Re: [CAD_CAM_EDM_DRO] Thanks - was: Things to check? is now: RUNNING~!

Weyland wrote:

>Well, these are 7.5A motors according to the paperwork, but I might
>just try and drop them down to 6A on the Geckos to see what happens.
>(resistors are cheap)
>
>

You should make sure the idle-low power mode is turned on. It reduces
motor current when not moving.

>I think this might be where I'm getting confused...
>I'm looking at the G210 guide that came with the Geckos, but only
>see the "full step", "half step", "5u step", & "10u step" jumper selections.
>
>Would the "full step" be 1X, and the "10u step" be 10X?
>

Yes, that's right. On full-step, the step pulses are multiplied by 10, then
turned into ten successive microsteps, which moves one full step (smoothly)
on the motor. In 10 ustep mode, the Gecko 210 becomes essentially a G201.
It moves only one tenth of a full step for each pulse from the computer.

>Is this resolution you speak of related to encoder feedback?
>In other words, if I get the encoders wired up and the DRO board
>in place, will this help with this resolution, or is that something different?
>
>

No, it really won't. Having an encoder with greater resolution that the
step resolution of the driver can't make it move to more discrete positions.
(It can make it hunt like crazy.) Having the encoder with LESS resolution
than the driver means there are places you can go to, but you can't discern
that you are there. Even worse.

>And why would multiplying the steps give me poor resoltion?
>

If you use a G201, or the G210 10 ustep mode, you split a step into 10
parts.
Theoretically, ignoring friction, each of these split steps is a discrete
psition the motor can be commanded to move to. Thus, your motors have
2000 step/rev, rather than the usual 200. And, the computer can command the
motor to move to any of those 2000 positions. When you use full step mode,
you only have the 200 full-step positions that can be addressed from the
computer.
Thus, 1/10th the resolution. Now, friction is a big player here, and
the motor
will not usually move at all when a 1/10th microstep is commanded, so the
true resolution won't be as good as 1/10th of a step.

>I'm confused again...
>
>
>

We're doing our best to keep you there, or so it seems. There are so many
tradeoffs in this CNC business, there are never any hard and fast rules that
say one choice is always the best.

Jon