Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: kabbarnes on July 13, 2019, 10:53:29 AM

Title: Touch Plate Problem
Post by: kabbarnes on July 13, 2019, 10:53:29 AM: I finally got all Homing and Limit switches wired and they work beautifully but now the problem is I can't get my touch off plate to work anymore. It seems that all my "Pins" are used on my breakout board. Is there a way to work around this problem?
By the way I'd like to thank all you guys that help us with our problems. You put a lot of time and effort into helping and sometimes with
out even getting a thank you (I'm guilty of that). I see on most of the problems that is presented on this forum, hundreds of people read the
problems and your answers to them. Believe me when I say "You guys are Greatly Appreciated" There are a lot of newbies like me that are
getting into CNC's with out having a Background in CNC'n or any type of knowledge about them and it is daunting and confusing.
You guys that help are Bright Stars in the Night.
Thank You
Title: Re: Touch Plate Problem
Post by: TPS on July 13, 2019, 11:46:49 AM: you can wire your Limit Switches in series so that you get one pin free.

have a look here:

https://www.machsupport.com/wp-content/uploads/2013/02/Mach3Mill_1.84.pdf

chapter 4.6
Title: Re: Touch Plate Problem
Post by: kabbarnes on July 13, 2019, 12:04:20 PM: This is the problems with newbies, we never give all the information in our questions.
The limit switches and home switches our these "uxcell 4mm Inductive Proximity Sensor Switch Detector NPN NC DC 5-30V 200mA 3-Wire SN04-N2" . They act as limit and home switches and no matter how I try I can't wire them in series. (I think they can't; Ha)
Title: Re: Touch Plate Problem
Post by: MN300 on July 13, 2019, 02:16:26 PM: Mechanical limits switches are normally used as normally closed. This also allows them to be wired in series. If your prox sensors are normally open you can wire them in parallel. The input to the breakout board will be active low.
Title: Re: Touch Plate Problem
Post by: TPS on July 14, 2019, 04:18:10 AM: Quote from: kabbarnes on July 13, 2019, 12:04:20 PM
"uxcell 4mm Inductive Proximity Sensor Switch Detector NPN NC DC 5-30V 200mA 3-Wire SN04-N2"
it is a normaly Close type i think, they can be wirde in series (mostly), you can try noting will be destroyed

1st Limit
Brown - power supply +
Blue - power supply -
Black - 2nd Limit Brown

2nd Limit
Brown - 1st Limit Black
Blue - power supply -
Black - Input pin
Title: Re: Touch Plate Problem
Post by: MN300 on July 14, 2019, 08:08:55 AM: I missed the NC in the prox switch part number so my suggestion for a normally open switch doesn't apply here.

The wiring suggested by TPS could work for PNP type switches, however you have NPN. In the attached drawing the top is the TPS circuit. The bottom is a similar circuit for NPN NO switches. I can't guarantee it will work for your prox switches. Among other details, I don't know how much voltage drop there is to the output.
Title: Re: Touch Plate Problem
Post by: TPS on July 14, 2019, 12:41:29 PM: thank you MN300, i missed the NPN
Title: Re: Touch Plate Problem
Post by: MN300 on July 14, 2019, 01:23:23 PM: Details, details! I intended the diagram to be for NC switches not NO as my last message reads.
The output will be 0V when no switch is active ( no metal sensed ) and 5V when any switch is active.
Title: Re: Touch Plate Problem
Post by: kabbarnes on July 20, 2019, 10:48:55 AM: Thanks to everyone of you guys. I just got back in town last night and will go out and do some work.
Thanks again