Constructing a dob

Yes Matthew, I'm afraid I picked up this terrible condition of aperture fever alright. Building a 16" f/4.5.

Nice, but what I would like to know is how much that 16" mirror will cost and which company would be the best to get it from, for future reference of course .

I'm getting them from Telescope Service in Germany. Primary mirror + secondary + 2" focuser for 1250euro (shipping is only an extra 25euro by DHL courier). That's less than half the price you could get similar optics from anywhere else. They are the exact same optics as in the new Meade 16" Lightbridge. I don't expect them to be amazingly incredible accurate optics, but they are rated as "diffraction limited" and should do just fine for deep sky observing. For the price, they're a real bargin.

Looks like this is coming together well for you Michael, can't wait to see it. :!:

With all the bad weather we have of late, rumour has it that you have 8 spare aluminium poles. I'll take them out of your way for you if you want...

wow mike i think thatts a great price! and i really have to sing the praises of DHL! Ill buy stuff on ebay from 10 germany before the uk because shipping is always a FRACTION of the price!

I'm getting them from Telescope Service in Germany. Primary mirror + secondary + 2" focuser for 1250euro (shipping is only an extra 25euro by DHL courier).

Thanks Michael. I've added them to my favorites. Their prices do look good all right :shock: .

B&Q Swords also had Al tubing of about 27mm od in stock. I think it was in the TV hardware section as an Antenna mounting pole.
Have a look!

Another option would be to try angle Al, again from B&Q. Mount two pieces back to back so that you form a 'T' section with the horizontal nearly twice the length of the vertical, use an adhesive to stick the two vertical faces to each other. With a solid adhesive ie some thing like super glue rather than a flexible glue like a Bostic you may get enough stiffness- need to experiment first!

Well folks, mirrors arrived today:

www.astroshot.com/Dob/1.jpg

Primary mirror:
Diameter = 405mm
Thickness = 40mm
Weight = 12.2kg

Secondary mirror:
Minor axis 88mm
Thickness = 18mm
Weight = 403gr

2" Focuser:
Weight = 650gr
Travel = 35mm
Comes with 1.25" adapter