Skew and Tracking Adjuster Installed

With the help of John Bernard and his working CNC machine, I was able to take my Sketchup plans to his house and cut out a new MDF roller support panel and the adjustable end caps which should allow me to adjust out the skew easily and resolve the tracking problem once and for all if it is what I suspect it is.


I installed the completed assembly this afternoon and adjusted the roller height and set the two rollers precisely the same distance apart using a digital caliper.


I observed the skew with just one 36" air cut pass moving 3/4" Blue foam thru the machine.
It is about a 1/16" with the bit returning home to the left of where it originated.  This is the same results I have been seeing pretty much most of the time.


With a base established, I ran the adjustment out to spread the rollers apart further on the left side of the machine thinking this should skew the material like a belt sander would do and move the material to the right.


To my disappointment, this did not happen.  The skew remained the same.  


I then opened the rollers so there was about 1/4" difference in the the parallel of the two rollers and again, the results stayed the same.


I then moved the rollers in a 1/4" and no change in the material movement, still approximately 1/16" to the left of the origination point.


Both rollers are within a few thousands of an inch of being the same height on both sides.


I then ran the same test holding the pressure roller up off the right side and still no affect on the outcome.


Now I am totally baffled... 


The adjustment mod worked like a charm as far as being able to adjust the rollers, but the expected results are not anywhere close to what I thought they would be.


I am running out of ideas to try.


The rollers have been shimmed, the hex rods are centered, new pulleys have been installed and centered.  Whatever is causing this is still an unknown.  


In my quest for answers, I have read that there is a lateral motion applied to a turning roller.  Maybe it is just physics and there is nothing more that can be done to completely eliminate it.


I will have to regroup and think about this some more.  I may have hit a dead end.