Posts Made By: Jim Moscheck

I have an 10" dob.
Definitely not rich, but telescopes may come and go, but good EPs can last a lifetime.

For DSO's I mostly use:
26T5
17T4
12T4

For planetary:
UO18mm ortho
UO12mm ortho
Nagler 3-6mm Zoom
Orion shorty plus barlow

I'm in the planning stages of a dob ATM project and need some advice. I haven't done too much observing with any large dobs, just looks through some friends instruments. I have a XT10 and an LX200 8".

I'm to the point of ordering the primary mirror and here are the choices I've narrowed it down to. I've decided on a Stevens mirror.
14.5" f/4.3 1.6" thickness
16" f/4.5 1.6" "

I'm 5'6" and with the 14.5 I'll probably get away with just a small step stool for the zenith and using my adjustable chair for lower altitudes. I will probably need a ladder with the 16" F/4.5?

My main questions are:

1) With the XT10 as my smaller scope is the 14.5" a big enough jump in aperture?

2) Will I see much difference in the 16" compared to the 14.5"? The 14.5 will be a bit more manageable for one person to transport and I guess a smaller or, no step ladder?

3) With the 1.6" thickness would a 9pt. cell be adequate for the 14.5? I figure the 16 would need the 18pt.

4) Lastly, is a mirror cell fairly easy to make? I'm an experienced woodworker but I have no way to cut metal and would need to hire a metal shop to cut the triangles and bars. I would like to make it myself just because, but if it would be less expensive in the long run I'd rather buy one. Where are good places it but one? Again, any opinions would be welcomed.

Sorry if all this has been covered before. I spent some time searching past posts, but haven't found everything I need after many hours of reading. BTW I'm using Kreig and Berrys book.

I getting excited to begin this project!

I'm ready to order a secondary mirror for my truss tube project and need some advise as to it's size. The primary mirror is a Stevens 14.5" f4.3. My calculations are pointing to about a 2.75", trouble is standard sizes are 2.6 and 3.1". I'm leaning towards the 2.6" after talking with a few people, but wonder if anyone has any thoughts, or, if they might have a similar mirror what size secondary does it have? I'm mostly wondering about the illumination at the edge of my widest field EP, a 26T5. Also, I might someday get a 31T5, but I am satisfied with the 26T5 and it's exit pupil is smaller.
Thanks and clear skies,

Maybe a star party isn't the best way to check out entry level scopes, but check your local astronomy club. My club, as I'm sure many other do, has a monthly beginner's night usually around first quarter moon. It's a chance to get out and talk astronomy with beginners and show them how to use thier new equipment or to show them what we use. With a big bright moon and any visible planets as targets it helps to ease beginners into observing. We have six a year beginning in April and ending in September and even with Michigan's unpredictable weather we usually get in at least three sessions.

I've been ordering parts for my project and have a question about truss tubes. Are these what I want?

https://www.onlinemetals.com/merchant.cfm?pid=7537&step=4

They are milled and are shiny aluminum, but I don't know if that's what I want. They didn't have anodized. Or should I just put foam insulation on the tubes ala' Obsession?
Thanks,

I couldn't agree with you more. I changed my profile about a year ago for this very reason.

For the past year I have been studying Kreige and Berry's Dobsonian book and I'm getting ready to start building my first truss tube dob. The optics are a 14.5" f4.3 primary and a 2.6" secondary. Most of the parts are bought and I just picked up the beautiful European birch plywood last night. 8)

So I haven't even cut any wood yet and I'm starting to get nervous. :S I've been studying the section on balancing the scope. How successful were those of you who have built truss dobs in making a balanced scope on the first try? I'm an pretty good woodworker, but somewhat mathematically challenged. :S

Any advice would be appreciated.

After many months of planning and accumulating many of the parts I've finally started construction of my first truss dob. I made the first cuts of the beautiful 4x8 1/2" european birth plywood and have started the UTA rings. It's going to be a Kriege style with 14.5" F4.3 Ed Stevens primary. 8)

I'm thinking ahead and I have a rocker box question. The book says to make the rocker sides 1" thick. I have both 1/2" and 3/4" plywood. Would making the rocker sides 1 1/4" thick cause any problems other than making it heavier? The book says to make the side bearings 1 1/8" thick.

Thanks,

Just came across these photos and I am just floored.

This first one is what they wanted.

I just saw on Sportscenter what happened last night in the Dodgers/Padres game. Four home runs in a row to tie the game and then a couple more for the walk off win in the tenth. As a long time baseball fan all I can say is WOW!

[SIZE="Large"]Go TIGERS[/SIZE]