Hey, hey, hey now. What kind of group is this? There may be children on this list, we shouldn't be talking about our knobs out in the open like this 8^) Next...
3911
cstarsnc
Oct 1, 2002 2:24 pm
Bob, I have built a lot of things, furniture and scope stuff. I stand by my own experience, others' not withstanding. I have found 13-ply, ~3/4 inch, plywood...
3912
Thomas A Simmons
rumybro2
Oct 1, 2002 2:25 pm
Nice article, Bob. As far as the "more plys=stronger" 1) Your truss tubes; are they solid? Where is the strength? Function of outside diameter and wall...
3913
rdeschambault
Oct 1, 2002 2:58 pm
Hi, If anyone is interested, there is a very good supplier of speciality woods, including Baltic Birch. They are called exotic woods and have a website: ...
3914
Mike Warne
mike_warne
Oct 1, 2002 6:09 pm
I'll bet someone could rig up an optical computer mouse and a laptop to track motions in all directions. Probably be able to use something like Mel Bartels...
3915
Frank Bov
frankbov
Oct 2, 2002 2:17 am
FWIW, I've used both Home Depot birch plywood and Russian birch plywood, and I have to say I found the latter to be a far easier product to work. The Home...
3916
Russell Chase
chaseru
Oct 2, 2002 7:28 pm
... Not all multi-ply hardwood core birch plywood is the same. Russian Birch, often referred to as Baltic Birch, is inexpensive but look at the sheets closely....
3917
Chuck Taney
chuckiert
Oct 2, 2002 7:52 pm
Russell, I buy birch plywood at Hoem Depot in 4' x 8' sheets, and I always assumed I was buying Baltic (nee Russian) birch plywood. Your email makes me think...
3918
cstarsnc
Oct 2, 2002 10:57 pm
Russell, My experience is different from your words. The 13-ply Baltic Birch plywood that I get from The Hardwood Store of North Carolina ...
3919
m51john
Oct 3, 2002 2:24 am
Chuck, The Birch plywood they sell at Home Depot is your normal Douglas Fir plywood, but it has a Birch veneer for appearance. Douglas Fir is a softwood and...
3920
Russell Chase
chaseru
Oct 3, 2002 8:35 pm
... badly ... Woodcraft also sells the cheaper Baltic Birch, but I noticed that they use the term "Finnish Birch" to name their better multi-ply hardwood core...
3921
cstarsnc
Oct 3, 2002 11:01 pm
Hi Russell, Thank you for the information and web site. I found out today from The Hardwood Store of NC, that they get their 5x5 sheets of 13-ply Baltic Birch...
3922
William Blakeslee
williebluestar
Oct 3, 2002 11:54 pm
Hi all, A friend asked me something and I was clueless, so I thought I would ask this group. Has anyone heard of using fiber optics instead of using a ...
3923
John Ridley
j_ridley2000
Oct 4, 2002 12:06 am
... Fiber optics are used at the focal point of large reflectors for spectroscopy. I saw a thing on TV the other day where they were setting up to do precision...
3924
colt45hp@...
colt45hp
Oct 4, 2002 12:19 am
I'm going to jump into this with limited knowledge, hoping that other BigDob members can enlighten WB and myself. To duplicate the area fielded by a...
3925
ASmith4062@...
acs1925
Oct 4, 2002 1:38 am
I do not fix things that ain,t broke! Al [Non-text portions of this message have been removed]...
3926
m51john
Oct 4, 2002 4:01 am
I purchased Baltic Birch plywood from The Hardwood Store in San Diego. I used it to build a new base for one of my Dobs. It was the Russian 13 ply,5'X 5'sheet...
3927
Rick Towns
rick@...
Oct 4, 2002 2:16 pm
I'd like some advice on how to proceed. I currently use a modified 10 inch Meade dob, and it works great. However, I just wish it was BIGGER. I'd like to go to...
3928
Ricardo Dunna
rdunna.geo
Oct 4, 2002 2:23 pm
No. You shall put the fibers end at the prime focus, not at secondary position. the diameter os the bundle will determine the visible area field. Ricardo Dunna...
3929
John Ridley
j_ridley2000
Oct 4, 2002 2:42 pm
... That's a great size. I have a 15 truss tube dob and I love it. If I was doing it again I'd probably go to 18". I picked the 15 because the eyepiece is...
3930
Bill Mitchell
astronutski
Oct 4, 2002 2:48 pm
Hi Rick, The obvious answer to me is, BUILD IT! If you need assistance, get Kreige and Berry's book. This way you can spread out the purchase price over a year...
3931
Mike Wirths
mwirths
Oct 4, 2002 2:48 pm
Hi all, I just sold my dual axis platform to a gentleman with a tectron (24 I think). He has his scope on casters so he just rolls his setup out of his garage...
3932
slksc928
Oct 4, 2002 2:55 pm
In addition to the recommendation for Discovery scopes, you could check out the Tele-Kit by AstroSystems (http://www.astrosystems.biz/telekits.htm). Their 16"...
3933
colt45hp@...
colt45hp
Oct 4, 2002 3:05 pm
To John Ridley: The 18" scope has 1.44 times the light grasp of the 15", or 44% more. The 15" scope has 2.25 times the light grasp of the 10", or 125% more. ...
3934
ASmith4062@...
acs1925
Oct 4, 2002 3:21 pm
Hi Rick, I have an 8" newt and also got that dreaded fever. Our club president has a 16" Meade Dob scope, And that was what got me going. The view through that...
3935
ASmith4062@...
acs1925
Oct 4, 2002 3:25 pm
Where would the area of the prime focus be in a Newtonian scope? Al [Non-text portions of this message have been removed]...
3936
Rick Towns
rick@...
Oct 4, 2002 3:41 pm
Well, I was referring to $2500 Canadian, which is about $1700 US. I checked, and a Discovery 15 inch truss is $5000 here, which is way beyond my price budget. ...
3937
John Ridley
j_ridley2000
Oct 4, 2002 3:47 pm
... At the focal point. For a 10" f/5, at 50" from the primary. For the large research instruments that use fiber optics, typically the instruments would be...
3938
John Ridley
j_ridley2000
Oct 4, 2002 3:52 pm
... That makes the budget a lot harder to live with... ... Do yourself a favor and pick up the book _The Dobsonian Telescope_ by Kriege and Berry from Willman...
3939
colt45hp@...
colt45hp
Oct 4, 2002 3:56 pm
Regarding Aperture Fever, here's the mistake I made: About 3 years ago I bought a 16"f/4.5 Meade Dob. It was OK, giving me 2.56 times the light grasp of my...
