Building an Alt-Az mount

[michael.h.f.wilkinson]

I am currently building an Alt-Az mount for use with my APM 80mm F/6 for general wide-field and possibly some birding, or my little Lunt, or the 80mm Lunt upgrade once that is done. It should also be able to handle fairly hefty 90 deg binoculars, although I might want to make a full fork in that case. It is attached to my home-brew EQ1 tripod hardwood upgrade. The material is birch plywood. I still have to add some Teflon pads, but it is already quite smooth. I also want to add a locking mechanism for the altitude axis, and of course protect it from the elements with teak oil or something similar. I must say it is holding the APM 80 so steadily I think it could handle much heavier scopes.

[Moonshane]

that's a superb idea Michael. I especially like the cup holders

[swamp thing]

Great concept Michael I've been thinking of a "Dobfractor" myself in the future.

[michael.h.f.wilkinson]

that's a superb idea Michael. I especially like the cup holders

Thanks, I only included 2" cup holders, as the 1.25" are only good for espresso, and I don't drink coffee

[michael.h.f.wilkinson]

Great concept Michael I've been thinking of a "Dobfractor" myself in the future.

Thanks, Steve. I must say I was a bit worried about the thing not being strong enough, so it turned out somewhat over-engineered, but it is still very portable (2.7 kg for the mount, all that wood adds up). I have made the locking mechanism for the altitude axis, using a little strip of Teflon I had lying around, and a screw with a nice knurled knob liberated from my old EQ1 mount. I am getting more Teflon and a sheet of ebony star to complete the job later this week

[Stu]

Looks fabulous Michael.

Question.... How do you cut your circles so cleanly and accurately?

Stu

[michael.h.f.wilkinson]

Looks fabulous Michael.

Question.... How do you cut your circles so cleanly and accurately?

Stu

Thanks Stu. I have a very sturdy hole cutter (these are 10cm diameter (minus the thickness of the blade)).

[nightfisher]

Michael, that is very good, im well impressed

[Stu]

Thanks Michael. Looks very effective!

[Damo636]

Very impressive Michael!

[michael.h.f.wilkinson]

Just had first light with it on the sun. Worked nicely despite the lack of a Teflon disk in the azimuth axis, and an undersized disk in the altitude axis (a 73mm instead of the optimal 98mm).

[michael.h.f.wilkinson]

Just had another, sterner test of the new mount, pushing magnification all the way to 137x with the 80mm on Jupiter. Though the image was small compared to my C8 what struck me was the stability of the new mount, and its ability to damp out vibrations. I estimate the damping time at in the order of 1-2s! Really nice. The only problem was that Jupiter was quickly covered by clouds, so I only got a brief look, but that is hardly a fault of the mount (.... or, is it? )