where it needs to be positioned up and down in the slot so that the belt is properly aligned. Note
that this corner bracket will have a little wiggle room left and right before it’s tightened as well,
so make sure the belt isn’t going to scrub the walls of
the opening either when you look for the
perfect place to tighten it down. Now wrap the belt around the other anchor. Get creative about
keeping the bed stationary as you pull the belt into tension. Your needle nose pliers might come
in handy here to grab the belt and pull it tight after you loop it around the stud coming out of the
Anchor Plate. Use a zip tie just as you did on the other side, with the teeth of the belt
interlocking. Get the belt snug, but not too tight. Six or seven pounds of pull tension. Remember:
Floppy belts are bad! Now move bed back and forth with your hand. THE BELT MAY BIND OR SLIP
UPWARDS OFF THE PULLEY, BUT THERE IS A FIX FOR THIS. If the belt tries to run off the idler, the
axle of the idler pulley (the M5x25 machine screw) could be a little canted. Loosen the screw and
rotate it a bit to try make it flush. You also need to make sure the back frame piece is flushed up
to the side frame pieces. If it’s canted back or forward
(IE, looking at corner where side frame pieces and
back frame meet there would be an air gap top or
bottom) it can cause the belt to wander off the
pulley.
Snip excess length from the belt, but leave enough to
work with in case you ever have to do this again.
Now install the NEMA 17 motor mount and NEMA 17
motor on the right frame piece using the same
hardware that you used for mounting the Y Axis
motor on the front frame pieces.
Zip tie the remaining belt section (1040mm) to the
bottom right vertical slot in the X Axis Bearing Plate.
There are a couple different configurations that you
can use to secure the belt, but this is the easiest. Be
aware where you put the head of the zip tie. Zip it so
that the head won’t catch on the right frame piece as
you move the X Axis Bearing Plate to the extreme
end of travel or else you will lose a few millimeters of
travel. Install the motor pulley on the motor shaft,
remembering that it should line up with the belt
without causing any binding. Ensure that one of the set screws is set against the flat part of
the motor shaft.
Now you will install the other Idler Pulley Assembly that you built in a previous step on the left
frame piece. Notice that the mounting hole is counter-bored on the interior side of the Left
Frame. You should mount the head of the M5x25 machine screw into this recess with an M5
washer. Slide the slot of the other Idler Pulley Assembly over the threads, followed by an M6
Page 24 of 35
