New scope on way. Collimation thumb screws.

[paul schofield]

Good evening all. So I have ordered my new telescope from R.V.O.. and am soon to be the proud owner of a Bresser Messier nt-203 exos 2 goto scope.  I have been hitting Google pretty hard trying to find out the correct size collimation thumb screws I will need for not my primary and secondary mirrors. 

 

I don't really want to spend silly money on Bob's knobs.  If anybody can advise that would be great. 

I have also checked the online manual to no avail. I think, but a not 100% sure I may need M4 thread x 30mm size for the secondary mirror ??

Does  anybody own this scope. I would greatly appreciate any advice. Thanks all.

[almcl]

Not familiar with that particular scope, but if it's anything like my Skywatcher, you shouldn't need to purchase screws for the main mirror - they should be knurled already.

For the secondary (assuming yours are again like the SW) something of a suitable size from here might work (not sure if the nylon will be stiff enough).  I actually used stainless and painted them matt black.  From memory they were either M3 or M4 but yours may be different?

Edited January 8, 2020 by almcl

[johninderby]

Think Bresser may now be fitting colimation knobs on the seondary of the 8”and the mirror cell is a 6 point wth proper adjusting knobs.

 

Edited January 8, 2020 by johninderby

[Alan64]

For the secondary-mirror, the hub, I take one of the recessed set-screws(for sizing up) to my local hardware and get socket-cap screws(thumb-screws essentially)...

The white-arrow points to a white-nylon washer that I epoxy on the back of the secondary-mirror's stalk.  That gives the set-screws something to dig into besides the soft metal of the stalk.  Without it, the set-screws make dimples in the metal, making it difficult to create new, slight re-positionings of the mirror.  The screws will simply want to slip back into the dimples of an older collimation position; a simulation...

Edited January 9, 2020 by Alan64

[joe aguiar]

I wouldn't even mess with the collamation most scopes hold it very well. Theres somtimes a lot talk about it in forms but for most new people that kinda difficult to do.

Unless it gets a big bump it should be fine. You can test it if you like in a star.

Joejaguar 

[paul schofield]

Thank you for your help guys.  I generally collimate or at least check collimation prior to a session.  Will do with the new scope too.  Fingers crossed for perfect collimation and clear skies. Thanks again.