Using U axis without X

Hi,

I was running my machine yesterday (dual-table router) and since the X table is having some issues we decided to modify the program to run on the U axis table (find and replace all X with U in the Gcode). I found the following issues when not using the X axis:

1. The preview toolpath adjusts to the position of the X axis regardless of the fact that there are no Xs in the program. You can't run the program unless the X axis thinks it's in the right position despite the U offsets being set correctly.
2. The U axis ignored all feed speed commands and moved at the rapid speed at all times. The machine would fly down the U axis and then crawl across the Y axis.

Is this normal behavior for AXIS? Are there tweaks I could make to have both tables usable separately?

Thanks in advance!

Rob

That limitation makes sense and so does your solution. As for the feed speed I could make it slow down with the feed override but that slows every axis.. The U axis was definitely traveling 2-3 times faster than it should have been.

As an aside, I'm trying to figure out RTCP and I can't find the spot where I can enter the pivot length of the machine in the HAL or INI files. I'm hoping I don't have to compile the 5axiskins every time I need to adjust that parameter during machine testing...

Thanks!

I think the standard 5axiskins is actually all I need for the machine but it's just that one parameter (pivot length) that I can't seem to find in any of the documents or the sample configs. Now maybe that's just because I don't know what I'm looking for...

Any help would be really appreciated.

Thanks!

Rob

Sorry, I don't know much about configuring 5 axis kins, but as to your feed rate problems with U. When the new trajectory planner first came out, there were a lot of bugs that needed to be shaken out of the way U,V,W behaved. (I helped find a few with our XYZW machine). Maybe there are still a few crawling around in there. Perhaps it would be worthwhile to try experimenting with 2.6 a little, for a basis for comparison, and see if your U problems are more well behaved.

Thanks for your help!

I think that's what I need. I'm assuming with a little HAL connection magic I could set a fixed pivot length that's the distance from the pivot to the tip of the spindle and then add to that the W offset for each tool? I'm still learning what this stuff is capable of... and it seems like pretty much anything and everything.