Re: [CAD_CAM_EDM_DRO] Stepper motors move wrong direction.

On Tue, 2005-11-29 at 18:21 +0000, Crs Hawk wrote:

> Help,
>
> I have a purchased a CNC router, but when I tried using it with a CNC
> application all the stepper motors turn the wrong direction.
> When I tell the drill to move up, it moves down. When I tell it down,
> it moves up.
>
> I was going to try changing the polarity on the stepper motors and see
> if they turned the other way, but wanted to find out first if any one
> had run into the same problem before?
>
> Thanks for any help in advance,
>
> CrsHawk

First, just to be sure that it's really backwards:
assuming that you're standing in "front" of the machine, and you start
at location X,Y,Z = 0,0,0

when you command "positive" X moves, the table should move left, or if
it's a gantry, the gantry should move to the right.

when you command "positive" Y moves, the table should move toward you,
or if it's a gantry, the gantry should move away from you.

when you command "positive" Z moves, the spindle should move up, so G1Z1
should move up

If you decide that one or more axes are actually reversed, you should be
able to change any one of the following to fix it:
1) the control software may have a "reverse" option for each axis.
2) the control software may allow you to use negative scales to reverse
direction
3) if you can select where the direction bit is connected, that may have
an "invert" option
4) depending on how it's wired, you can swap the polarity of one phase
on the stepper motor
5) you can swap phase A and B on the stepper motor - be careful to
maintain the same polarity when you do.

Remember to change only one of those things for each axis (actually, any
odd number of changes will reverse an axis ;) )

- Steve