8 replies to this topic

[ZL4PLM]

just about to pull the trigger on one of these.

 

whats the best approach to collimating a truss RC ??

I've seen a few approaches now .... and I don't own CCDinspector or maxim DL

Cheers

 

Simon 

[tonyt]

Part way down this page is a collimation instruction by the guys at Teleskop Austria:

http://interferomete...retien-gso.html

 

There is a lot of interesting information on that page - well worth reading thoroughly.

 

I have been told that keeping the focuser collimated on these can be difficult.

[ZL4PLM]

thanks 

 

The later ones had the focuser disconnected from the mirror which was the main issues on these

 

I will be mounting my Moonlite focuser on this too vs stock 

 

thanks I may have looked at the link but will recheck 

Cheers

 

Simon 

[buckeyestargazer]

I spent quite a while collimating my CFF 250 RC to get it dialed in perfectly.  It only took about 15 minutes to get it "good" but then I spent another 2 hours to get it "perfect."  I started with a Takahashi collimating scope during the day, and then just used the DSI collimation guide.  The DSI guide is fantastic.  

[BobT]

I have a 10" AstroTech truss tube RC and the following test equipment:  HG Laser w/circular hologram, HoTech  SCA Crosshair Laser Collimator, HoTech Advanced Laser Collimator, GoldFocus mask, and a Takahashi Collimation scope.

 

I agree with Joel, the Tak scope followed by a star test is the pick of the litter.  If you choose this method, be sure and remove the baffle tube from the scope before collimating, it's easy to do with the 10" truss tube but problematic with the smaller OTA's.  All of the optical train connections in my system are threaded so there is virtually no play between the Tak scope and the focuser, there may be some detrimental effect if you use a slide-in adapter that is non-concentric and/or sloppy.  I've had no direct experience with slide-in adapters so this is total speculation on my part.

 

Enjoy your new scope when you get it, I really like mine (if we ever have clear skies again  ).

[David07]

Interested to discover that TS now sell a 10” RC where the primary mirror and focuser are decoupled:

 

https://www.teleskop...truss-tube.html

 

I would go for this rather than the older model where the focuser is attached to the primary mirror, collimation will be much easier. 

Edited by David07, 30 September 2018 - 11:06 AM.

[geothomas]

Does this mean that the Primary doesn't have to be collimated?  I think I read that it still CAN be collimated, if so, when/why would you if the primary mirror is fixed position?

[BobT]

If I'm not mistaken, all GSO 10" and larger truss-tube RC's have had the decoupled focuser for a couple of years.  I happen to own one of the early models where the focuser is attached to the primary mirror but have not noticed any sagging problem even with a heavy equipment load.

[Richard Whalen]

First make sure everything is square and centered before collimation. My secondary was a hair off center when it arrived.