Centroid Community CNC Support Forum

I was just doing the final assembly of my ATC, when I stumbled on a BIG mistake . I converted plans for this ATC to make it CNC12 compatible. To do so I added a proximity sensor & CAM to feed the appropriate signal to the "ATC_ToolCounter" input needed for CNC12.

I started putting the fork assembly on the ATC when I noticed that the if I insert a tool in the fork, the top of the tool holder will hit the part of proximity sensor

The proximity sensor I am currently using is an 8mm proximity sensor with a 4mm sensing distance. The overall body length of the proximity sensor is 45mm long.

The simplest solution to this problem is to use a much shorter proximity sensor. The tool holder will clear the proximity sensor if I can find one with a shorter body.

Current Proximity sensor being used (45mm long body & 4mm sensing distance):
https://www.automationdirect.com/adc/sh ... /ae1-an-4a

Alternative proximity sensors with approx. 35mm body & 4mm sensing distance:
https://www.automationdirect.com/adc/sh ... /ae6-an-4a
https://www.automationdirect.com/adc/sh ... -ad-631-m8

Automation direct has two other sensors that are 35mm long. This is just a bit too tight for comfort.


I did find this one https://www.automationdirect.com/adc/sh ... /aes-an-1a, but the sensing distance is only 1.5mm. The material influence factor for aluminum (the cam is made of aluminum) is .45

Can you recommend another source for a proximity sensor that is shorter?

Thanks... Richard

Maybe try a rectangular sensor?

This one might even fit between your existing mounting plate and the cam:
https://www.automationdirect.com/adc/sh ... d-611-c12p

Thanks Marc. Really Really appreciated!

This looks like it may work but Automation Direct does not specifically list it on the Material Influence chart. Similar model number have a .50 factor for aluminum, so if it is the same as these... This is a home run!

If that doesn't work out for you, the smallest proxys I've personally seen are for rodless cylinders. Usually mount in a track and have a 1/4 turn locking cam.

I've got a double-handfull laying around from re-purposed cylinder slide projects. Note that all of the ones I've seen (or have) are side-sensing, not end-sensing, so they would give you a tone of clearance for the ATC cam.

All the big players offer them - Festo, Parker, Bimba, etc.

I don't have part numbers to provide, but like a lot of industrial lego stuff they aren't hard to find once ou know they exist.

Thusly:

Marc,

You made my day. The rectangular sensor with a small 3D printed spacer will fit perfectly. I will call Automation Direct tomorrow to see how this sensor work with aluminum. Worsts case scenario... I will remake the cam out of steel.

See attached.... And THANK YOU!

PS: SPUMCO.... Thanks for your suggestions on those real small sensors. I am sure I will use them at some point.

You can drill a hole in the cam to insert a small steel piece.

Uwe

Thanks Uwe, I drilled a hole on the sensor for my drawbar, and it worked well.

For the ATC, Marc suggested using a CAM shape to give the sensor more time to sense the position. If this is necessary, drilling a hole in the CAM would not have the same effect.

Richard

Aluminium will be ok with the DW-AD-611-C12P but distance is reduced to 2mm.

https://cdn.automationdirect.com/static ... luence.pdf

Uwe

suntravel wrote: ↑Tue Aug 26, 2025 5:20 am Aluminium will be ok with the DW-AD-611-C12P but distance is reduced to 2mm.

Uwe

In some situations this reduced distance can be A Good Thing, as the shorter sensing distance will give a more accurate and repeatable detection distance. For instance, as a homing sensor, that would be helpful. On one of my machines I used proximity sensors for home and limit switches with aluminium targets.

Sounds good. Now that I have an extra proximity sensor, does anyone know if the new CNC12 version 5.40 will natively support a "ToolClamped" sensor?