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Homing
« on: September 23, 2010, 08:32:14 PM »
When homing it goes to switch, reverses, starts to move, but wont't come all the way off the switch. How can I adjust this so it comes off the switch?
Thank you
Re: Homing
« Reply #1 on: September 24, 2010, 01:26:24 PM »
Here's a thought. If I move the motor pulley a few notches in the belt, so it will make it to the switch, will that work?
Thanks

Offline Hood

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Re: Homing
« Reply #2 on: September 24, 2010, 01:36:05 PM »
The way Mach does homing is it moves towards the switch until it is activated, the axis then reverses until the switch is deactivated and that is set as Home.
Normally with your problem I would say your switches are bouncing, this can happen with low quality switches that do not snap open and closed.
However as you have recently mentioned you are using the Ajax plugin it may or may not be the problem as I dont know how Ajax handle the homing. Try setting a debounce interval of 2000 and see if that helps, if it does then lower it until you have problems again then step up slightly. If that doesnt help then it would probably be best contacting Ajax to see how it handles the homing.
Debounce Interval can be found on the General Config page accessed from Config menu.
Hood
Re: Homing
« Reply #3 on: October 06, 2010, 05:27:58 PM »
I found out with the Ajax plugin, it is supposed to homes to the switch, and then backs off untill it sees the encoder index. I can get x to home properly, but then it just sits there, and will not home y or z. Ajax doesn't have any ideas, except to reload Mach. I'm going to try that.

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Re: Homing
« Reply #4 on: October 06, 2010, 05:38:50 PM »
Does the machine coords for X axis get updated? If not sounds like the plugin is not informing Mach.
Hood
Re: Homing
« Reply #5 on: October 06, 2010, 06:12:53 PM »
The motor homing percent of speed and acceleration profiles will also affect the homing position.  We had an X axis that would not always home to the same position, sometimes it would not change direction.  After changing the homing speed percent from 20 to 30, the problem was fixed.

JH

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Re: Homing
« Reply #6 on: October 06, 2010, 06:24:25 PM »
JH I am not sure if that will help in this case. It would be good to know exactly how the homing routine is done but I suspect it is done in a similar manner to the way I do things except rather than the drive doing it as in my case it will be the plugin/plc/controller in the Ajax case.
 Mach knows nothing of me homing my mill and lathe until it is told by my  PLC that it has homed and I suspect the Ajax will likely work in a similar manner, would be good to find out for sure though.
Hood
Re: Homing
« Reply #7 on: October 07, 2010, 01:47:02 AM »
Does the machine coords for X axis get updated? If not sounds like the plugin is not informing Mach.
Hood

The code to home all three axis is: M92 P11 Q12 R3. It does go to x, and machine coords for x does update to zero. It is suppose to then home y and then z, but it stops at x.
Thanks
Re: Homing
« Reply #8 on: October 07, 2010, 01:52:20 AM »
Hi,

I'm having the similar problem.
When homing it goes to switch but don't reverses. How can I configure so that it comes off the switch?

Thanks
My CNC Store: http://liana-tech.com
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Offline Hood

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Re: Homing
« Reply #9 on: October 07, 2010, 02:22:24 AM »
Does the machine coords for X axis get updated? If not sounds like the plugin is not informing Mach.
Hood

The code to home all three axis is: M92 P11 Q12 R3. It does go to x, and machine coords for x does update to zero. It is suppose to then home y and then z, but it stops at x.
Thanks
Can you attach the M92 macro please.
Hood