Okuma MU500V-II/P300 Control - Rotary Programming

[Mick]

Hi there,

Anyone out there programming one of these MU style machines in 5 axis?

I have a question. Are you programming using M16/M116 to control rotary direction, or are you using M404 (shortest path method)?

I got into a discussion with someone the other day, who said shortest path should never be used because you will end up crashing the machine. I've been programming this MU for about 3 1/2 years, and I've never actually encountered an issue with shortest path. Every section of 5 axis code I have run on the machine (and there has been a lot) has been run through Vericut, and it simulated fine.

All our C axis (the 360 degree rotary table) code has the rotary motion between 0 and 360.

I'm just curious on anyones experience with this

 

[Greg Williams]

So how will shortest path crash the machine? M115/116 is a direction as is shortest path. The only unknown variable is which way the table spins if we are at C0 and we tell it to got o C180.

[Mick]

I have no idea Greg. I wasn't the one that made that statement

Interesting scenario though. What happens with M404 when going from C0 to C180? I can't test it because the machine is right in the middle of a cut...

[gcode]

2 hours ago, Greg Williams said:

So how will shortest path crash the machine? M115/116 is a direction as is shortest path. The only unknown variable is which way the table spins if we are at C0 and we tell it to got o C180.

I would expect that Okuma has provided a parameter setting for which direction to go when Shortest path has 2 solutions.

This scenario  could occur at an infinite number of places if a 180° index is commanded

[Greg Williams]

I have never seen a parameter for 180 degree shortest path direction. I suspect this will be out of sight in VOLANTE somewhere. Someone with a machine will need to test it and report back

[Mick]

37 minutes ago, Greg Williams said:

I have never seen a parameter for 180 degree shortest path direction. I suspect this will be out of sight in VOLANTE somewhere. Someone with a machine will need to test it and report back

I've just shut the machine down for the day, but I will check this in the morning

[Mick]

Ok, so I checked this out this morning.

Using M404, going from C0 to C180, the table moves clockwise. Going from C180 to C0, the table moves clockwise.

[Brad Lisle]

The default for the control is to always move clockwise (M15/M115) after power up or reset. However if you command a counter clockwise (M16/M116) move then it will remain modal until clockwise or shortest distance (M404) is commanded, then it will return to force the move back to clockwise.

If you set your post to break rotary moves into quadrants you will never face the C0 to C180 problem. Code will output C0; C90; C180; or C0; C270; C180;

[Mick]

Thanks Brad, that definitely makes sense to break the rotary moves into quadrants.