Re: Step resolution question, dividing head

Hi Jon,

Wouldn't it be 4:1 ratio, 2:1 ratio, 200 steps & 360 degrees for:

4 * 2 * 200 / 360 = 4.4444 steps/degree?

You're getting 400 steps per 90 degrees, so you can also say:

400 steps / 90 degrees = 4.4444 steps/degree.

18,000 microstep resolution? Lost you there, if your stepper is 200
steps/degree, that's not microstepping.

360 degrees / 18000 steps = .02 deg/step, but I missed where you got the
18000.

EXAMPLE:

I have a rotary table with 72:1 ratio (sherline). I "half step" it with
a 200 step motor. So I have 72 * 200 * 2 / 360 = 80 steps/degree, or
.0125 deg/step.

Might be something else in your setup? Possibly the "400 total
microsteps/degree" statement is in error, it should be: "400 total
microsteps/90 degrees", that would be 1600 steps/360 deg = 4.4444.

Hope this helps a little.

Alan KM6VV

Jon Anderson wrote:

>
> I'm working on setting up my Hardinge dividing head for a 4th axis.
> I think I've figured out a ratio that gives me even steps, at least for
> full degree moves, and wanted a double check that I did this right.
> Dividing head has 4:1 ratio, so 90 degrees per full turn of the handle.
> With 18,000 microstep resolution I get 200 steps/degree and with a 2:1
> reduction between motor and dividing head, 400 total microsteps/degree,
> or .0025 deg/microstep.
> Does this look OK? I need to get the ratio settled so I can pick exact
> timing belt pulleys, and finish designing the mounting plate.
>
> Thanks,
>
> Jon