View Full Version : limit switch connector options?

03-09-2010, 07:44 AM
Hi all,

I'm about to wire up my CNC router machine mk2 for limit switches (using microswitches with rollers again) and wondered what other people used for the connectors into their control panel (e.g phono, jack, etc.). Since these cables should be shielded, the connector needs to allow for this. Any thoughts?


03-09-2010, 10:18 PM
Had another look around the internet this evening. Alot of 9 pin D-sub connectors in use, but was hoping for seperate x,y,z connector ideas. Anyone use anything different?


03-09-2010, 10:47 PM
Why do the limit switch wires need to be shielded?

04-09-2010, 12:16 AM
D-Sub, 9, 15 or even 25 pin are good for when you need a high pin density, but as you say are an all or nothing solution.

Jack plugs have their place for 2 to 4 poles but I'm not a fan, after a few good twists and pulls the connectors can bend leading to intermittent contact.

Phonos can be nice, especially the locking versions

My favourite low pin count connectors have to be XLRs. Good for something like 3 Amps at a push they usually feature positive locking and are designed to take abuse. Not very space efficient but you pays yer money and takes yer choice

Don't forget the plug in terminal block option, very flexible

04-09-2010, 12:43 PM
Hi Jonathan,

Shielding the limit switch cables can stop RFI from the stepper motors causing false trip outs. Mk1 Z axis limits (longest leads) kept doing this and was very annoying. I had phonos on that machine, with single core shielded cable using the shield as part of the circuit. This might be the wrong approach, but phonos only have one connection plus earth.

Think I might be better with 2 core shielded, with the shield just earthed, not part of the trip switch but then which connector to use?

thanks, some more ideas there.

Robin Hewitt
04-09-2010, 02:11 PM
Personally I like a screw terminal, much easier to find a screwdriver than a soldering iron when a wire breaks.

If worried abour interference, twist the wire :smile: