Bobs knobs in C11

[Trentend]

New set up for dark sky trips slowly starting to come together (used C11 on AZ100 and planet tripod). The latter arrived today. Bigger than expected but very stable and a doddle to fit the mount on so am glad I went with that rather than the lighter tpod which would have needed counterweights. The AZ100 is a serious bit of kit. Stuck the C11 on it. Rock solid and movement in all directions, once balanced, was sooo smooth. In hindsight didn’t need the tilt handle as easy to move using the grab handle on the C11, but hey ho. 

Observing time next few weeks likely to be limited with poor weather so decided to fit the Bobs Knobs so fully ready to go. Followed the instructions loosening all 3 screws a little to begin with then taking one out and replacing one at a time. Surprised at one point how loose the secondary felt. Hope this was ok and I’ve not cross threaded the new screws!

Have started to search for recommended collimation techniques. So many out there. Is there a general consensus on this (seems to be unfocusing on Polaris and taking it from there until the concentric rings are equal). Not sure if there’s something I can do under cloudy skies in prep? I’m used to a Howie glatter in the dob which takes seconds anytime.

Edited May 17, 2021 by Trentend

[JeremyS]

16 minutes ago, Trentend said:

New set up for dark sky trips slowly starting to come together (used C11 on AZ100 and planet tripod). The latter arrived today. Bigger than expected but very stable and a doddle to fit the mount on so am glad I went with that rather than the lighter tpod which would have needed counterweights. The AZ100 is a serious bit of kit. Stuck the C11 on it. Rock solid and movement in all directions, once balanced, was sooo smooth. In hindsight didn’t need the tilt handle as easy to move using the grab handle on the C11, but hey ho. 

Observing time next few weeks likely to be limited with poor weather so decided to fit the Bobs Knobs so fully ready to go. Followed the instructions loosening all 3 screws a little to begin with then taking and out and replacing one at a time. Surprised at one point how loose the secondary felt. Hope this was ok and I’ve not cross threaded the new screws!

Have started to search for recommended collimation techniques. So many out there. Is there a general consensus on this (seems to be unfocusing on Polaris and taking it from there until the concentric rings are equal). Not sure if there’s something more scientific? I’m used to a Howie glatter in the dob which takes seconds.

Pics please. Not sure I’ve seen a C11 on AZ100 + BB planet. 👍🏻

Are you using counterweight arm and cw, or are you talking about balance in alt only?

[Trentend]

I’ll get some pics on tomorrow. So far am using the alt only. Feels rock steady and hopefully not a tip hazard (famous last words!).

Certainly not a grab and go set up, but the three main components are just about easy enough to break down and carry separately to the car and set up is around 60 seconds only. Certainly think I’ll be more inclined doing that than taking a truss dob apart and back up again which is closer to 10 minutes plus another 5 trying to find dropped wing nuts. Once collimation sorted looking forward to trying the NV goggles in this at a dark site.

Edited May 17, 2021 by Trentend

[Trentend]

The big surprise with the mount is how smooth the slow mo controls are even with a big scope onboard. I have a mak127 on a zero mount for genuine grab and go which is fantastic but didn’t realise how stiff/tight the controls were on that until trying the Rowan this evening. Need to read up on the zero mount forum about loosening that a bit.

[newbie alert]

Not too sure if you're imaging or just visual,  but I just changed my collimation bolts on my c8( not Bob's knobs) and I also used for the first time my tri-mask.. I'm impressed , like really impressed with it..

Since I've taken this pic I've refined the collimation some more

[Mr Spock]

What I used to do with my C925 in the house is look down the eyepiece holder from 2-3m away and make sure all the circles are concentric. Then when I got out to a star test, final adjustments with Bob's Knobs was a doddle. 

When I fitted Bob's Knobs I just took the secondary out to do it. Seemed the easy way.

SCTs are much easier to collimate than people think. Not having to mess with tiny crosshead screws helps!

[garryblueboy]

On 17/05/2021 at 21:23, JeremyS said:

Pics please. Not sure I’ve seen a C11 on AZ100 + BB planet. 👍🏻

Are you using counterweight arm and cw, or are you talking about balance in alt only?

How about. C9.25 Jeremy