Please Help! My knees and neck are killing me!

[MrMiniMoto]

Hi everyone and good morning.

I have what I believe to be quite a unique issue with a recently purchased vixen vc200l. I've done quite a bit of scanning round the net and on here and can't find anything I believe to be related to the issue.

Oh and this thing is second hand, but it does seem to have been well looked after.

I'll be as brief as I can with the description.

Ok so point it at the sky (close to the horizon) and take a look. It's on quite a big mount so putting the eyepiece straight in the scope is not too uncomfortable and all is good with the 3 eyepieces it came with.

Now when I add the angle mirror I can't get focus. It's as if the focus rack isn't moving in far enough. It literally hits the end of its movement before focus is achieved.

Last night I took it to an upstairs window to try and figures out what's going on with it and this is what I found (numbers are estimates)

With the angle mirror attached it achives focus on objects between 15 and 50 meters only

Remove angle mirror and focus can be achieved from 49 meters and beyond

I understand kinda what's going on with the eyepiece becoming too far away from the focal point of the scope but need to know if I can fix it? A stiff neck takes to pleasure out of the viewing quite quickly.

Thank in advance to anyone who can help point me in the right direction

Clear skies!

Chris

[nightfisher]

Hate to say it but with the diagonal fitted sounds like your running out of "out" travel on the focuser, as the vc has arack an pinion i dont see how to solve this

[JamesF]

It seems odd that you should be unable to get enough inwards focus.  Insufficient outwards focus would be easy enough to fix with some sort of extension, but lack of inwards focus suggests that the diagonal perhaps has too long an optical path or that the primary mirror is not in the correct position.  Or perhaps something odd is happening with the corrector lenses.

It's an unusual design and I'm guessing that not an awful lot of people will have owned one.  You might end up having to talk to Vixen or a Vixen dealer about it.

I guess it's worth checking that the focuser fitted is the stock part and that you're not using a 2" diagonal or something like that?

James

[Alien 13]

Hi Chris, if its this one http://www.vixenoptics.com/reflectors/VC200L.htm it looks to be optimised for astrophotography although it does mention an optional extra flip mirror so it should work with that.

Alan

[MrMiniMoto]

Hi and thanks for your quick responses. Your better than vixen, it takes them ages hahaha.

And you give better answers too as all they did was confirm to me there was a problem and this shouldn't happen. They did offer to take it in to have a look but at my cost, they're in the US though so I turned the offer down due to postage costs.

How much adjustment is there in these things?? I have an engineering background and it's telling me to wind all adjustments right in and then re align everything. I figure if the mirrors are a little closer together the focal point will move a little further down the tube??

Or is it the other way round and I should wind them out first?

I'm quite keen to tinker with it but don't want to completely screw it up. And I assume I can't break it by playing with it?

Thanks again

[MrMiniMoto]

Hi Chris, if its this one http://www.vixenoptics.com/reflectors/VC200L.htm it looks to be optimised for astrophotography although it does mention an optional extra flip mirror so it should work with that.

Alan

Hi Alan

Yes it's one of those, it's old but it's the same model number so I assume nothing has changed. It came with various papers and a catalog which had the year 2000 on it so I can only assume it from then. The guy sad it was about 10 years old.

Chris

[Alien 13]

I have no experience with this type of scope but the general rule of thumb with making any adjustments is just a little on each screw in turn.

Alan

[Cornelius Varley]

The very sparse instruction manual suggests that you can place an extension tube between the focuser and flip mirror / diagonal http://www.vixenoptics.com/PDF/VC200L_VMC200L_English.pdf . If the telescope has the extension tube you might not be able to reach focus. A couple of photos of the set up might help us here. 

[JamesF]

I agree.  Some photos would almost certainly help.

James

[MrMiniMoto]

The very sparse instruction manual suggests that you can place an extension tube between the focuser and flip mirror / diagonal http://www.vixenoptics.com/PDF/VC200L_VMC200L_English.pdf . If the telescope has the extension tube you might not be able to reach focus. A couple of photos of the set up might help us here.

Hi Peter.

You know them situations when you've been studying something for ages racking your brain and then someone points out something really obvious? You've just done that to me my friend !! I feel a bit stupid but I'm so happy now!

There was a 2" tube screwed to it. It must have been on there since the day it was bought, I had to use an oil filter wrench to undo it!!

Anyhow, the stupid feeling has already been suppressed by one of excitement because it's going to get dark later.

Massive thanks to all who helped with this!!

Clear skies!!

[JamesF]

Hi Chris, if its this one http://www.vixenoptics.com/reflectors/VC200L.htm it looks to be optimised for astrophotography although it does mention an optional extra flip mirror so it should work with that.

Alan

I did wonder if the "astrophotography" tag meant that it was never intended to achieve focus with a diagonal, but some of the images found by google suggest that it should work.

James

[pete_gamby]

If you need support on Vixen products in the UK (including for second hand equipment) you can find our contact details here - http://www.vixenoptics.co.uk

HTH

Cheers, Pete