If you feel inclined, a written up how-to would make a great addition to the site, because I know there'd be a lot of interest from others in making one of their own.
For those that may be interested, this is really going to show my age.
In 1980, yea 1980, i was just starting Astronomy, there were not many mags around on the subject, an hell, there were no computers either to the general public.
Anyway, I used to get the American Sky and Telescope Mag delivered to my door, and on page 333, October edition there it was (Some Experiments With Curved Bolt Drives), well i thought, I can do that, and did, I still use the one I built in 1982, ready for halleys Comet.
This is how it goes...
Firstly the Formula (R=1,436.5x(n/2nt)
This is where (n) is the turning rate of the drive nut in revolutions per minute and (t) is the pitch of the curved bolt in threads per inch.
For my assembly i used a (one reviluntary per minute motor, and a 3/16th curved bolt, which had to be exactaly 9.5200 inch's from the center of the polar shaft.
With some minor adjustments it came pretty close, and truly, i still use my old drive as we speak.
The actual construstion is really to the individual, it can be as elaberat as you like as long as you keep the formula spot on.
By this i mean, if you use a larger thread pitch, you arch will be larger.
I will try to attach some photo's of the drive, please feel free to talk to me.
I would just like to show you how i find the south pole.
I'm pretty lucky actually because the house across the road with that big antanna servrs me just right.
for this shot to find true south i used a cardbord parcel post cannister, which fitted nicely around my Olympus OM 2 Lens, stuck it to the polar shaft with some wire, exposed for half houre with UHF filter and there it is, pretty clos i reckon.
Leon
Not only does your rig display incredible craftsmanship, looks highly functional and appears well designed, it would also look stunning in the garden as a piece of astro-sculpture!
I agree that is an awesome piece of highly functional art Leon, reminds me of when my mate made his own harmonograph - looked a little similiar a bit hehe
also really love the Halley's shots.
amazing how many awesome aussie shots of these famous events are being uncovered and seeing the light of day once again thanks to this forum and its members - onya Mike, Mojo and all
cheers
I will do a how to make this unit soon, unfortunatly at the moment there are two sickies in the family and one is in hospital, so iv'e been a bit busy with the caring stuff.
Leon
![[1ponders]'s Avatar](../vbiis/customavatars/avatar45_9.gif){kind=avatar}
