The tube looks as though it will finish looking nice made out of solid planks. My only question is, how much does it weigh? Or are you going to sand it very thin?
The tube looks as though it will finish looking nice made out of solid planks. My only question is, how much does it weigh? Or are you going to sand it very thin?
Working on the OTA gluing baffles inside the wooden tube. What I have read this helps with contrast of an image, similar to internal light baffling seen in a camera lens. Made from balsa wood. Another eight more ribs to go.
If those octagonal shapes become the aperture stop your stars will have 8 horrible spikes radiating from them, and images of jupiter/saturn will be rather awful.
To be effective the baffles must create a circular aperture - not octagonal.
Best way to do that is to make the baffles out of something thin - 1mm aircraft ply for example, with the hole accurately cut using router with a jig or template to make a smooth perfect circle. Then glue these against those octagonal balsa strips.
The other thing is several 1-piece baffles from material like aircraft ply will substantially strength your tube - looking at it, it appears (a) quite heavy and (b) any localised stress such as where it attached to the mount is likely to break the glued joints.
Traditionally baffle placement is determined by calculation or by ray tracing. I am not wishing to dent your enthusiasm. As far as shape is concerned, yes a circular baffle is desirable. I have used neoprene as baffles on some of my scopes, it is easily cut to shape and can be glued in place, with enough stiffness to hold its shape, and it is already black.
Give some thought to weight, 10kg is pretty heavy for just a bare tube. Have a look at the plywood tubes that Plyscope has built (attached below), similiar to yours but much thinner and probably stronger due to cross laminations of the plywood. Of course that tube is for a refractor but note the baffles are circular on the inside.
If those octagonal shapes become the aperture stop your stars will have 8 horrible spikes radiating from them, and images of jupiter/saturn will be rather awful.
To be effective the baffles must create a circular aperture - not octagonal.
Best way to do that is to make the baffles out of something thin - 1mm aircraft ply for example, with the hole accurately cut using router with a jig or template to make a smooth perfect circle. Then glue these against those octagonal balsa strips.
The other thing is several 1-piece baffles from material like aircraft ply will substantially strength your tube - looking at it, it appears (a) quite heavy and (b) any localised stress such as where it attached to the mount is likely to break the glued joints.
