Posts Made By: Bill Byrd

August 16, 2005 03:08 AM Forum: Equipment Talk

Favorite RFTs?

Posted By Bill Byrd

[COLOR="Purple"]I love wide-field viewing! In light of the discussion about the definition of RFT, how about some discussion of your favorite RFT.

At various times I've used: an 80mm short tube refractor, a 4.25" f/4 reflector, a 5" f/5 refractor, a 6" f/4 reflector, an 8" f/4.5 reflector and a 10" f/4 reflector. Not to mention various binocs from 7X50 up to 16X80. All have their advantages and trade offs as far as light gathering and portability are concerned.

My current favorite RFT is an 8" f/4 Meade SN used with a Paracorr and a 26mm Nagler giving 36X, with a 5.7mm exit pupil, a true field of 2.3 degrees and stars sharp to the edge of the field. Views of the MW are awesome!

My second favorite RFT is the 5" f/5 which gives 24X, a 5.2mm exit pupil and a 3.4 degree true field of view.

Both of these scopes are used in addition to my main scope when I'm fortunate enough to be able to travel to really dark skies.

Sooooo....what scope do you like for richest-field viewing, and why? Inquiring minds want to know! 8)
Bill in SA[/COLOR]

August 17, 2005 01:07 AM Forum: Pictures of Me and My Telescope and........

Re: Ugliest Scope Contest!

Posted By Bill Byrd

[COLOR="Purple"]Okay, it's just the first light where I was fine tuning the secondary location, but it isa scope...sort of.
Bill in SA[/COLOR]

August 21, 2005 07:29 PM Forum: Telescope Making

Cellular Cell

Posted By Bill Byrd

[COLOR="Purple"]Finally getting started on the OTA for the cellular mirror. I'm going to try the "dirt simple" approach for the cell to support the plate and post mirror. If "dirt simple" doesn't work, then I'll have to go to plan "B" and make a more traditional mirror cell.

This overall shot shows the support board for the mirror to sit on. There will be bubble wrap between the mirror bottom plate and the board to give the mirror a nice, cushy surface to sit on. The center plastic piece serves to hold the mirror centered via a hole in the back plate of the mirror. I'll also blow air from a fan through this hole to cool the back side of the front plate of the mirror. The edge clips are to hold the mirror back plate gently against the bubble wrap as the altitude changes.

That's a 1' ruler in the pic...the mirror is 18.75" wide.
Bill[/COLOR]

August 22, 2005 02:39 AM Forum: Telescope Making

Alt Bearing Size?

Posted By Bill Byrd

[COLOR="Purple"]I seem to recall a formula for what size alt bearings should be. Something like 1.3 X mirror size. Anyone have that info or know where I might find something along those lines?
Thanks!
Bill[/COLOR]

August 25, 2005 02:44 AM Forum: Telescope Making

Source For GOOD 4.25" Primaries?

Posted By Bill Byrd

[COLOR="Purple"]Like I need another scope...or another ATM project... wink
I found a very nice tube, sized just right for making a 4.25" RFT. Soooo.....I'm thinking of making a large finder/small RFT that can be used on a scope I'm building.

Anyone know of a source for good quality 4.25" mirrors in the f/4 or f/4.5 range?
Thanks!
Bill[/COLOR]

August 27, 2005 11:43 PM Forum: Eyepieces

Good 1.25 22-24mm With 65+ Degree AFOV?

Posted By Bill Byrd

[COLOR="Purple"]Looks like I'll be needing an EP for a little RFT. I want something with decent eye relief, at least a 65 degree AFOV, not too heavy and good edge of field correction. Hmmm...I wonder if Marcus still has that Pretoria??

All of my current low power EPs are 2" so I'm curious what might be good in a 1.25" barrel. A 22mm Pan might work but would put a lot of weight hanging out from the focuser. The 24mm Pan is too expensive. Is there something in 1.25" that you all have some experience with that might be better?
Thanks for any and all suggestions!!
Bill[/COLOR]

August 28, 2005 07:54 PM Forum: Insects - Flowers and Other Small Stuff - Photos

New Flowers

Posted By Bill Byrd

[COLOR="Purple"]We planted some new flowers yesterday. I liked these.
Bill[/COLOR]

August 31, 2005 12:00 AM Forum: Equipment Talk

Stellarvue F50 Finder Thoughts?

Posted By Bill Byrd

[COLOR="Purple"]I'm considering a new finder and need something around 50mm to keep the weight down. Anyone have any thoughts on the Stellarvue F50? Seems nice but I thought I'd see if anyone here has actually used one.
Thanks!
Bill[/COLOR]

September 5, 2005 08:36 PM Forum: Telescope Making

Mirror Box + Cell for Cellular Mirror - Pics

Posted By Bill Byrd

[COLOR="Purple"]Well, the 3 day weekend allowed me some time to work on the rest of the cell and mirror box for my 18.75" cellular mirror scope project. I built in a fan to blow through the hole in the back plate of the mirror. It will blow on the back of mirror front plate and should cool the mirror very quickly since the front plate is only 5/8" thick. I've been told that even without a fan, the mirror should be getting close to ambient after only 30 minutes. My mirror box is kinda tight to keep the size manageable so some active cooling will be good.

This pic shows the front of the mirror cell with the centering plug sticking up through the plywood.
Bill[/COLOR]

September 8, 2005 02:46 AM Forum: Telescope Making

Extending Aluminum Tubing?

Posted By Bill Byrd

[COLOR="Purple"]I'm hoping the pic attached will help get this idea across. I'm going to need truss poles about 7' long for the scope I'm building; 18.75" f/5.2. A few years ago I bought some poles for a good price. The problem is that they are only about 4.5' long. In the picture you can see that I have some thin wall tube that fits very snuggly into the 4.5' tubes I have.

My question is: Can I get away with using the inner tube as a splice to butt pieces of the larger tube together? Gap filling super glue or epoxy would probably make this a very strong connection between the three pieces.

If that isn't feasible, I'll probably have to get 12' pieces from Texas Towers and cut off 5'. Not a good alternative considering cost and shipping for 12' Al tubes.

Has anybody ever done something like this?

What about making these into two-piece poles? Use string to add tension between the mirror box and upper ring to keep things together...sort of a string scope but not really. That would allow me to have truss poles about 3.5' long, which would be nice.
Any thoughts?
Bill[/COLOR]