Rotary axis: steps/rad vs. steps/degree

o_lampe

Hi gents,
it looks like the rotaty axis in RRF are controlled in steps/degree. IMHO it would be much easier to use steps/rad, because 100rad = 1 turn which is a better match for 200 or 400 steps/turn steppers.
Is there a way to implement this?

THX
Olaf

dc42

@o_lampe I've never heard of "rad" being used for 1/100 of a turn. It sounds more like an abbreviation for radian, which is 1/2*pi of a turn. Perhaps you meant grad/gradian/gon ? See https://en.wikipedia.org/wiki/Gradian.

You can use a calculation to define the steps/degree. For example, if you have a 5:1 gearing between a 200 step motor and rotary axis A, and assuming x16 microstepping, you could use this:

M92 A{200 * 5 * 16 / 360.0}

You need to include a decimal point in at least one of the numbers so that the division is done using floating point maths, not integer maths.

o_lampe

@dc42 Well, I guess it's time to give back my diploma...I was totally sure there is a unit that divides a full turn into 100 fractions. But I forgot the 2*Pi thing.