Trruss Rod Dobs

[Earl]

Where is the balance point on these.

As im pondering with the right rings these could be GEM EQ mounted, and used for imaging?

Maybe a little work on balancing, but im sure this could work.

[brantuk]

Could be tricky - they normally balance round about where the rods meet the tube - does on mine at least - some dobs have the trusses coming straight off the mirror box way down low.

[Earl]

very true..

i was thinking skywatcher ones not the uber lightweight portable jobbies

[brantuk]

If I was gonna do it I think I'd choose a solid tube 300P - but you need the mother of all mounts lol

[RobH]

Unfortunately, most commercial truss tube dobs, while being rigid enough for visual, aren't rigid enough for imaging.

Shame

Cheers

Rob

[JamesC]

Like brantuk says the balance point is right where they pivot on the dob base. They have circular pods that stick out to meet the dob base - see the images on the opticalvision website. I think you'd be doing well to get a tube ring above the balance point because if you go above where the pods stick out I think you're going to hit the things that hold the bottom of the truss tubes. I could check on mine, but I doubt there's room for a tube ring.

Anyway do you really want to do imaging with a truss tube? I cover the open part of the tube with camping mat and also extend the tube a bit with camping mat to prevent dew on the secondary. I really wonder what all that does in the way of tube currents. Seems to give steady enough views after a cooling period, but I imagine solid tube is better.