Celestron 11 EdgeHD Corrector centering cap

thingiverse

You will need a collimation laser inserted into the visual back of your telescope. The laser points through the baffle tube and out the front of the telescope. You need to remove the secondary mirror by unscrewing the retaining ring and inserting in its place this centering cap. The laser should go out through the hole without touching on the outside edges. Center the corrector until it does and install your secondary mirror again and collimate. I recommend a white material. I used some Hatchbox glow material which is white translucent glow in the dark material.