Tuesday, July 06, 2010

Poor Man's Vixen Great Polaris

In keeping with my "poor man" theme, I purchased a Vixen Great Polaris mount (without motors) for US $200 on ebay. This is a very low price for a GP mount; my Vixen Polaris is far too small to carry the Celestron C9.25 Schmidt-Cassegrain, so I needed something larger but didn't want to spend much money.

The GP I got (Orion-branded at that!) was cheap for a reason - it seemed to have been stored in somebody's garage for years. All the fasteners were frozen or rusted, and the polar scope was full of dirt. The worm gears were fine though, to my great surprise and delight.

I spent the past three weeks cleaning out the mount (still some rusty screws but those are just cosmetic), re-lubing it, and constructing another of my plywood half-pier specials.







My C9.25 (another ebay special) came with a Losmandy-style dovetail, and I didn't have a Vixen dovetail. The local astronomy dealer here in Singapore doesn't have a 17" Vixen dovetail either, so I'd have to order it again from the US and suffer another long wait.

Instead, I decided to make my own Vixen dovetail.





It's basically three strips of plywood epoxied together for strength (the laminated strips are stronger than a single plank of wood; besides I still had a lot of plywood left over from my latest dobsonian build). I screwed two stainless steel reinforcing straps from Daiso to each side of the plywood, where the Vixen saddle and retaining bolt hold on.

Primitive, but it works.. after a fashion.

Now this mount doesn't have any motors, and to go after Jupiter I need tracking. The Orion EQ-1M is on the Polaris (my grab-and-go, I just realized how much lighter it is after manhandling the Great Polaris plus C9.25 around) and I have some Meade motors lying around. I'll have to fabricate some brackets for the Meade motors sometime.

No comments: