5 axis CNC Router/3d printer

[George Butty]

Thanks Tom, I have been doing something close to this. This gives me a better
idea of how to go about it sytematicly. Will let you know how it works. One thing that does make this frustating is the stop starting of both axis B and C
in either G49 or G43.4 H1 mode. H1 set to 6.45" . I know you tried looking for the problem but it is still there.
Just a recap. When Kmotion CNC is started, I start INT and then I send machine to home. Works fine every time. I jog to a random
clear position on the machine. Manually zero all axis. Then I rotate B or C in RTCP 2 to 3 times. No prblems. I take measements
with dial indicator to zero physical positions. Then I make corrections to the zeroing of say C axis using a home C.c program which sends C axis to zero limit and then sends axis back to dial indicator zero. (Shifting zero location in C) I make count changes to C axis zero count to reposition C axis. I have to move the head of the machine so I don't hit the dial indicator as C rotates. Once C.c finishes, I move head back to the dial indicator
using the manual jog arrows or the manual step button. Then when I activate (MDI) say B 90 axis to rotate, ( this is where I measure if the C moves off the Zero of the dial indicator while rotating in B) ,the B Axis will rotate at a slow speed with stop, starts before getting to position. Seems to get to position every time. Once the rotation was completed, repeating the B 90 or B-90 rotation works fine until I manual jog or manually step again. Once I jog, does not matter what direction, the stop start of rotation is activated again and cancels on 2nd rotation.
The other way I would prevent the stop start would be to send the angle at which the head is located which would not do anything and then send the angle I want as the second move. (if the head is at B0 then I would send B0 and then send say B90 to get to B90 without stop start. That cancels the stop start) The other thing that it would do at times would reset the zero position of the rotation. There are times that the homing zero would reset to the first rotation postion. If I send in MDI say C180 it would stop start and get to position. Then for some reason that C180 automaticlly gets set to Zero. I have to send C-180 to get it to the proper Zero. The only way to correct this is by rezeroing the complete machine. Also the machine is a head/head machine with no table movement. Sorry for long winded explanation.

George

[George Butty]

Hi Tom , here is links to videos. Both B and C rotations are simple B90 and C180 commands in MDI mode.

https://www.youtube.com/shorts/N9XE1Qc_vr8

https://www.youtube.com/shorts/zgW-13B38so

George

[TomKerekes]

Hi George,

Thanks for the long winded explanation.

I'm able to duplicate. Please give me some time to analyze what is happening.

[TomKerekes]

Hi George,

I think we found something. Its somewhat difficult to explain. It has to do with the way the GCode Interpreter syncs to the current machine position when GCode (or MDI) begins execution and numerical round off error. The current absolute Machine position is read and converted to Interpreter coordinates by basically subtracting GCode offsets. When GCode commands motion the Interpreter coordinates have the GCode Offsets added back in. Subtracting and Adding the same number should theoretically not change the number, but when performed with limited precision can, especially with large offsets. Offsets are created when an axis is "zeroed". This can result in a change from something like "B90" to "B90 X0.0000000000000001" which are treated much differently in GCode.

Here is a patch for Version 5.3.1 that should prevent the issue. Copy to the \KMotion\Release folder.
GCodeInterpreter.exe

If you would like to re-build the Libraries here is the source file with the change
GCodeInterpreter.cpp

HTH

[George Butty]

Hi Tom, now that you mention this I also did notice in the position offset data (G55) would come up with
a value of 1e6 when it should have been zero.
I am running 4.34. I guess the best thing would be to update to 5.31?

George

[TomKerekes]

Yes please update.

[George Butty]

Hi Tom trying to update to 5.3.1. I get two errors
mismatch yes or no ?
Will not connect to kmotion server? please check attached.
Also help will only work on line. Do I need to remove 4.34h?
USB driver 4xx
George

[Moray]

You'll need to ensure the KFlop/Kogna is updated to the same version of Firmware, however there is an issue if you're going from 4.xx to 5.xx - https://dynomotion.com/forum/viewtopic.php?f=9&t=1706

And also see viewtopic.php?f=12&t=1708

I used the Recovery option to update the KFlop that I'm using for testing just now.

[George Butty]

Also my version of Kmotion is loading as a 32bit app. Is this correct? or should it be 64bit version.
George

[TomKerekes]

Hi George,

The 32-bit Versions are fine.