[de_]

Thanks for the great overview. You confirm alot of what I suspected.

We actually designed in both an encoder and a 10 turn pot to give us 2 different things to program against (one perhaps as a backup). We are really concerned about momentum/gravity based on a past bad experience.

The encoder was easy to mount (small). We were going to use either a limit switch or a initial starting position to give the encoder a known location.

The 10 turn pot needs a big sprocket and we are currently having trouble finding unimpeded space to mount it (but we will).

We were wondering if there are any MATERIAL accuracy differences between the 2 approachs re a P or PD loop. The encoder is 250 ticks per turn say 15 turns = 3750 over say 100" = 0.03" per tick resolution. The Burns 10 turn pot accuracy/linearity is standard (forget what but probably 5%). The AI system I sort of remember is 10 bit (1024 values) over say 100" = 0.1" on a perfect day, probably better to plane for 0.25 ?