Ultimaker UM2 Assembly Manual page 15

13.
Take the other short axes and slide it
through the hole back of the left pannel. Then
take the dubble pulley and place it on the axle.
14. Place the sort timing belt on the dubble
pulley. Make sure it's on the side closest to
the frame. this short belt will attatch to the
motor later on in the process. Now take the
long belt from the left sliderblock and place
it around the pulley.
15. The dubble pulley is followed by
an assembled sliderblock and then
another pulley.
16. Put the right timing belt around the
pulley on the back axle. Then slide the
10mm spacer around the axle. Now slide
the axes through the frame until it is flush
with the side.
15