Bino-Scope Altitude Drive
(It Actually
Works!)
Since we last spoke, I’ve
completed the altitude drive, painted it, added some fans, and have been having
a blast using the scope. Here’s a
picture of the Bino-Scope’s current
state. (if you can’t see the pictures,
click here to browse the directory there in!)
(Picture courtesy Herb
Markovitz)
Now,
Lets move onto how I put the Altitude drive together. The first thing I had to do was add roller bearings to replace
the previous Dob style Teflon bearings.
Not wanting to rebuild everything, I simply unscrewed the existing Dob
style altitude bearings from the Altitude box,
Drilled a 5/16 hole thru it, then added bearings. Unfortunately the first try failed, as the
wood disk I used for the original altitude bearing was only ¾” thick, and with
two roller blade bearing on each side, it wobbled about its axis. To solve this problem I added two layers of
½ material to the outside of the wood disk.
I placed a bearing on one side of the disk, and on the other side of the
additional support, in effect making the altitude bearing 1.75” thick. The finished bearing looked like this once
bolted to the altitude rocker box.
In the above image, the altitude box is resting on the ground and this is the un-driven altitude bearing. I may be odd, but I find it very enjoyable to reach out and Spin the heck out of that wood altitude bearing, with no resistance it spins for a rather long time :)
Another image of the same bearing from a different
perspective:
At this point in construction I had an altitude box support by a 5/16” threaded rod that went thru the Roller Blade Bearing enhanced original Dob bearings. So far so good. The next bit of fun was adding the wood ring gear, which I did by attaching the gear to the 5/16” threaded rod going from the Altitude box, thru the altitude bearing and ending with the ring gear. Again, the first try failed, as when torque was applied to the gear, it flexed on the threaded rod, which caused a lot of slop and oscillations in the altitude drive. To resolve this I added a wood brace that spanned from the altitude box, over the altitude bearing, and screwed to the ring gear. The finished assembly looks like this:
Item #1 is the additional bracing I added
Item #2 is the free spinning Altitude Bearing
Item #3 Is the wood ring gear
OK, now were making some progress! All that’s left is to attach the Alt Motor to the Azimuth rocker box, wire it and were good to go! Here’s a picture of the Azimuth rocker box with Altitude motor attached.
Item #1 is the PS2 style handpad connection
Item #2 The shiny thing is the Altitude drive pivot
Item #3 is the original Teflon Altitude bearing
Item #4 is the 25 pin connector going to the drive electronics
(This connection is done with an 8’ printer extension cable)
Another image of the Altitude Drive motor:
And
the whole thing put together:
Well that’s it for the
altitude drive, its been working well since August of 2001. While not perfect, it works fine for visual
use. Keeping planets in the Field of
view for hours at a time! I’m VERY
happy with it!
Take
Care,
James
Lerch
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