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### Author Topic: wiring diagram for limit switches  (Read 19751 times)

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#### inivator

• 102
##### wiring diagram for limit switches
« on: June 15, 2008, 04:29:54 PM »
I'm building a gantry type small router.  Is there any wiring diagrams for simple xyz limits and homing switches.

Inivator

#### Hood

• 25,856
• Carnoustie, Scotland
##### Re: wiring diagram for limit switches
« Reply #1 on: June 15, 2008, 05:35:01 PM »
Dont really need a wiring diagram, all you need are normally closed switches and run them all in series, ie have a wire from an Input pin of the parallel port(or breakout board) run this to one wire of first switch, other wire of first switch goes to one wire on second switch, other wire on second goes to third switch and so on until all your switches are connected then the last wire goes to a ground on your port (or breakout)
Doing it that way will mean you only use one pin of the parallel port for all limits and Home switches. If you prefer to have each axis seperate then you can wire all the switches on each axis in series and use one Input pin for each axis.
Hood

#### montejw

• 57
##### Re: wiring diagram for limit switches
« Reply #2 on: June 15, 2008, 09:22:58 PM »
Dont really need a wiring diagram, all you need are normally closed switches and run them all in series, ie have a wire from an Input pin of the parallel port(or breakout board) run this to one wire of first switch, other wire of first switch goes to one wire on second switch, other wire on second goes to third switch and so on until all your switches are connected then the last wire goes to a ground on your port (or breakout)
Doing it that way will mean you only use one pin of the parallel port for all limits and Home switches. If you prefer to have each axis seperate then you can wire all the switches on each axis in series and use one Input pin for each axis.
Hood

Monte

#### jimpinder

• 1,233
• Wakefield, West Yorks, UK
##### Re: wiring diagram for limit switches
« Reply #3 on: June 15, 2008, 11:04:56 PM »
You do not need any if you have a "dead" breakout board, because the LPT1 port has built in pull-up resistors.
You may need one at the "pin" end of your breakout board - depending on how it is configured - you will have to read up on it.

The idea is the pin is normally +5v. The path through the series of switches to earth holds it at 0v until one of them (and as Hood said - you can have as many as you like) opens, and cuts the 0v path. The pin should then go to +5v to give a signal to the computer.

Some breakout boards have isolators on them, and the pin out voltages are reversed i.e. where they are normally held to 5 volts (from the computer) they are at 0volts on the breakout board. If this is the case you can either use a pull up resistor to pull it up if a switch is activated - or instead of the last switch being connected to 0v, connect it to 5 volts - so that the idea of the series path is the same, but just operating in reverse - normally held at 5 volts,  when the  series is broken it drops to 0
Mach 3 can cater for both systems.
Not me driving the engine - I'm better looking.

#### inivator

• 102
##### Re: wiring diagram for limit switches
« Reply #4 on: June 16, 2008, 07:36:16 AM »
Understand the wiring now, but how is the configuration in the Mach3 software setup?

Inivator

#### Hood

• 25,856
• Carnoustie, Scotland
##### Re: wiring diagram for limit switches
« Reply #5 on: June 16, 2008, 08:08:51 AM »
If you have all limits connected in series and using one input then you just asign that input for every axis, ie if you have X+,X-,Y+,Y-,Z+Z- all connected in series and going in to pin 12 then you set them all to pin 12. Same for the Homing switches, you can actually use a limit switch as a home switch, Mach will only see it as a home switch when you have told Mach to Home, all other times it will be treated as a limit switch.

Hood

#### inivator

• 102
##### Re: wiring diagram for limit switches
« Reply #6 on: June 16, 2008, 08:20:52 AM »
Thanks...Sounds simple, very similiar to my mind...........

Inivator

#### Hood

• 25,856
• Carnoustie, Scotland
##### Re: wiring diagram for limit switches
« Reply #7 on: June 16, 2008, 11:06:15 AM »
Thanks...Sounds simple, very similiar to my mind...........

Inivator

You are in good company then

Hood

#### inivator

• 102
##### Re: wiring diagram for limit switches
« Reply #8 on: June 16, 2008, 01:05:28 PM »
Hood;

When you're ready to take a vacation, come to TEXAS, and I will show you how red-necks live.................I've been here 70 years, and have just about figured it out, whatever it is............

Inivator

#### Hood

• 25,856
• Carnoustie, Scotland
##### Re: wiring diagram for limit switches
« Reply #9 on: June 16, 2008, 03:02:20 PM »