Holey Triangular Calibration

Technical Details
95

Tomorrow is Friday, the lazy day. If the instructions are clear I would invest 3 hours (if that is enough) on Saturday if it helps.
I would need to break a chain I guess. Can do that.

connect the chains together using the master links into a loop, put the loop
over both motors (close to snug, you don’t need to worry about 12 o’clock). clear your log file

G21            ( metric mode )
G91            (relative mode)
B11 R S-63 T 5 ( run the right motor at a bit under 1/4 power for 5 sec )

( if this doesn't take up the slack, repeat until the slack is taken up)

B06 L0 R0      ( set chain lengths to 0)
B09 L5         ( move the left motor a little bit to release tension )
B09 L95 R-95   ( move to the right about 4 inches, leaving a little slack to take up in the next step )
B11 R S-63 T 5 ( run the right motor at a bit under 1/4 power for 5 sec )
B10 L          ( report the position of the left motor )
B10 R          ( report the position of the right motor )

B06 L0 R0      ( set chain lengths to 0)
B09 L5         ( move the left motor a little bit to release tension )
B09 L95 R-95   ( move to the right about 4 inches, leaving a little slack to take up in the next step )
B11 R S-63 T 5 ( run the right motor at a bit under 1/4 power for 5 sec )
B10 L          ( report the position of the left motor )
B10 R          ( report the position of the right motor )

B06 L0 R0      ( set chain lengths to 0)
B09 L5         ( move the left motor a little bit to release tension )
B09 L95 R-95   ( move to the right about 4 inches, leaving a little slack to take up in the next step )
B11 R S-63 T 5 ( run the right motor at a bit under 1/4 power for 5 sec )
B10 L          ( report the position of the left motor )
B10 R          ( report the position of the right motor )

repeat this block until you have finished the loop

what we will be looking for in the log is the lines:
B10 L
[Measure: 199.94]
B10 R
[Measure: 199.76]

and how much they vary over the loops.

I expect that B10 L is always going to be the same (or very close to it), and
B10 R is what should vary.

This is only pulling at 1/4 power, if you add a second B11 line with S-255 that
will run the motor at full power. It would be interesting to have one loop be:

B06 L0 R0      ( set chain lengths to 0)
B09 L5         ( move the left motor a little bit to release tension )
B09 L95 R-95  ( move to the right about 4 inches )
B11 R S-63 T 5 ( run the right motor at a bit under 1/4 power for 5 sec )
B10 L          ( report the position of the left motor )
B10 R          ( report the position of the right motor )
B11 R S-255 T 2 ( run the right motor at a bit under 1/4 power for 5 sec )
B10 L          ( report the position of the left motor )
B10 R          ( report the position of the right motor )

and see how much the two positions differ (how much does the extra power reduce
chain sag and/or stretch the chain)

David Lang

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