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Author Topic: Home Switch Working As Limit Switches At Both Ends Question  (Read 3684 times)

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Home Switch Working As Limit Switches At Both Ends Question
« on: December 07, 2013, 11:01:51 PM »
I think I read a comment from Hood saying it is possible to have the home switchs in the middle area of the table and also set it up to work  as limit switches at both ends of the travel. Please explain how to set that arrangement up. I currently have homing switches on X Y & Z axis, and I have soft limits working for all axis. I would prefer to have limit switch protection set up instead of soft limits.

Offline Hood

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Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #1 on: December 08, 2013, 03:18:06 AM »
It depends on the type of machine you have and where the switch is fixed but if you look at the quick sketch I have just down you will see how you can do it.
Just set the same pin up as Limits as well as home.
Hood
Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #2 on: December 08, 2013, 08:55:06 AM »
Thanks for the drawing. I have optical switches. I guess I would need a second flag installed for them to work as shown.

Offline Hood

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Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #3 on: December 08, 2013, 11:13:05 AM »
Yes just an extra flag at the opposite end is all thats needed :)

Hood
Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #4 on: December 08, 2013, 01:48:58 PM »
Thank you Hood for all your help with people's questions. You are a real asset to the forum.
Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #5 on: December 09, 2013, 03:58:41 PM »
Hood,
I added a flag to the end of the X travel and it works as a limit and stops the travel. My home switch flag is not at the other end of the travel. It is about 2" from the end. Can I have the table move the aditional 2" to another flag set as a limit? Now when I try to over travel at the far end, the limit flag stops the travel as it should. When I go to the end where the home flag is, the table stops there as if it hit a limit switch. Can I make the table bypass that flag and go the 2" to the limit flag? The table homes correctly with no problems. Right now, the home flag works as homing, and also works as a limit.

Offline Hood

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Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #6 on: December 09, 2013, 04:09:47 PM »
Afraid not, to have a separate home switch you need to physically have another switch.
Hood
Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #7 on: December 09, 2013, 04:16:14 PM »
I guess I will have to move the home switch the 2" to the table travel end so I can use that area. Whoever set up my X3 mill placed the home optical switch in the wrong place I guess. Thanks for the answer.

Offline Hood

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Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #8 on: December 09, 2013, 04:22:59 PM »
You will just need to move the flag unless I am not understanding.
If however you wish to have a home switch that is not at the axis extent then you will need to add another switch to either act as a home switch or a limit switch. On a smallish machine like yours then really there is no benefit to having a separate home switch unless you can home to an encoders index pulse, that however is not likely unless you have both servos and some means of doing the homing routine to the index pulse..

Hood
Re: Home Switch Working As Limit Switches At Both Ends Question
« Reply #9 on: December 09, 2013, 04:29:45 PM »
I understand. I would need a limit switch using a different pin. I think I will have to move the flag.