Chain Sag experiments. Thinking that if you put the sled at 0,0 about, (center of board), and took the bricks off. Assuming that the motors paid out the equal amount of chain on both sides that would put the sled at 0,0 (I would eliminate the current chain sag corrections from the program for this experiment.) without any sag corrections, it would sit somewhere above the 0,0 point on the y, and hopefully ok on the x since both chains should be the same length.
With the bricks removed, the sled assembly with the router weighs “x”, say 7 pounds for discussion. With your new optical measuring cameras, is there a way to lock in on that point, and then record the sled movements as weight is added to the sled up to the brick weights, or even more for the experiment. I’m thinking that the sled should move up and down in a vertical line for different weights. (more or less sag)
At some heavy weight the sag would be almost zero, but that would be too heavy for our motors. At no weight added there would be “more sag” amount. This would be weight dependent. Maybe even take the router off for the minimum weight measurement.
This could tell us values at the center of the workpiece. Then do top center, and bottom center the same experiment. More values.
From that information perhaps a “sag” equation could be derived for the center of the work piece based on the testing.
Hopefully there would only be Y value corrections, and that X was stable.
The experiment could be further tested on an edge top, center, and bottom positions. In these we will certainly have both X and Y movement with different weights to consider.
I don’t know where to go with this until we see some data, but it seems that if we understood the impacts of sled movement with different weights at a few locations we would get some insight into sag. Then decide if this is worth pursuing further to develop our own chain sag “corrections”.
The other thing is this would be a “static” experiment. I don’t know how much, if any, these values would change based on dynamic sag (while it is moving during a cut), cutting induced sag (force on the chain to pull the bit through the workpiece).
Does it make sense to do this? Could compare the measured values to another experiment with the sag calculations in the program, and see what the comparison yields.
Have you done anything like this in the development of the Maslow?