delta corrections do not seem to have an effect. (fw: rev 1.0.0dev)

edited February 2017 in Motor Control
So I am still fighting to get my delta to print outside its sweet spot in the center of the bed.

In frustration I pulled all the hot end equipment from the effector and put on a flat plate just to see if things were level anywhere.
This is actually similar to how I tram my mill so it seemed like it would at least give me an idea on the printer...

What I found is that in the Y axis, (which is moving toward and away from Tower Z (C tower) my effector moves like a pendulum...however it
doesn't move evenly as it crosses the zero point...

In the center it is basically level as it moves away from the tower it develops a minor tilt with the outer edge moving up.
near going the other way it develops a major tilt on the order of millimeters over the 10mm plate length. The tilt here also has the outer
edge rising while the inner edge falls.

I can understand that if the effector moves away from the tower the number of steps per mm of travel changes awn the arm angle changes, which is probably why on one size of zero the problem is more pronounced than the other.  It is almost like the belt is moving at a different

Movement on the x axis is much better...still a little pendulum effect but nothing like the Y.

Everything mechanically good no unreasonable play.  Rods all seem the same length as close as I can measure.
Tower are vertical and positioned as near perfect as I can measure and are held my machined AL braces so I think they are good.

Possible there is some belt stretch but I don't see how it could be much on a toothed belt...I tightened and loosened them but no real change is seen so I am back to moderately tight on all three.

I figured I would play with the Horizontal Rod and Diagonal rod correction factors...however they do not seem to make any difference at all.
Does something need to be set or reloaded or something for eprom changes to the values to take affect?  I started out with .1mm changes when that didn't help I jumped to mm then 10mm and still no visible change in motion....and I would have thought that would make a huge difference. I typically build the firmware with all the auto level and correction features off as for now I am trying to make mechanical corrections, but since I can't seem what more I can fix I thought maybe these parameters might give a hint as to what is wrong.

It seems like maybe the arm length or the h-radius might maybe be off on that Z/C tower causing the movement problem.

Any ideas how to get the corrections to take affect or what else might be wrong with my machine.  I have been playing with this for years but
never can I get it to print evenly outside the inner circle and part of the reason I went delta was to get a bigger area.  This latest test with the hot gear out show me there is clearly a major problem which is why endless tinkering with software and hardware leveling has fixed it.


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