Re: How can I calculate the INPUT_SCALE value?

Howard Chan wrote:

>[snip]
>I use SANYO DENKI servo motor which has an 2000 ppr internal encoder and
>max rpm is 3000. The motor mounts a 16T pulley and connects a 36T pulley.
>http://myweb.polyu.edu.hk/~icwfchan/p2.png
>36T pulley mounts a lead screw which is 4 turns per inch
>http://myweb.polyu.edu.hk/~icwfchan/p3.jpg
>
>According to Integrator manual, my calculation is:
>INPUT_SCALE=2000 * (36/16) * (4 /25.4)=709
>but the computer displays x-axis value is not the real-distance value.
>I try and error to find the value round 1250
>
>Would you mind telling me which part is wrong?
>  
>
It sounds like you have 3600 count encoders, not 2000.  The rest of your 
math is correct as far as I can see.

Try this:
set the INPUT_SCALE to 1000
Leave the motor disconnected from the screw and put a mark on the pulley
Jog far enough to make the pulley move 1 turn (by eye at least, more 
accurately if you can)

This will tell you whether the motor is moving as far as you think it is.

If it is, you should check the table movement by measuring how far it 
moves when you turn the screw 1 (or 10) turns.