Focal length problem

[mark RD]

I just bought a Bresser AR127 second hand. And I have a bit of a problem. There is not enough outward travel on the focuser to reach focus on the eye pieces  it come with,  Or my Meade 4000 series.

I have took the lenses out of an old 3X Barlow and used this as a spacer and managed to get it to focus I also had to use a different diagonal as with my spacer the diagonal it come with still will not reach focus..

Surly it did not come out the factory too short or am I missing something obvious?

 

 

[Carbon Brush]

Often refractors require either an extension tube, or a 90 deg adapter to reach focus.

The Bresser refractors usually come with a bundle of bits for this purpose.
Was it bought 2nd hand? The previous owner may have failed to pass them on.

HTH, David.

[jock1958]

Not familiar with the AR 127 but it does sound strange 🤔, only things I can think of has previous owner modified it in some way IE: have they shortened the tube? are the targets you are looking at some distance away IE: celestial or a distant tree?

As far as diagonals go I know my prism diagonal has a shorter light path than my mirrored one.

Maybe some photos and more info might help?

[Carbon Brush]

When I bought my AR102 (shorter FL) used, the seller included everything that had come with the new scope.
This included extension tubes and a diagonal. These were necessary when I first tried it.
A look at a retailer web site will describe what is in the box.

The scope is solely used for solar now so I have almost forgotten about the extensions and diagonal.
The 'too short' tube was very useful to accomodate the 115mm path length of a 2" Herschel wedge.

HTH, David.

[StevieDvd]

In my head I had the AR127L & AR127S models so did a qick google to see if I had that right. In a review for the AR127S there was a mention of getting a focus with a 2" diagonal but not a 1.25"

So I'd agree with the others that either the scope is missing some included 'as new' parts or the tube has been shortened (this is often done to get a working binoviewer setup).

[mark RD]

6 minutes ago, StevieDvd said:

In my head I had the AR127L & AR127S models so did a qick google to see if I had that right. In a review for the AR127S there was a mention of getting a focus with a 2" diagonal but not a 1.25"

So I'd agree with the others that either the scope is missing some included 'as new' parts or the tube has been shortened (this is often done to get a working binoviewer setup).

I did look up the parts that come with the scope and everything does appear to be there. I am using a 1.25 diagonal so that would be where the problem is. Besser do offer extension tubes of diffrents lengths but to be honest I have a small lathe and could knock up the parts for way less money. There was a couple of extra eye pieces included and the previous owner claims he had only used it three times.   It does look in unused condition so I would guess he had the same problem and gave up on it.

[mark RD]

I was intending on buying a decent 2" diagonal anyway so if that will solve the problem then that is great.