form.
 Is there a way to tell mach 3 to create the bottom radius and extra width to compensate for the lack of tip radius on the tool.
The only other options I can see are to either grind the point off the carbide tip or buy new tool holders and a packet of tips for each pitch I might want to cut.
Thanks,
Glen.

You choose the finish X dimension and that controls the thread depth.

Hood

That's what I usually do but I have to cut very deep to get the required width. It weakens the tube having a sharp point at the bottom of the thread and being much deeper than should be necessary.
Glen.

So you need to use the correct profile tool.
Hood

Ok Thanks.
 I just thought there might be an option for Mach3 to generate the thread form with a sharp point tool based on the pitch.

Thanks,
Glen.

You could maybe mess around with an offset as you would when doing a multistart thread but just make the offset much smaller. For example run the thread with a start Z of 6mm then run again with a start Z of 5.9mm.

Would be much easier just using the proper insert though
Hood

You're right, it would be easier using the right insert in the long term.
Thanks for your help. ( nearly 14,000 posts - wow )