Re: ATM Newbie question on 8" f8

[Barry Keeney <barryk@chaoscon.com>]

    I finished my first scope in november and it was a 8".
it's a open truse design made from steal. it's kind heavy 
when it's all put together but each piece is light and 
it easily fits in a car trunk. the guy who helped me make
mine has a 12.5" version that fits in early 70's toyota 
car trunk with plenty of room to spare.

    the weight makes it easier to use ot me, wind doesn't effect
as much.

    I do suggest you work with someone who's made mirrors before.
I found this made it easier, plus you have some one to talk to
while you push glass...

   here's some pic's of mine:

http://www.swcp.com/~barryk/telescope/

   hope this gives you some ideas.

Barry Keeney
Chaos Consulting
email barryk@chaoscon.com

"Rap is Square Dancing gone terribly, terribly Wrong...."


On Wed, 14 Mar 2001, Brian Lloyd-Newberry wrote:

> 
> Hello all,
> 
>    I have for some time wanted to build a scope from scratch (no pun
> intended...), and have been lurking here for awhile and even asked a
> question about hand pain and TM many months ago. I have decided to leap
> off the bridge and have bought pretty much all of the TM books that
> willbell had (much to the wife's dismay).
> 
>    In the months to come I am planning on picking up a blank and the
> necessary materials. I am leaning toward an 8" mirror and I know that
> the "rule" has been 6" f8 or 8" f6 for the first mirror. Having used an
> 8" f6 that a friend of mine owns I have determined that I do not want
> to be kneeling that much and I am thinking that an 8" f8 would be
> better for those of us who sit for a living and want to stand upright
> on our free time. ;)
> 
>    I am thinking that the eyepiece would end up a little less than 5
> feet from the mirror (in a newtonian config) which when I put the dob
> base on would probably bring it right up to my eye level (5'6" at the
> eyes) at the zenith. My wife might need a "step" to use it at the
> zenith, but that would beat kneeling on the cold and usually wet
> ground.
> 
>    Anything I should know about an f8 vs an f6? There will be less
> glass to move and it should grind a little faster, no? The tube will
> obvoiusly be longer (that is the point) but I figure that if
> I build a simple box tube and split it in the middle I can still fit
> the pieces in the trunk of my Honda Civic without trouble, and with the
> box design they won't roll around.
> 
>    Another issue is that I am planning on using BVC for the primary
> because it is slightly cheaper (and my wife is already going to kill
> me). Is there anything that I should know about BVC vs. Pyrex/Plate? I
> am guessing that I can use the same process as Textereau outlines with
> possibly more precaution against scratching because the BVC is a little
> softer.
> 
>    Thanks for the invaluable information that you all share. I am sure
> that I am soon to be using it more directly. :)
> 
> -Brian
> 
> Brian S. Lloyd-Newberry
> newbeb@yahoo.com
> 
> 
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> 

Barry Keeney
Chaos Consulting
email barryk@chaoscon.com

"Rap is Square Dancing gone terribly, terribly Wrong...."