Rotrics studio pen positioning & measurements

This is a real newbie questions, but what is the relation of Rotrics Studio grid positions to real world positioning? Following the drawing setup guide I put an 8.5"x11" paper in front of the arm. I measured 15cm out from the black part of the base to the bottom of the paper. The guide wasn’t clear whether to measure to the center of the paper there, or bottom.

  • Rotrics studio shows an arc of where the arm may move, but what are the units - mm?
  • If so, how does it align with what I see in Studio?
  • From where do I measure? I thought the “home” position would be the center (you can see a black blob of ink where I set the start position from pressing -Z until it touched down)

Sorry for the basic question

This is an educated :wink: guess:

  • The units are definetely mm.
  • When I move the DexArm to the y-position as near to the base as it can reach, at a position of Z = -60 (measured from “Home” position), the tip of the pen is about 145 mm away from the front of the base plate. When I move it so that the tip of the pen is 150 mm away from the front of the base plate, and take 230 mm from that position, I land at the centre of rotation of the arm. That teaches us:
  • 150 mm/15 cm to place the lower edge of the paper is measured from the front of the base plate.
  • The numbers in Rotrics Studio are measured from the centre of rotation. Y=0 is never reachable, thus, and anything below Y= 230 isn’t as well (that is with X=0 and Z=-60).
  • The reachable coordinates in Y are dependent of the coordinates in X. Positioned at X=+/-70, a position of Y=220 is reachable.

There is a lot of confusion about the Y coordinates, and actually I didn’t use those in my test. The “Home” position seems to be at Y=300 (mm), which transfers to Y=0 when you set work origin at “Home” position.
This is consistent with the “blob” in your drawing.
I don’t know why Rotrics are using such quite uneasily to understand coordinates in Y, when those don’t clearly translate into distances on the paper, especially if we use the “Home” position as work origin, where Y=0 for all practical purposes.

thanks, Eldkatten. You’re 2 for 2 with answering my questions :slight_smile: