29058Re: Best Drive System For Dob
- Jul 1, 2004Ron,
Thank you for your thoughtful reply. I am new to the group and
did not expect to hear from you. Your book is what changed my
curiosity in CCD work into ambition.
I had a feeling that the dual axis equatorial platform would be
the way to go. Some of the other posts here offer ways to do that
with cost in mind.
As for the truss, I am trying to navigate the trade-offs between
stiffness and wind resistance. I am concerned that an 8 pole truss
system will catch too much wind, defeating the goal of stability. I
am considering using two oversized truss poles with cross supports.
Thank you again for your post.
--- In email@example.com, "Wodaski Yahoo" <yahoo@n...>
> It is easier to build a robust, accurate, and precise equatorialplatform
> than it is to do the same with an instrument rotator. Some reasons:go that
> * You can't just build an instrument rotator to high quality if you
> route; you still need a high-quality drive and tracking mechanismanyway to
> smooth out the bumps. So you really have to build two high-qualitytracking in
> high-precision systems if you go this route. And you are also
> two axes at all times.platforms
> * There are a number of off-the-shelf aluminum equatorial tracking
> for Dobs that will track very well for imaging. And if you build itplatform
> yourself, you only have to make one precision system. And an EQ
> tracks in only one axis.support the
> For either case, you are going to need a stiff truss system to
> secondary cage and the CCD camera. It needs to be stiffer than ifit were
> just for visual use both to maintain collimation as you slew, andto reduce
> vibration during imaging.system, but
> This is not to say that you couldn't do a nice derotator-based
> it will be harder to pull off well.
> Ron Wodaski
> The New CCD Astronomy
> -----Original Message-----
> From: David [mailto:dwasch@c...]
> Sent: Wednesday, June 30, 2004 5:08 PM
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