Advice on mounting scope on HEQ5 mount

[Dean]

Hi over the summer I reconditioned a telescope my father built 36 years ago and have now been thinking about mounting it on my HEQ5 mount.

The reason for wanting to mount it on my HEQ5 is because it was built for lunar and planetary viewing so it has a long focal length and so I was wonder if I could have a go at some planetary imaging with it.

I am thinking of buying some skywatcher tube rings and dove tail bar and a low profile focuser.

The concerns I have are

Will the mount take the weight of the scope?

The limit of distance between the tube rings because of the truss.

Here are some photos of the scope with measurements.

Any advice would be great.

Thanks Dean

[jgs001]

Dean, I'm afraid that the pics didn't work. Tube rings and dovetails are the best bet, but it sounds like it might be a truss tube of some sort, which may make balance tough. How much does the scope weigh ?

[daz]

Dean

Your image names are both "jpg.gif"......

So, will answer as best as possible....

The HEQ5 will take around 18kg, so if your scope is less than that, then no problem.

However, I'm not sure its a good idea to try and mount a truss tube scope. You'll end up with all sorts of flex issues I would think...

[Dean]

Sorry John picture now attached

[jgs001]

You'll probably get away with it, but might need a long dovetail bar. Daz has a good point though...

[Dean]

Thanks I did not think of flex issues because of the truss design. The build of the scope seems strong but while tracking and imaging under magnification flex issues could show maybe. How would flex issues show themselves?

[haitch]

Thanks I did not think of flex issues because of the truss design. The build of the scope seems strong but while tracking and imaging under magnification flex issues could show maybe. How would flex issues show themselves?

It would probably give a movement in collimation. I reckon the eaiest way to detect that is collimate it with a laser collimator. Leave the collimator in and move the scope up and down and see if the dot moves. If it does then something is flexing (could be anything from the secondary holder/spider to the tube/trusses).

TBH I can't see why is would flex any more than it would in the dob base as you will be supporting it around the tube section I guess rather than clamping the trusses.

Could also be referring to flexing of the whole scope against it's alignment and so not tracking but that's more easily solved I think.

Hope that helps