invalid time offset in trajectory buffer

Moderators: TomKerekes, dynomotion

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charliex
Posts: 3
Joined: Sun Nov 15, 2020 6:27 am

invalid time offset in trajectory buffer

Post by charliex » Sun Nov 15, 2020 6:33 am

KFlop, windows 10 x64, 435D and KMotionCNC we'd been testing and all was ok . two axis lathe mode and no issues. then changed to diameter mode and same gcode we'd been running started to say "invalid time in trajectory buffer" happened a couple of times (on our first successful run too! )

its during an arc thats in interpolated by the post XY steps since we disabled arc IJ/R modes because of a mismatch in the arc tolerances (we think), error was along the lines of start = end radius but had ran that gcode more than 20 times with no issues before this new error.

thanks for any input
charlie

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TomKerekes
Posts: 1515
Joined: Mon Dec 04, 2017 1:49 am

Re: invalid time offset in trajectory buffer

Post by TomKerekes » Sun Nov 15, 2020 3:28 pm

Hi Charlie,

I believe that is a bug first introduced in V4.35c. The issue is triggered by multiple GCode segments in exactly the same direction and where one of those is microscopic in length and is filtered out. In this case the updated change in direction is computed incorrectly which results in a zero direction change being "rounded" and causes a divide by zero. Another User found an issue with Version 4.35d regarding Break Angle/Corner rounding with 5 Axis GCode. The same patch should fix your issue. If you're interested the Thread is here.

Here is the patch. Copy this GCodeInterpreter.dll to the \KMotion435d\KMotion\Release folder. Note the file may need to be unblocked before Windows will allow it to be run.

Please let us know if it resolves the issue.
Regards,

Tom Kerekes
Dynomotion, Inc.

charliex
Posts: 3
Joined: Sun Nov 15, 2020 6:27 am

Re: invalid time offset in trajectory buffer

Post by charliex » Sun Nov 15, 2020 7:05 pm

awesome thanks, just ran it twice all the way through. Going to do a few more. I've been going on to everyone about how great Tom at DM is with support and so on after reading here and cnczone for a while now, and now i get personal experience of it.

All we have to do now is configure KMotionCNC Fusion360/tolerances for the IJ arcs issue and I think we're set, probably the worlds most over built HF mini lathe so far, but its in prep for our big manual lathe conversion, really looking forward to constant surface speeds.

cheers!

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