As I see it you can take several pieces of wood that you are going to use for the trunions, glue them to gether to increase the thickness, adjust the table saw blade and cut at an angle to this such that the resulting curve will fit the OD if your fiberglass tube. Now you can screw, with washers distributing the load, theough the tube into the trunions. Oh, you can epoxy the trunions to the tube too.
Second alternative _IS_ to use the box design and inside the box glue sections of a rug so that when you insert the tube there is enough friction to hold the tube, balance it and allow you to rotate the eyepiece to a convenient position. I saw this done on a beautiful strip-planked (maple and mahogony) wooden scope at Riverside.
Bob
):-{])) <---- madden@netcom.com madden@svpal.org Remember amateur astronomers: "keep looking for the next Universe"
On Mon, 8 May 1995, David Boll wrote:
>
> First, thanks for the helpful responses to my 'fiberglass tubes' post.
> This mail list is amazing!
>
> Now, I'm hoping to make the fiberglass tube for a 10" f/6 dob scope, and
> I'm considering how to put the altitude bearings on the tube when I'm done.
>
> I don't really care for the idea of building a box around the tube - I know
> it's the traditional way, but I think the scope looks better without
> the box. But, without the box, it is difficult to attach a disk to a
> cylinder - esp. since the tube will be fiberglass, and evidentally
> crushing it between a bolt and nut is of some concern.
>
> So - is there any way I can incorporate a flat spot into the mould to
> make it easier to attach the altitude bearings later? Perhaps I could even
> sandwich a small disk of plywood between the 2 layers of fiberglass, and
> then cut small circular holes in the fiberglass so I could bolt directly
> to the wood? Or, perhaps there's a better way?
>
> Thanks!
>
> -Dave
>
>