I seem to be dealing with a bug in either TinyG or tgFX in relation to starting a run. If the 'set machine position' is set and nothing is jogged prior to running, all works fine. But if the Z is jogged at all after 'set machine position' then the first drop back down into the run is foreshortened by the depth increment, however subsequent moves correct this. The error only occurs on the very first drop into the material. The error can be avoided by either never jogging the machine after the 'set machine position' (but this can be difficult without some alternative method to set the Z height) or creating some extra initial machine action prior to all the actual ones which absorbs the error prior to cutting material. If anyone else has seen this and has suggestions better than my work arounds, please share.
Also, when the job is complete, the values of the XY and Z get reset randomly making rezeroing very difficult, and it does not return to the zero origin, it just stops above the last tool move. Are fixes or workarounds for these issues available?
I am running tgFX 2404 edge, and I have a tinyg only about 2 weeks old, but not sure about firmware.
I just tried this but I am not fully understanding what it is you are seeing. Also can you post the gcode that is "resetting" your x an y at the end of the job?
If you would not mind. Could you make another post detailing how to reproduce this exact bug? Also please detail what you think should be happening.
Thanks and sorry for your issues. We will do our best to get this fixed asap.
Here is a link to a video with proper operation, run immediately after zeroing. The z drives to 3mm above part, then makes the first pass at -1mm, then -2mm, then -3mm, then -4mm, finally -4.9mm, then it completes the job, and resets the X Y and Z positions to random numbers.
Here is the link with a 1mm jog of the z axis above the part, then the exact same run. Note that the z drives to 3mm above part, then down to +1mm, then down to -2mm on the next pass. It should have driven to -1mm just like the first video.
We will keep looking at this. I think Alden and Rob (primary devs on TinyG) suspect where this is occurring at. However I will talk some more with them.
Thanks for the great video's this is the kind of troubleshooting that really helps us understand and get to the root cause more quickly!
ril3y
This topic is from the original forum (February 2014). Your reply starts a new discussion linked to it.