Install the objective and use a sighting tube or a Cheshire collimating eyepiece
to align it as you would a standard, non-folded refractor.
After the telescope is assembled, I loosen the top clamp on each monopod and adjust the position of the secondary cage until the cross is centered in a collimating eyepiece
. Next, I remove the dust cover, unclamp the mirror, and give the alignment a final touchup using the mirror mount screws.
Even using collimating eyepieces
(S&T: March 1988, page 259), the task can be laborious.