Good progress, maybe look at using a rotary encoder on each stepper, it doesn't need to be high resolution 2 to 4 bits, could be made with acetate sheet and tape or printed, the acetate being a small disk that is glued to the shaft stub on the bottom of each stepper, that way you would get a ball park idea of where the arms are at start up before even moving, has the added advantage that you only need to move to the resolution of the encoder to home.
An encoder wheel is a great idea! Unfortunately these steppers don't have a shaft on the reverse side, they're cut flush with the bottom bearing inside the stepper. However an encoder on the bottom of the arm 2 drive pulley could work well. I'll have a think.
Good progress, maybe look at using a rotary encoder on each stepper, it doesn't need to be high resolution 2 to 4 bits, could be made with acetate sheet and tape or printed, the acetate being a small disk that is glued to the shaft stub on the bottom of each stepper, that way you would get a ball park idea of where the arms are at start up before even moving, has the added advantage that you only need to move to the resolution of the encoder to home.
An encoder wheel is a great idea! Unfortunately these steppers don't have a shaft on the reverse side, they're cut flush with the bottom bearing inside the stepper. However an encoder on the bottom of the arm 2 drive pulley could work well. I'll have a think.
en.wikipedia.org/wiki/Rotary_encoder got a lovely scalable, printable svg :) good luck
Keep the good work up
Cheers!