Mach3 jog parameters

[bhauser]

Hi,

It's been a long time, but I've finally decided to take care of an annoying problem with the limits on my setup. The limit switches on my mill cut power to the drives, so when they get triggered it's a process to re-enable the system.

I've finally set up my soft limits, which I believe will prevent g-code from running past the limits, however the Jog keys in mach3 allow me to run into the limit switches under certain conditions. If I step slowly towards the limits the table stops. If I move fast enough towards them then the table doesn't decelerate in time and the limits get triggered. Where can I make adjustments to the Jog accelerations and velocities. Also, can I change those settings based on table position so I can slow the table down near the limits?

Thanks,

Brian

[TomKerekes]

Hi Brian,

There is an example AdjustSoftLimitsTest.c which includes AdjustSoftLimits.c which calls CheckDistToStop() which should cause a stop based on speed and acceleration to stop at the last moment to always stop at the soft limit. Once working add the calls to your forever loop so another Thread isn't required.

HTH

[bhauser]

Thanks Tom,

I'm still running 4.33 and this example seems to be new with 4.34. Are there any changes in 4.34 that might require changes to my control code? If it's an easy upgrade I might as well run the latest...

-Brian

[TomKerekes]

Hi Brian,

I can't think of any needs for any changes. Some of our later code may have issues running with Mach3 on Windows XP. Keep a copy of your 4.33 directory and you can always go back.

Our latest test version is here.

HTH

[bhauser]

Thanks Tom,

I'll let you know how it goes.

-Brian

[bhauser]

Thanks Tom,

Upgrade to 4.35f was uneventful and the adjust soft limits fix works great! I still have questions about about where to set the Jog parameters though. How do I set the acceleration/deceleration and velocity for the Jog buttons in Mach3? Is this a Mach3 setting or a Kflop setting?

Thanks,
Brian

[TomKerekes]

Hi Brian,

Thanks for reporting back.

How do I set the acceleration/deceleration and velocity for the Jog buttons in Mach3? Is this a Mach3 setting or a Kflop setting?

The KFLOP Accelerations and Jerk are used when Jogging.

[bhauser]

Thanks Tom,

Are these also the base accelerations for the g-code commanded moves? Should these be as high as the system will tolerate?

thanks,

Brian

[TomKerekes]

For Rapids yes but for Feeds no. Those are set within Mach3. You might read this. It is written for KMotionCNC but also applies to Mach3.

[bhauser]

Thanks Tom,

I really appreciate your awesome tech support! I have to admit that I'm not quite getting how the 2nd order g-code commands deal with acceleration. I'm not a motion control guru, but I've tuned my fare share of motion control systems. I think I have a reasonable understanding of how Jerk affects motion and "infinite" jerk makes sense to me. I'm just scratching my head because I can't find an acceleration parameter in Mach3... I thought this would be under the motor tuning configuration, but that page doesn't open... presumably because of the kMotion plugin. For servo systems don't you need an acceleration parameter? If it doesn't come from the kMotion axis configuration, then where does it come from? Do I really not need one?

Thanks,

Brian