[Ian Robinson]

Thanks Mick and Gary,

What's the best way of reinforcing an aluminium tube :
at the ends (to protect from dings when moving it about off the GEM) ?
is a strip of aluminium sheet the same thickness as the tube under compression on the inside sufficient
under the focusor tube plate ?
see above
at the spider legs ?
see above
at the cell mounting location ?
see above
at the ring clamp locations (note the rings will move up and down depending on whether I'm imaging or just viewing) ?

See attachment for proposed structure of structural strengthening rings , these look suitable ?

Any chance Anthony Wesley from Murrumbateman might chime in ? - I hear he's done several aluminium tubed scopes .

Images of who others have solved thes reinforcement issues would be appreciated .... a picture is worth a 1000 words.

I guess easiest way to make reinforcing rings is to have the sheet metal company roll a tube for me that's a bit longer than I need , and to ask them to cut some rings off the end ( or if they charge too much , use the mighty Dremel and the mini cutting disk to do the deed ) and then take a bit out (enough to allow the compressed ring to be slid/ pushed into the tube0 , the compression of the ring trying to spring back will give a bit of extra reinforcement , because the spring force will be acting outwards).

Looks like I might need to buy a Demel circle cutting jig for my Dremel to make fabrication of the annular ribs easier than using my big electric jig saw.