Access Probe Changer Mount Point From Inside Program

[mbatten]

Hi Everybody,

Does anyone know if there's a way to access the probe changer mount point (where it goes immediately before and after changing tips with the rack) in the code for a program? I'm thinking of shaving off a few seconds by using a MOVE/ALL command on the way to and from a tip change, but I need to know where to send it to. It would also be nice to be able to send it to that point at the end of the program without having to actually change tips.

Thank you!
Matthew

Edit: Upon further investigation, it's more complicated then I thought: it looks like the XYZ numbers in the "Mount Point" tab under Calibrate/Edit > Probe Changer are to the end of the quill, not the position of the probe tip. This would fit with how the machine moves prior to a tip change; however, replicating that action in the program requires either getting the machine to move the end of the quill to a point or manually de-compensating for the length of the probe (a big pain).

[Douglas]

I think this is pretty much what MOVE/CLEARPOINT does, you define the point in parameters CLEARPOINT tab using machine coords I believe not probe compensated

[mbatten]

No, he means CLEARPOINT. It's a thing - I didn't know it wasn't compensated, though.

[louisd]

oooh looking at F1 for clearpoint now, learned something new today, thanks Douglas, and my apologies.

[Douglas]

I'm not 100% certain how or if it is probe compensated, but I was able to get Z+ when I do a read point with a fairly long probe so it was my assumption I guess

[louisd]

The concept of moving to a standardized location at start/end of each execution has been a concept we've considered several times. Ultimately, we decided against it because we often have to execute the same measurement routine multiple times. Adding a move command to the rack mount point, or a top corner of the volume, will be wasted motion in these instances (of multiple routine executions).

We also considered making a rack location empty and physically loading a 'no-probe attached' to remove the module from the body at end of each routine.
Again, it simply results in more cycles loading/removing from the rack, more probe head un-seat/re-seats, and more run time in practical use.
--The more you tell the CMM to move, the more it will eventually move.

Typically, at the end of each routine I just have a move/increment +10 to +15 inches (or so) in Z. That way, it's a direct unobstructed traverse to the mount point if a new probe needs loading, and/or it provides ample clearance for operators to swap fixtures or remove/replace parts in fixture that's already on CMM.

[Douglas]

I'm thinking you should be able to use those mount point coords as the clearpoint definition and use Insert > Move > Move Clear Point .... curious if this works please let us know

[mbatten]

Thank you all for your thoughts! I messed around with clearpoint a little this morning. Unfortunately, as referenced in this thread, the clearpoint position is a per-user setting. I would really like to be able to set it inside my program so I can change it if I'm working with a really tall/large part. It also brings along with it the danger that one of the operators will foolishly log in as the wrong user (it sounds ridiculous, but it has happened here), bringing up the home position as the clearpoint coordinates and potentially causing a crash. We need to lock that down anyway, though.

louisd, we're currently moving in Z+ and Y+ at the end, which we need to do in order to provide adequate clearance to change things out. One of the previous programmers here always changed to tip 2 at the end of the program, I think to avoid bugs in earlier versions of PC-DMIS that caused it to forget which probe it was holding, but it also caused a consistent program end position. I haven't changed tips (and don't want to) for reasons of time like you mentioned, but it would take very little extra time to move back to the probe change position compared to what we do now. I'm just a bit frustrated that CLEARPOINT doesn't give the programmer tighter control over what's going on.

I would simply recall the startup/machine alignment and put a MOVE/POINT there, but I don't know of a way to put the quill/arm at that point and not the probe tip. I suppose I could figure out the code to reverse the tip compensation and put that in a subroutine, but that seems like a very inelegant solution for a very simple problem.

[Sora5]

You can simulate this with an external alignment. Create an external alignment at the mount point, recall it in your program and movepoint 0,0,0.

[mbatten]

But is that compensated for probe angle or not?

[Douglas]

slick workaround, never realized it was a user setting as multiple users is not really a big thing here

[mbatten]

The other downside to CLEARPOINT that I forgot to mention above is that it doesn't give me the option to use a MOVE/ALL command to go back to it. If that's the way it is, though, that's the way it is.