Spider modification

[wookie1965]

Is there any way of changing or modifying the usual 4 vane spider into a single vane as I have been told can get much better views. 

[Uplooker]

Better views in what way? Do you mean without diffraction spikes? You could achieve this with curved vanes or 2 off circles acting as the vane. I am sure John has a scope using this idea.

[John]

I think "much better" is too much to expect. By changing to curved secondary support vanes you can remove diffraction spikes but you still get diffraction - it is spread evenly over the field of view.

The change needs to be done with some care though because the secodary mirror must be held firmly in place by the new arrangement and the shape of the curved vanes is important. There is a USA company called Destiny that makes replacement secondary vanes:

http://www.1800destiny.com/

The alternative is a DIY approach but, as said, that does need to be done with care. There has been a recent thread on this, here:

https://stargazerslounge.com/topic/291471-curved-spider-vane/

It would be worth waiting to hear what JemC thinks of the results of the change

[Stu]

52 minutes ago, wookie1965 said:

Is there any way of changing or modifying the usual 4 vane spider into a single vane as I have been told can get much better views. 

You won't get 'much better' views, you will get views without diffraction spikes but with the diffraction effects smeared across the rest of the image. The overall effect may well appear more pleasing and it can help avoid faint secondary double stars being hidden in a diffraction spike.

The best option is the one with shortest length of vane which would be a 180 degree arc, but full circles or double full circles work well too.

[wookie1965]

1 minute ago, Stu said:

You won't get 'much better' views, you will get views without diffraction spikes but with the diffraction effects smeared across the rest of the image. The overall effect may well appear more pleasing and it can help avoid faint secondary double stars being hidden in a diffraction spike.

The best option is the one with shortest length of vane which would be a 180 degree arc, but full circles or double full circles work well too.

Where can I get these from please. I`m using it more for clusters and double stars these days because of light pollution so anything that will help focus more on the stars and see them clearly.

Paul

[John]

25 minutes ago, wookie1965 said:

Where can I get these from please. I`m using it more for clusters and double stars these days because of light pollution so anything that will help focus more on the stars and see them clearly.

Paul

There is no supplier in the UK that I am aware of. You may need to consider a DIY approach to this change. The UK based dobsonian scope maker David Lukehurst fits single curve supprt vanes in many of his scopes but he makes those himself:

http://www.dobsonians.co.uk/12f6.html

 

[wookie1965]

That would be Ideal I wonder if he would consider making one for me I can only ask, Cheers for that much appreciated.

[Stu]

I wonder if Mr Drew might be able to assist?