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Author Topic: X Axis Mill vs Gantry  (Read 4206 times)

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Offline Jubei

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X Axis Mill vs Gantry
« on: April 20, 2010, 08:10:27 PM »
Hi All!

This is my first post after tons of (rtfm) :)  At any rate, I've got everything up and running, however, I seem to have a problem with how my X axis code is being interpreted.  I suspect that for a Gantry style router, the code is correct in that the spindle moves in the direction to the right for increases in X values. In a mill style, this is obviously not the case.

As the table is moves to the left, my values for X should be increasing but it doesn't.
Is there a way to fix this that I might have missed?

Thanks for the help!
Re: X Axis Mill vs Gantry
« Reply #1 on: April 20, 2010, 11:40:05 PM »
You can reverse the axis direction by changing the X direction pin "active low" state

Offline Hood

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Re: X Axis Mill vs Gantry
« Reply #2 on: April 21, 2010, 03:31:47 AM »
 Changing the active state as elpablito has said will do this but some drives are picky about that setting so best to do it via the reverse option in Homing and Limits page.
Hood

Offline Jubei

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Re: X Axis Mill vs Gantry
« Reply #3 on: April 21, 2010, 11:02:11 AM »
I understand. Homing is working properly. It homes in the direction of the home switches.

For instance, my gcode says X32.0. Instead of the spindle moving to the right as in a gantry (which would be correct), the mill table moves to the right which on a vertical mill would really be X-32.0. I will try switching the x direction "active low" pin.

Offline Hood

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Re: X Axis Mill vs Gantry
« Reply #4 on: April 21, 2010, 11:18:57 AM »
The Reverse option on the Homing and Limits page  is for changing axis direction and is the one you should use.
As said above changing the active state of the Dir pin may upset your drives. You should look up your drive literature to see what state they should be for Step/Dir.

Hood

Offline Jubei

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Re: X Axis Mill vs Gantry
« Reply #5 on: April 21, 2010, 11:37:19 AM »
The Reverse option on the Homing and Limits page  is for changing axis direction and is the one you should use.
As said above changing the active state of the Dir pin may upset your drives. You should look up your drive literature to see what state they should be for Step/Dir.

Hood

Thanks so much Hood!

I will do this instead. I guess I misunderstood what you were initially saying.

Offline Jubei

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Re: X Axis Mill vs Gantry
« Reply #6 on: April 21, 2010, 12:15:22 PM »
I tried the reverse option and it does reverse the direction, but does so for the homing switches as well.  Right now, it homes in the bottom left corner when facing the machine. So the reverse causes it to home on the opposite side and misses the home switch altogether.

Doesn't really fix the issue per se.  Would it be easier, or should I say do most people use a negative X movement for vertical mills?
Re: X Axis Mill vs Gantry
« Reply #7 on: April 21, 2010, 03:36:10 PM »
Maybe you can combine what Hood suggested with the "Home Negative" checkbox to invert your homing direction

Offline Jubei

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Re: X Axis Mill vs Gantry
« Reply #8 on: April 21, 2010, 03:41:46 PM »
Thanks elpablito! Right now I am testing. I am doing a run with the x code converted to -x. that seems to be working so far. Adjusting the homing messes up the homing directions.

Offline Hood

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Re: X Axis Mill vs Gantry
« Reply #9 on: April 21, 2010, 04:17:48 PM »
Yes, change the Home Negative setting to suit :)
Hood