Re: [CAD_CAM_EDM_DRO] encoder count

Hi Fogassa,

> Is it really necesary to have 10 more encoder counts than the
> required resolution?

I've read that 10X is recommended, you can probalby get
away with alittle less. Just consider that you must have 'oversampling'
in order to reach your desired resolution.

Example:
Lets pretend you only want 1 mm resolution (0.040")
If you had an encoder with 1 mm res (combined with your
mechanical parts ofcourse).
Say you wanted it to be in position 50.0 mm
it could just as well be anywhere from 49.1 to 50.9 which
adds up to almost 2 mm (0.080") resolution instead !

> and as most encoders can take a max of 100k p/sec. than there is a
> max speed at the motor right? what is the formula to find out what is
> the max speed at the motor based, on the max p/sec. from the encoder?

The rate is for each channel. You can decode its two channels
(4 transitions) to get 4x the resolution with the same pulsrate.

N = Motor rpm
X = Enc. pulses in pulses/sec

N/60=X
change around a bit and you get:
N=X/60
N=100 000/60
N=1667 rpm

It doesn't matter how you decode it, the max rpm speed is the same.
You get best res. if you decode it on all transitions tho (4x)

> Thank's
> Fogassa.

np.