Suggestions for calibration

I’ve just run through calibration and have the following notes/observations:

  1. Hot keys would be useful for the buttons on the screens. I have a wireless keyboard which means I can be over by the machine, but viewing a mouse pointer at 4m isn’t easy
  2. The first time through, as I knew nothing at that point, it would have been useful to have been explicitly told that there’s no sled attached to the chains at the start of calibration. Later, I knew this, but first time through it wasn’t obvious.
  3. On a similar vein, it might be useful to indicate that the chains shouldn’t be unhooked from the sprockets until calibration is complete. Again, once you’ve run through once it’s clear.
  4. I’m not clear (still) on which hole to attach the chains to on the sled brackets. Is this explained somewhere?

Just posting that there still is a need for a detailed calibration tutorial on the Wiki.


Not sure that it’s explicitly mentioned, but choose the holes on the sled that make the chain parallel to the work surface. The goal is that the chain meets the motor sprocket straight on in plane.

I just posted this on another thread:

You need to have the chains near the CG of the sled (Center of Gravity out from
the workpiece), if you have them too close to the sled, it will tend to pull the
top away from the workpiece, if you have it too far from the sled, it will tend
to pull the bottom away from the workpiece.

a larger sled reduces this effect, but you really want it balanced.

Once you have this mounting height set, then you need to make your motor mounts
hold the motors far enough out so that the chains are (fairly close to) parallel
with the workpiece or you run into the problem of them climbing off the
sprockets (as you ran into)

So move the chains out to where things are balanced, and then move the motor
mounts out to match