Potential Crash With MPG

[Reedfirst]

Hey Centroid.

Today I was using my Mill and had a quick job to drill a bunch of holes in one location through some thin sheet.

I decided to use my mill in 2 Axis mode and manually lower the Z axis to drill the holes.

I set the Control in 2 axis mode, disconnected my Elrod Z axis drive, and setup my part.

While I was setting up my part I mistakenly turned the knob to "Z" axis and when I rotated the MPG counter wheel it Activated the Servo!

When in 2 axis mode, the Z axis does NOT work on the VCP. But somehow the Z axis is still activated on the MPG.

I completely lost my Z axis position for 3 axis mode and the correct Z reference location for homing the dmm servo using it's built in encoder.

[cnckeith]

thanks for the report.. checking into it now.

[tblough]

Check input #7 when disconnecting the ballnut. It should change states. If it does not, the ballscrew disconnected switch is set incorrectly. When you change to manual Z, F1/F5 turns the motor off, but it's the switch on the ballnut along with the PLC code that disables jogging.

I kept having problems with this because the microswitch is very tough to get set just right. Depending on how it was set, it either wouldn't signal when the ballscrew was disconnected, or fast Z moves would jiggle the switch enough for the control to abort my programs thinking the Z-axis was disconnected.

Check this thread: viewtopic.php?f=20&t=1802

[Reedfirst]

That's pretty interesting. Thanks for posting that.

Mine doesn't have a ball screw disconnect switch. I was under the impression that the software would be able to disengage that axis on it's own when I activate the 2 axis mode.

I think it has something to do with the way the MPG is configured because the Jogging doesn't work on the VCP when in 2 axis mode. In fact if I program something in intercon while in 2 axis mode; The software prompts me to move the axis manually.

I wonder if you are using a different controller or an older system that used that ball screw disconnect switch. Or maybe the input is programmed to trigger 2 axis mode when you release the ball nut.

Do you have to press and "F" keys to activate 2 axis mode or is it automatic when you release the Z axis. I am really curious how your system is set up.

[tblough]

I didn't realize that Dwayne made the Z-drive for Acorn applications. Probably the lack of extra inputs and the need to customize the PLC program had those ship without the ballscrew disconnect switch. The switch was added to the Allin1DC kits back in 2013? to prevent the jog problems.

Dwayne sold his CNC business to Servo Products recently, but he might still be available to answer questions. At this point, don't waste your time with Servo, as they are clueless. Hopefully that will improve with time.