Newtonian Aluminium open structure

[GigiG]

Hi all, I've just finished building my newtonian 'light' structure and I'm rather satisfied. The overall structure is rather light (2.5Kg without mirrors) and stiff. The original project was to design a structure different from the usual rigid tube for my first 6" mirror (second hand on italian Astrosell online market). At the mean time, this 'main beam' layout give me the opportunity to evaluate an alternative focus mechanism (of course I was inspired by already existing designs seen on the web in the past). A longitudinal focusing rail to replace the classic radial focuser. The focus is adjusted by translating a 'dolly' that carries the secondary mirror and the eyepiece/camera turret, by means of a threaded rod. Rigid Teflon like plates are used to minimize friction on the translating surfaces. Comments and suggestions are welcome.

Ciao!

Gigi

[Martin Meredith]

Nice work -- very neat. What were the dimensions of the main beam (particularly wall thickness)?

Martin

[GigiG]

The main beam is composed of two 30x15mm aluminium section profile (1mm thick), fixed togheter side by side and about 700mm long.

G

[michael.h.f.wilkinson]

Interesting design. No immediate suggestions, but I am looking forward to a report of the scope in action

[NGC 1502]

Nice one......  ......lots of work, well done.........reminds me of this -

http://www.garyseronik.com/?q=node/189

Hope you can let us know how it performs.

Regards, Ed.

[Dude_with_the_tube]

very interesting concept of newtonian.not that you see these very often.Will be interested to read up how it performs.

Clear skies!

[ollypenrice]

Lovely ideas here. Will the secondary support be adequate, do you think?

Olly

[GigiG]

The secondary support bracket is very robust. It is based on an alluminium strip 1mm thick (25mm wide) curved by hand and it is stiff, more than enough . I can adjust the position of the secondary mirror holder moving its curved bracket with respect to the turret assembly and eventually increasing/decresing its height slightly modifing the curvature of the bracket itself (didn't need to do, however). Not yet tested 'on field' but the collimation was relatively simple (my 6" is an f5).

Thanks to all for comments!

Gigi