New Build, Aluminium Frame Router/Mill

**Davek0974** · 12-03-2016

We have motion :)

Running a square at the limits...
https://youtu.be/tZ2FtlGJOf4

Air-cutting a 280mm circle...
https://youtu.be/fF-aAMadkAw

There is a frightening amount of power behind those axes, I tried applying some load but even with me forcing it as much as i could it made no difference :)

Then i moved on to limit switches - X first, using inductive sensors...

My brilliant idea was to use one sensor on the moving part of the axis and have two adjustable targets, all good so far;)

Got that lot fitted and set X++, X-- and X-Home all to one input (this was the smart bit I thought)

But....

The limits work but I cannot jog off of either end - it just shows "Limit switch triggered" immediately after pressing Reset, and the home works but immediately throws a limit fault after homing.

So...

Am I correct in now thinking that I am indeed a twat and you must have TWO sensors or have I missed something simple??

These sensors seem to not flip on or off - they flicker a little as the target gets near - is this normal??

Close but no cookie yet :)

Here's the rough lash-up of my panel...

Click image for larger version.

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**Clive S** · 12-03-2016

Am I correct in now thinking that I am indeed a twat and you must have TWO sensors or have I missed something simple??

Brill it is always good to see it move for the first time .

You only need one switch if it is traveling there is a checkbox in Mach3 so that you can jog off the limits. On the setting page I think but I would have to check

**JAZZCNC** · 12-03-2016

Dave go into General Config and turn off "Home With safety" then you can share the swithces for both.

Then turn on Auto limit overide and you'll be able to reset limit when triggered and jog off.

**Davek0974** · 12-03-2016

I thought that too, the only one i could see was "Home SW safety", tried that but made no difference.

These sensors seem to not flip on or off sharply - they flicker a little as the target gets near - is this normal??

Maybe the flickering is causing the issue and I've bought a load of crap sensors??

**JAZZCNC** · 12-03-2016

what kind of sensor.?

**Davek0974** · 12-03-2016

Originally Posted by JAZZCNC

what kind of sensor.?

These ones, they seemed to be the most common type, NO, NPN.

LJ12A3-4-Z/BX

**JAZZCNC** · 12-03-2016

Originally Posted by Davek0974

These ones, they seemed to be the most common type, NO, NPN.

LJ12A3-4-Z/BX

How are you connecting the switches to the BOB.? What pin does the Black wire go to.?

**Davek0974** · 12-03-2016

On my CP0-10V bob from CNC4YOU it goes to pin 10 and i am using input 10 in P&P settings, you can see the LED on the back of the sensor flicker as the target is starting to cover the end of the sensor, when fully covered the LED is on stable.

The sensors are powered from the 12v output on the BOB as shown in their diagrams.

**JAZZCNC** · 12-03-2016

The manual shows PNP swithces and your using NPN. Take 12V to pin 10 and Put Black wire to Gnd. Then it will work.

**Davek0974** · 12-03-2016

Originally Posted by JAZZCNC

The manual shows PNP swithces and your using NPN. Take 12V to pin 10 and Put Black wire to Gnd. Then it will work.

This is the manual i used http://cnc4you.co.uk/resources/CP0-10V.pdf, the switches and sensors pull the pins down to activate, I guess thats active low, and i thought NPN was sink or active low output i.e the pin is pulled high internally and the sensor pulls it low?