Re: [CAD_CAM_EDM_DRO] A few questions: 3:1 ratio okay for accuracy? is my setup correct?

I think that you do not have the proper numbers entered even if it may be
giving the correct steps per inch. I am assuming that you do not have 25
line encoders which is what you would need to get 25 steps/rev. What we
really need to know is the line count of the encoders and what multiplier
ratio you have the G340 set for. Then with the other information we can
figure it all out.
Steps per revolution will equal 4 x the lines on the encoder. So if you have
a 250 line encoder (far more likely than 25) you will get 1000 encoder
counts which = steps with this drive after you divide by the pulse
multiplier setting. So if the pulse multiplier is set to 1 X (no
multiplication) than you have 1000 steps per rev. If it is set to 10 than
you would have 100 steps per rev (way to low, but it is an example).
You should have 0 in microstepping as the drive does not microstep.

The way you have it configured I would guess that you really have a 500 line
encoder and that the drive is set to 10 x pulse multiplication. That means
that the motor really has 2000 steps per rev and the drive is then reducing
it to 200 which equals the 100 step per rev then doubled by 2 x microstep.
Works, but not my idea of optimum. I think I would set the drives to 5 x
pulse multiplication and then use the settings of 400 steps per rev, no
microstep and keep the reduction and TPI you have. You may also want to play
with the 2 x pulse multiplier setting and then use 1000 steps per rev.

Tim
[Denver, CO]

----- Original Message -----

> A few questions: 3:1 ratio okay for accuracy? is my setup correct?
>
> 1)I am running a 3:1 ratio for my servos, will this have an effect on
> accuracy since my step increment will be .00033333333 inches and is
> not a nice even number such as .0001 or even .0005.
>
> 2)I have no idea of the "Steps per Rev" of my motor. I just played
> with different numbers until "100" gave me the motion I wanted.
>
> I also played with the "Microstepping" input as well, so I am not
> sure which number is correct or if I was just lucky.
>
> This is my setup:
> Steps per rev: 100
> TPI of screw: 5
> Microstepping: 2
> Reduction: 3
>
> Motors are Litton 420oz brush DC servos (bought from Camtronics many
> moons ago)
>
> I did spin the motor manually and counted 22 "detents"...does this
> mean anything? I'd like to be as accuate as possible with my setup
> and I am not sure if 100 SPR is okay or not, just 'cause it works,
> does not mean it's correct....
>
> I'm running Gecko 340's as well.
>
> Thanks
>
>
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