Scale

Does the scale function only work on whole numbers, i.e 320 400 etc or will it work with a decimal place. I have got it into my head that the scale is based on one step of a stepper motor, the driver step setting and the thread pitch. In my case it is 1.8 deg stepper on half stepping in the driver with a 1.25mm thread pitch, scale comes out of wizard as 320. If I am right then 1 step = 0.003125 mm and to increase of decrease movement by 0.01mm I would need to adjust the scale by 3.2 but if it only works on whole steps then it will be 3 @ 0.009375mm or 4 @ 0.0125mm.

I realise threaded rod is not the best thread to use but its all I have the moment.

Bill

Hi

I am not certain if you are refering to the SCALE = entry in the ini file or the scale component, assume the former.

The SCALE= figure can be floating point, and should be the number of pulses required to move the axis by one unit, in this case 1mm.

If you are using threaded rod, you may need to check movement in several places, as unfortunately it is unlikely to be consistant, any more than it is accurate.

regards

Sorry should have been more specific. It is the scale in the ini file which the wizard came out with 320. Doing the math it does work out to 320 steps per 1mm travel thats why I was asking if the scale is only whole numbers as you cant get less than a step no matter how much micro steps you have you can only have one.

............... as you cant get less than a step no matter how much micro steps........

That is not actually the case, the stepper drivers move the motor to interpolated postions in between full steps.

A good reason not to have micro-stepping too high, as they are not a physical point of attraction between rotor and magnets with a corresponding rotor tooth, so at some stage you can start substituting guessed for interpolated

This gives some detail as to how it is done
www.omega.ca/prodinfo/stepper_motors.html

regards