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Homing
« on: September 06, 2008, 10:58:24 PM »
I am new to CNC, I am confused as to homing . I do not have homing switches on my machine. I have noticed on the set-up videos there are min. and max. soft limits, how do I set these without switches. I noticed in a set up chart it showss 100.00 max and -100. min. but don't I need to use my table dimensions .Also how do I set the z axis, do I set the min. at the top. Thanks ,Mark

Offline Hood

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Re: Homing
« Reply #1 on: September 07, 2008, 04:36:22 AM »
OK if you dont have limits or home switches you can set up soft limits as follows.
 Go to Homing and Limits page from the Config menu and make sure you have Auto Zero chosen for each axis.
 Then jog so tool is lower left corner of your table and in the fully up (Z) Now press the RefAll button. If you look at machine coords you should now see all axis at zero. Next go to Homing and Limits again and enter Zero for X min Y min and Z Max. For X Max, Y Max and Z Min you enter your travel for each axis remembering the Z is a negative number. Also set up a slow zone, how much you need to set  is machine dependant as the decelleration time is what determines whether the zone is large enough to slow from a full rapid or indeed is too large so that the axis slows down to a crawl too far away from the end of the axis.
Once thats done you need to enable soft limits and you should be good to go.
 Remember every time you start Mach you will need to jog to the lower left fully up position and press the Ref All button.
It is fairly easy to fit limits switches so it may be best to do so, remember to use shielded wire if you decide to add some.

Hood
Re: Homing
« Reply #2 on: September 07, 2008, 10:01:44 AM »
Thank you very much, I will give it a shot today
Re: Homing
« Reply #3 on: September 07, 2008, 03:51:13 PM »
OK, this is probably the dumbest question ever,  I am almost ashamed to ask, but I am new, ready to home my machince, I know I jog to the lower left corner. My question is is the lower part of machine opposite end of motors or are the motors considered the bottom of machine.

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Re: Homing
« Reply #4 on: September 07, 2008, 05:27:08 PM »
OK what kind of machine are we talking here? I was presuming a mill or similar. When I say lower left corner I am meaning your tool will be in the lower left corner of the table, think of a graph, the origin is lower left, same idea. Another way to explain would be table moved as far right as it can go and as far away from you as it can go.
Hood

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Re: Homing
« Reply #5 on: September 07, 2008, 05:34:04 PM »
Maybe this pic of my Bridgeport will help, the X0 Y0 Z0 position is where all of the lines start.
Hood
Re: Homing
« Reply #6 on: September 07, 2008, 06:07:06 PM »
I got it , thanks again.

Offline RMD

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Re: Homing
« Reply #7 on: September 07, 2008, 06:22:32 PM »
Hood

I am kind of new about 1-1/2 years, I am wondering why your homing is in lower left? I have been using upper right and do not have any problems.

I got my X-3 from Syil America and all my limits have me homing to the X left, Y out and Z up ( X all the way to the left and Y all the out, away from the main column ).

If I change the limit switches will it make the mill run any better or since I know how to setup now like it is just leave it alone.

RMD
In STORMY Florida
RMD

Offline Hood

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Re: Homing
« Reply #8 on: September 08, 2008, 03:04:03 AM »
RMD
 It all depends how you work and also how your machine is set up. Normally if a machine is homed other than in my pic above then you will have a Home Off value set for that axis in Homing and limits. What that does is tell Mach that at your home position it is a certain distance away from machine zero and the DROs will be set accordingly.
 If you dont have a Home Off distance set then Mach will set the machine zero as that top right corner of your table and all machinng will be in a negative relation to your machine coordinates. Does this matter? Well I think probably not, just depends how you envisage things I suppose, for me X0 Y0 is best at the lower left corner and I think it is also a standard in Industry. However saying that a lot of Industrial machines home with the Y axis closest to the operator, this allows easy loading of work to the table but again I think in most cases a Home Off distance is set in them so that the machine knows where the actual zero position should be.
Hood