FIRST LIGHT: Skyliner Flextube 350p

[astronymonkey]

Great to see you got some first light on the scope despite the less than perfect skies. Im sure you have come away with loads of ideas of what you need to tweak to make it perfect which is where the fun begins.

Im wondering if the focus issue could be anything to do with the way in which you fitted the mirrir. In your unboxing review you said

"I noticed that the lock bolts are completely useless. I tightened the mirror/spring bolts up as tight as they could go and the lock bolts dont even touch the cell at all. They are literally useless, they should have been 5-8mm longer. I've left them in for now but the mirror is sitting on the spring bolts only which means it's not going to hold collimation at all. I'm going to need to think about this. Have I put it together correctly? This was done without instructions again and this seemed like the only sensible configuration - if the springs were not where I put them then the mirror would be sitting on OTA cell directly with no cushion."

Im wondering if this suggests the cell collimation screws may in fact be tightened up in a way that the mirror is as far up the tube as it will go, which is suggested by the fact the lock bolts dont reach the cell. This would increase the amount of back focus needed and might explain the focussing problem you had.

Clear skies

[Stargazer_00]

That was the same thought that occured to me too. I'm going to take the collimation bolts and screws off again and see if it can be assembled differently.

[astronymonkey]

This gives some good closeups of the cell on a 400 flex which will give an idea of what it should look like on a 350 aswell. http://scopeviews.co.uk/SW400P.htm

Ive also searched SGL and there is a post by Albireo380 who had the same problem http://stargazerslounge.com/topic/78335-flextube-350-mirror-cell-help/ . They were last active on 13th June so it might be worth a PM to see how it was resolved.

Cheers

[Matt Scunthorpe]

Many thanks for writing this.

Good to hear that it is a good peice of kit. I still contemplate getting one for when i dont want to do AP and can't be bothered to set up all the tripod, mount etc.

[mert]

Good luck, what a lovely scope, still too light here to do any sort of viewing at nights.

[faulksy]

Good luck, what a lovely scope, still too light here to do any sort of viewing at nights.

I love loch Rannoch, beautiful place, nice going with the scope graham the others look tiny

[Stargazer_00]

Looked at the mirror again today and I had definitely done it right the first time. The springs seems to have settled somewhat since taking the mirror's weight and I managed to get a full turn more out of the collimation bolts. The locking bolts now do contact the cell (but seriously only just) and the collimation bolts have about half a turn till they are physically maximum tightness. So all is well

Need some nice dark early skies to come along so I suspect the scope is just going to be collimated over and over for a few months until the skies come back to us.

[John]

....I was thinking this too. The focuser is closer to the top lip than the other two scopes. I'll see how it performs in practice. I have an astrozap coat for the central part on it's way as there is no way I'm going to expect serious views from it in a light pollution area without a coat. I'll have a good think about how I can make a half tube baffle for the opposite side of the focuser.....

My secondary is quite close to the top of the scope tube as well so I use an AE partial light shield opposite the focuser as shown below. I have quite a lot of stray light where I observe (back garden !) and this helps keep it away from the secondary and the end of the focuser drawtube. Its surprising how much contrast you can loose on both DSO's and planets from too much light around the top of the tube.

[Rustysplit]

Like John, my focusser/secondary is also close to the top. I use a simple part sheild that looks just like John's, but simply made from 2mm fab foam from hobbycraft, held in with a couple of squares of velcro. Makes a huge difference if there is any stray light around.

[Stargazer_00]

Thanks guys. I have been wondering how to tackle that problem. Velcro and Fab foam sounds like a winning solution. I want something that is easily removable as a permanent fixture would prevent the shower cap/bag thing that was provided with the scope from being fitted. The flex tube secondary cage 'cover' is a bit rubbish in my opinion. I'd sooner have seen another plastic cap like the tubes usually have for this part. I will have an astrozap coat on the flex tube part (which can be left on permanently) so that should stop dust and other particles getting onto the secondary from below.

[faulksy]

hi graham, you should be able to get out tonight skys are turning lovely and blue here and the west horizon is blue as well, hope to try out my new 18mm bgo tonight as it only came this morning

[vlebo]

Astrozap make one for the 14"

http://www.scopestuff.com/ss_azs1.htm

[mert]

I love loch Rannoch, beautiful place, nice going with the scope graham the others look tiny

If you are up this way in the future give me a shout.

[petek314]

Graham, I have the 300p Goto truss mounted scope. When you mentioned you had trouble focussing it reminded me of something I found odd. When I slide out the truss on mine I reach a point where the mount clicks. At this point it is not at its fullest extension so I pull it out further and then set the lock screws. At this distance it seems to focus ok. I find it puzzling that the scope has the click point a few centimetres before its fullest extension. Do you use this click point or do you extend the truss to its maximum? Thanks Pete

[Stargazer_00]

I use the click point so I'll check that Cheers Pete

[Dunkster]

Wow Graham, what a cracker! Really gives a sense of scale Look forward to your follow-on with darker skies

[Qualia]

Cracking report, Stargazer and thank you for taking the time to write it up. I'm sorry I came to this late but the past month as been a bit hectic and I just haven't been around.

There are so many things you will be able to do with this scope, so many things to see anew, it will be like starting out all over again. Although the summer months really do have some spell-binding objects (should check out scorpius and sagittarius as Steve suggests), you've also got the long winter nights stretching out in front of you. So much to look forward to, so much to do; what a great time to get your new scope.

[Stargazer_00]

Thanks mate got a astrozap light shroud on it now so will help tonight. Some high level cloud forming right now though. Hope it passes

[Stargazer_00]

It didn't.

[faulksy]

it was the same here last night, but come around 2 it cleared

[paulastro]

Ade Ashford told me that when he was at Mt John in New Zealand they used a goto version of this scope for public outreach. Ade said it had very good optics and operated flawlessly all the time he was there. It was their main outreach scope so it had a lot of use.