ToolsUnclamped Sensor - Power Drawbar

[richardb15]

I've been getting into this with my Bridgeport that uses a petal clamp, beville washers and the hyd/air intensifier cylinder on the top of the drawbar. There are 3 possible positions to be aware of. Total movement of the drawbar top, dictated by the washer stack, is 9mm so similar to the 0.3" mentioned above. Without a tool in the spindle and cylinder retracted the position is +9mm. Cylinder energised and therefore clamp open and tool released is 0mm. Tool inserted correctly and cylinder released should be +5mm. I have a single prox sensor that detects off a steel ring just under the top drawbar lock nut. The spindle is safe to operate in the no tool (+9mm) and tool correct (+5mm) locations. It is not safe to operate and therefore interlocked off in the cylinder energised, or tool incorrect positions. Tool incorrect is when its half clamped so absolutely not safe to turn on the spindle. The prox can therefore be set so any position above 5mm with cylinder not energised is okay to run.

[Ken Rychlik]

Basically one sensor will do both. The hsd spindles I use on routers have both tool holder in and tool holder out sensors. Depending on inputs, I sometimes use one of them with M101/50007 or M100/50007 (waiting on input 7) One is waiting for it to be open and the other is waiting for it to be closed. So it it's not open, it's closed and vice versa. Anyway this is just in the M6 macro and it will stop and say waiting on input 7 if it's not correct. You have to know what input 7 is but still if it's not doing what it's supposed to it will stop.

[cncsnw]

If you want a message different from "Waiting for Input #7 (M101)", you can put a custom wait message in your cncxmsg.txt file.

The format of the cncxmsg.txt file is simply pairs of lines: the first line is the PLC bit that you might be waiting for, and the second line is the message to display when waiting for that bit.

Code: Select all

INP7
"Waiting for tool unclamped"
INP8
"Waiting for tool clamped"

Unfortunately, there is no syntax to distinguish between M101 (wait for closed) and M100 (wait for open), so if you use only the unclamped signal, and you use it with both M101 and M100, you have to make the message generic:

Code: Select all

INP7
"Waiting for tool unclamped/clamped"

You could get around that by defining one or two memory bits in the PLC program to echo and invert the tool-unclamped input, then make the CNC macro and cncxmsg.txt file refer to the memory bit instead.

[RJS100]

Hey Marc,

I am all done with almost all the parts for the ATC and bracket to support it. The final piece is the sensors for the drawbar. Since there are new changes coming in the near future with CNC12 version 5.40 and 5.50, I used your suggestions to design brackets that will allow me to use proximity sensors to read the unclamped and clamped position of the drawbar. Here is an image of it. Thanks for your input!

3D Image: https://a360.co/4lnCrys

Best... Richard

[cncsnw]

Looks good!