Hi Yasushi,
We had the same problem on the C14 Edge at the Mauna Kea VIS here in Hawaii. ?I talked to Dean at Starizona and he said the secondary notch may not be at the three o'clock position as some of the earlier models were, but the Fastar logo should be level with the scope horizontal. ?The secondary cover should be rotated to hide the collimation screws. ?When we did that, the notch was at the three o'clock position. ?You can tighten the secondary tube without removing the corrector plate, but it's tricky and works best with two people. ?You should get it as tight as you can by hand, but it will probably loosen again. ?Dean has an improved gasket that will solve the problem, but you must removed the corrector plate to install it.
Hope this helps.
Don
