G93 Inverse Time Mode

I'm trying to write a Python script to add G93 to a XZA machine. I'm not having a lot of luck figuring it out. I assume I need to use trig to calculate the distance moved and I think I have that correct but I keep getting following errors from what I assume is too fast of a F word. Anyone have any ideas on the proper way to calculate the F word for inverse time mode?

Thanks
JT

That doesn't make sense, the feed rate should just be throttled if an axis can't keep up (unless this is a complex kins)

I have never used G93, so I am not really qualified to comment, but that has never stopped me in the past.

As I understand it you need to calculate how long the segment should take, in minutes, based on path-length / speed.
Then the F-word is the inverse of that time.

Actually, you can miss a step, the F-word just needs to be (speed units/min) / (length in machine units).

I note that the docs state than an F-word is needed on every motion line.

It's just a simple Axis sim with the A axis added and Y removed. It seems like only the really short segments are the problem.

JT

ArcEye wrote:

F(code) = 1(minute) / (time = 3D distance/velocity)

Yes, but 1 / (x / y) is the same as y / x

So, there is no point doing 1 / ( distance / speed ), you can just calculate ( speed / distance ).