My homemade telescope...

SteamWake · 10-26-09, 09:46 AM

As promised in another thread here are some shots of my home made telescope.

I had to tear her down to get ready for winter and blow out a few cobwebs and such.

Only the optics and finders were 'purchased'.

It is a 6" f8 newtonian (dobson) reflector.

These pictures are a little out of order but its un-important.

Front looking down

Side view showing the altitude bearings. The round things. It 'glides' on teflon pads which are just visible. The entire base rotates for azimuth adjustments. Your typical dobsonian mount.

This is the main mirror and mirror cell resting on the table after cleaning.

Another mirror shot this is a vain attempt to show its scale... its 6"

Here is a shot of the diagonal mirror holder aka the spider. The diagonal mirror is allegedly optical 'flat' and re-directes the foucus 90 degrees and up the focuser.

A peek down the focuser 1.25" ... cobwebs.. yuk.

An overall view of the 'tube' its really a box but we still call it a tube

This is the ass end of the scope tube showing the collumnation screws. The three screws are adjusted to align the tilt of the main mirror.

Here the mirror cell is in place but left loose to show the adjustment screws. A funny side note the screws but up to pennies glued to the mirror cell to keep the screws from digging into the wood.

Outside view of the collumnating screws. The middle screw holds the cell in place the three outside screws do the adjustment.

Theres been quite a few mods over the years the most signifigant was these finders. Both a right angle 'scope' and a reflex sight. The original finder was a pair of screw eyes

The reflex sight places a red dot in the sky when you look through it. If all is well place the red dot on an object and it 'should' be centered in the eyepiece. The spotting scope is a bit more accurate and easier to see faint objects.

Of course adding all that weight from the finders to the end of the scope threw it out of balance requiring this kludge. Thats a plastic screw container filled with led shot mixed with expoxy.

Thats about it for now... enjoy !

August · 10-26-09, 10:20 AM

You're a Subsim forum Thomas Edison!

SS107.9MHz · 10-26-09, 10:21 AM

NICE!

Task Force · 10-26-09, 01:49 PM

Nice telescope... so what is its magnification?

SteamWake · 10-26-09, 02:19 PM

Quote:

Originally Posted by Task Force

Nice telescope... so what is its magnification?

Heh... the number one misconception about telescopes.

It all depends on which eye piece you put in. Eyepieces are as varied as the day is long my 'highest magnification' eyepiece is a 7.5mm vixen lanthium which gives and effective magnification of around 162x. At that magnification it is no small feat to keep the object centered in the eyepiece as it will corss the entire field of view in less than 10 seconds. Not to mention getting it centered in that narrow view to begin with.

My favorite eyepiece is the 28mm plossel (university optics). It has a nice field of view passes alot of light and has very little edge distortion thats around 37x and the object stays in the eyepiece for at least 20 seconds. Easier to chase.

It is an f8 at 6" which makes its focal lenght around 48" at that point the incoming start light is focused. Its up to the eyepiece to magnify that focused image.

Its easier to use the calculator web applet instead of going through alot of math...

http://www.csgnetwork.com/telescopemagcalc.html#

By the way it is easy to see jupitor and her moons through the 28mm with the 7.5 you can see the moons shadows on the planet

Not to mention the red spot.

Torplexed · 10-26-09, 07:53 PM

Nice instrument there Steamwake. I imagine you can capture some faint deep sky objects like galaxies and such with that when you set up somewhere rural.

I have an 8" Celestron, but it mostly lives in storage these days.

SteamWake · 10-27-09, 09:23 AM

Quote:

Originally Posted by Torplexed

Nice instrument there Steamwake. I imagine you can capture some faint deep sky objects like galaxies and such with that when you set up somewhere rural.

I have an 8" Celestron, but it mostly lives in storage these days.

Actually some deep sky objects are visible from my back yard Orion nebula is an easy one M31 aka andromida can be seen as a faint smudge but thats another easy one. A few clusters and such under the right conditions.

But I sure know how to bring the clouds and rain

works better than washing the car !.

10-26-09, 09:46 AM	#1
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	My homemade telescope... As promised in another thread here are some shots of my home made telescope. I had to tear her down to get ready for winter and blow out a few cobwebs and such. Only the optics and finders were 'purchased'. It is a 6" f8 newtonian (dobson) reflector. These pictures are a little out of order but its un-important. Front looking down Side view showing the altitude bearings. The round things. It 'glides' on teflon pads which are just visible. The entire base rotates for azimuth adjustments. Your typical dobsonian mount. This is the main mirror and mirror cell resting on the table after cleaning. Another mirror shot this is a vain attempt to show its scale... its 6" Here is a shot of the diagonal mirror holder aka the spider. The diagonal mirror is allegedly optical 'flat' and re-directes the foucus 90 degrees and up the focuser. A peek down the focuser 1.25" ... cobwebs.. yuk. An overall view of the 'tube' its really a box but we still call it a tube This is the ass end of the scope tube showing the collumnation screws. The three screws are adjusted to align the tilt of the main mirror. Here the mirror cell is in place but left loose to show the adjustment screws. A funny side note the screws but up to pennies glued to the mirror cell to keep the screws from digging into the wood. Outside view of the collumnating screws. The middle screw holds the cell in place the three outside screws do the adjustment. Theres been quite a few mods over the years the most signifigant was these finders. Both a right angle 'scope' and a reflex sight. The original finder was a pair of screw eyes The reflex sight places a red dot in the sky when you look through it. If all is well place the red dot on an object and it 'should' be centered in the eyepiece. The spotting scope is a bit more accurate and easier to see faint objects. Of course adding all that weight from the finders to the end of the scope threw it out of balance requiring this kludge. Thats a plastic screw container filled with led shot mixed with expoxy. Thats about it for now... enjoy ! __________________ Follow the progress of Mr. Mulligan : http://www.subsim.com/radioroom/showthread.php?t=147648

10-26-09, 10:20 AM	#2
August Wayfaring Stranger Join Date: Apr 2005 Location: Massachusetts Posts: 23,197 Downloads: 0 Uploads: 0	You're a Subsim forum Thomas Edison! __________________ Flanked by life and the funeral pyre. Putting on a show for you to see.

10-26-09, 10:21 AM	#3
SS107.9MHz Lieutenant Join Date: Aug 2008 Location: Lat.40º12'82"N, Long.8º85'48"W, Portugal Posts: 256 Downloads: 0 Uploads: 0	NICE! __________________ Rádio Universidade de Coimbra 107.9 FM, 26 Years Of Free Radio, http://www.ruc.pt/

10-26-09, 01:49 PM	#4
Task Force Rear Admiral Join Date: Jul 2008 Location: SPACE!!!! Posts: 10,142 Downloads: 85 Uploads: 0	Nice telescope... so what is its magnification? __________________ Task Force industries "Taking control of the world, one mind at a time"

10-26-09, 07:53 PM	#6
Torplexed Let's Sink Sumptin' ! Join Date: Dec 2001 Location: Seattle, WA Posts: 5,823 Downloads: 43 Uploads: 0	Nice instrument there Steamwake. I imagine you can capture some faint deep sky objects like galaxies and such with that when you set up somewhere rural. I have an 8" Celestron, but it mostly lives in storage these days.