Snap Amp Faulting

[axeman]

Hi Tom,

I recently upgraded two computers that run my two CNC routers, and took the opportunity to upgrade Kmotion software from 4.35f to 5.37.
Both KFlop boards were flashed with new version.
I have done this with two machines. One has Kstep which works fine. My other machine has SnapAmps and I now find one of the two SnapAmp boards is faulting.
I can initialise, home, execute a tool change, and run a variety of tool height setting programs. However, after I have set everything up, when I run a Gcode program the SnapAmp driving the X and Y axes starts faulting (SnapAmp fault LED turns on).
The physical characteristics of what is going on is as follows:
No (or only partial) motion in X and Y directions. Sounds like it is enabling and disabling the axes repeatedly every second.
I can also physically push the spindle head without effort during this behaviour.

Zaxis behaviour is normal, with no fault LED illuminated on the Zaxis SnapAmp.

Not sure if this is a result of the upgrade or not. Unfortunately I do not have the old version to go back to.

Any ideas why this might be happening, and what I need to do to solve the issue?

William

[TomKerekes]

Hi William,

I'm can't think of any change that would cause that. Do you have a copy of the previous installation folder? Maybe something wasn't merged into the new Version?

Here is a link to 4.35f.

KMotion4.35f

Please go back to it to see if anything else changed.

[axeman]

Thanks for the link. I have saved the file for future reference.

After re-installing to 4.35f, everything is working fine again.
Most of my customised program files are outside the install folder so I am using the same program files for both versions.

There is a question regarding the file: KflopToKMotionCNCFunction.c which is in the install folder. I used the respective version corresponding to the version of software I was running. Not sure if that might be the issue, but I mention it for your info.
Again, I upgraded to the latest version on two machines, with only the SnapAmp machine having an issue. You might like to check into this a bit further but for now I will stick to 4.35f on my SnapAmp machine because it works for me. Let me know if you think I have done anything strange.

Thanks,
William

[TomKerekes]

Hi William,

The only SnapAmp related change I see is that the Axis OutputOffset is now applied to PWMC (brush motor current mode) where previously it was ignored. If it is 0 it should have no effect.

KflopToKMotionCNCFunction.c has to do with sending commands to KMotionCNC so is very unlikely to have any effect on SnapAmp.

You might post your C Programs, Configuration, and Trajectory Planner settings for us to look at and to understand whattype of system and motors you have.

It seems it only faults running Coordinated Motion with GCode? It might be something with the Trajectory Planning which now makes somewhat more optimized/aggressive motion. Please see if you can find a simple GCode motion that shows the problem. G0? G1?

You might try reducing the Accelerations in KFLOP for Rapids, and in the Trajectory Planner for Feeds, to see if that causes the problem to go away.

You might check how close you are to tripping the Current fault when running moves in the 4.53f.

[axeman]

Hi Tom,

I have installed version 5.37 on an old computer so I can keep my machine running with 4.35f as I need.

With the 5.37 install I ran a few G0 and G1 commands in the manual entry cell and there were no issues.

Ran the GCode file and ended up with the same issue after a second or two.

I've checked the Axis OutputOffsets and they are all set to 0.

I haven't played around with it, but I don't think the acceleration is an issue, as there seems to be no problem with rapid travel when executing a tool change after start up, which is faster than I have the Gcode program running when it starts having problems.

How do I check how close I am getting to the Current fault?

I have attached the files for you to have a look at.

CNC_George_CFiles copy.zip

(1.21 MiB) Downloaded 5 times

Thanks,
William

[TomKerekes]

Hi William,

Since simple MDI GCode doesn't show the problem can you find a simple GCode fragment of code that does?

The KMotionCNC Configuration seems to be for a KStep system rather than SnapAmp. Or I don't see the configured C Programs included. Here is what the Tool Setup Shows.

How do I check how close I am getting to the Current fault?

You might do large sized moves in the KMotion | Step Response Screen and plot what the currents are. You might also try reducing the Peak Current Setting in the Initialization C Program to see if it then fails. Or Accelerating a bit faster to see if it then fails.

[axeman]

Tom, Not sure where that file is coming from. This is my setup screen which you can see references InitSnapAmp4axis_M1.c

Here is a fragment of G code that exhibits abnormal behaviour.

Shooting Board – Fences.txt

(103.92 KiB) Downloaded 2 times

The fault occurs after line N75.

[axeman]

StepResponse results attached:

[TomKerekes]

Hi William,

The Data folder you sent has a GCodeConfigCNC.txt with the references to KStep. Did you send the wrong Data folder? The folder you sent is named CNC_George_CFiles copy. But your Screen references CNC_George_CFiles. Or are you using a custom, non-standard configuration file when launching KMotionCNC? I'd like to be sure I have everything matching what you are actually running before investigating.

[axeman]

Sorry for the confusion. The folder sent was copied, it should be the exact same as original but to be safe, here is the original folder.

CNC_George_CFiles.zip

(1.57 MiB) Downloaded 7 times

The init file (InitSnapAmp4axis_M1.c) is in the KFlop folder. I am not sure how you pulled up the old KStep init file reference.