Heritage secondary mirror alignment

[Nick-In-Ireland]

Back again with more questions  ;-D

I have collimated my Heritage 130p the best i can with a colli cap, the pic below shows that my secondary is slightly twisted :-

This slight twist is on purpose to achieve this level of optical alignment :-

Without this twist of the secondary mirror holder my collimation is as in this pic :-

So my question is, is it better to keep the slight twist of the secondary, how critical is it for good sharp views ?, the only other way is to remove the secondary holder and bend the rod that connects the scope to the secondary holder so i can achieve the correct position without having to have the twist, no spider vanes on this scope remember..., i don't want to do this because getting the bend right will be v.difficult and things may be acceptable as they are now? hence this post.

Is it better to have the slight twist of the primary holder and all the circles lining up down the focuser or is it better to have the secondary holder straight and eyeballed in but with the mirrors not all aligned as in the second focuser pic.

Nick.

[Peter Drew]

I would twist it so that the mirrors appear concentric. 

[Jason D]

Collimation is about aligning optics -- not about mechanical alignment. Centering/rounding the secondary mirror under the focuser is part of the optical alignment since you will eventually have an eyepiece in the focuser. Your setup with the secondary mirror centered/rounded is what you want. It is irrelevant which mechanical part you twist to move the secondary mirror to the center. It will not make a difference in your case.

Jason

[Digger1895]

My first collimation of myHeritage 130p was due to the secondary taking a bump and becoming loose.

I used a colicap then Cheshire and it looked spot on. When eyeballing after it seemed the secondary had twisted slightly in relation to the focusser. I left it and tried the scope later and it worked perfectly.