i built two of these about the same time a little over a year ago.

 they are made from welded aluminum squarewall tubing and carbon fiber truss tubes

 the optics are 18" f/4.2 primary and a 3x secondary for a final ratio of f/12.6

 serial number 1

http://www.narrowbandimaging.com/mark_i_classical_cassegrain_hex_page.htm

 serial number 2

http://www.narrowbandimaging.com/mk1sn2_page.htm

 here are images taken using SN2:

http://www.narrowbandimaging.com/Stinger_gallery_page.htm

thanks for looking.

rdc

Well done! Very nice work! I need to spend some time looking through your web site. John

All I can say is 'WOW!"

I'm a newbie just getting started and will be sticking with binoculars for awhile but this is really inspiring to see! I had no idea a home built scope could see such images!

Well done!

East_McDuck wrote:

Wow, that is very impressive for a home made telescope.  If you don't mind my asking, how much of an investment was that?  That is something i would definitely like to look into in the future.

 it took me about 100-120 hours to complete and about $7500 in materials

I have a second one I am considering selling for in the range of $10,000

Kinjari wrote:

All I can say is 'WOW!" I'm a newbie just getting started and will be sticking with binoculars for awhile but this is really inspiring to see! I had no idea a home built scope could see such images! Well done!

Well thanks. you'd be surprised what you can do with a well made home built telescope and a good mount under decent conditions....

 I shot all those images from my backyard in the light polluted suburbs in the San Francisco bay area (not far from Oakland and Hayward).

here's a recent pair from the same scope:

http://www.narrowbandimaging.com/m27_mk1sn2_dm_geg_cs4_s2hao3_page.htm

http://www.narrowbandimaging.com/sh2_54_mk1sn2_dm_geg_cs4_ha_page.htm

Always loved the classical cass and every time I climb the 8-foot ladder to the eyepiece of my 16" f/7, I kick myself at each step!  An article of my first cass is here:

http://www.tnni.net/~dustymars/misc/Cass_Equ.htm

I was planning on using the 16" for an f/4 - f/50 setup, but Parker talked me into a Newtonian!  We used to photograph Mars from Lowell, Cerro Tololo and Mauna Kea using a 24" f/75 casses with a nice image size for the film at prime focus! 

Nice telescopes you have.

Jeff

dustymars wrote:

Always loved the classical cass and every time I climb the 8-foot ladder to the eyepiece of my 16" f/7, I kick myself at each step!  An article of my first cass is here: http://www.tnni.net/~dustymars/misc/Cass_Equ.htm I was planning on using the 16" for an f/4 - f/50 setup, but Parker talked me into a Newtonian!  We used to photograph Mars from Lowell, Cerro Tololo and Mauna Kea using a 24" f/75 casses with a nice image size for the film at prime focus!  Nice telescopes you have. Jeff

And that's a nice writeup you created too Jeff.

One book I like and recommend is Pierre Bely's "Design and Construction of Large Optical Telescopes" published by Springer

Even though my interest is imaging I have used mine visually and had a blast. My dob-buddies were remarking how nice it was to be able to sit on a chair on the GROUND to observe instead of climbing ladders in the dark

LOL, sitting down and looking through the bottom end of a tube is nice.

What mount is it sitting on? Looks like an AP in the pictures. What sort of OTA weight did you end up with? 

johnm wrote:

LOL, sitting down and looking through the bottom end of a tube is nice. What mount is it sitting on? Looks like an AP in the pictures. What sort of OTA weight did you end up with?

The Mount is an AP1200GTO.

 The OTA is about 110# total

While complaining about the ladder climb Don pointed out that sitting while observing may not be so great.  When I used my 12.5" cass, several years, I was a lot younger then, but now we have both traversed by the medicare generation and sitting too much really gets to us.  At any rate the 16" f/50 would have had a small obstruction and imaging with it may have been a treat.  The problem with a couple of the "Patrol" scoeps, 24" f/75, was the bridge builders that put them together used a large aluminum disk to hold the 1.6-inch secondary on to the upper tube -- so goes teh low obstruction!     

After I get the new notebook and Vista to ToUcam drivers in and all the bugs I hear about MS's new stuff, I will start imaging again.  The problem before was an old PC with a low res screen and focusing was nearly impossible.  Parker and I are working on some solutions for higher resolution web-cam imaging, so maybe my back lot will not be cluttered with throw away cameras

Jeff  

When my first Cass was made it was not really all that great for Mars.  After Rich Berry came out with Telescope making, the first issue was on designing Cassegrains so that got me thinking about re-configuring my f/16 to a longer f/r.   Clyde Tombaugh was instrumental in the concepts of Lowell's International Planetary Patrol f/75 cameras and told me once they should have gone for an f/100 system!  Anyway, the guy who did my optics made a new 2" f/30 secondary for my system and it improved my observing a whole lot.

One reason for that article came about after asking Kalmbach or Astronomy to publish Berry's TM's in book form, but they refused, so I just took the good stuff and wrote it in that article. TM's are hard to find and there is so much great information in them that some of it should be published again.  

BTW, my baffle tune was PVC and eve using flat black paint some scatter could be seen. So, treading the inside in a lathe solved that.  

 Jeff

dustymars wrote:

When my first Cass was made it was not really all that great for Mars.  After Rich Berry came out with Telescope making, the first issue was on designing Cassegrains so that got me thinking about re-configuring my f/16 to a longer f/r.   Clyde Tombaugh was instrumental in the concepts of Lowell's International Planetary Patrol f/75 cameras and told me once they should have gone for an f/100 system!  Anyway, the guy who did my optics made a new 2" f/30 secondary for my system and it improved my observing a whole lot. One reason for that article came about after asking Kalmbach or Astronomy to publish Berry's TM's in book form, but they refused, so I just took the good stuff and wrote it in that article. TM's are hard to find and there is so much great information in them that some of it should be published again.   BTW, my baffle tune was PVC and eve using flat black paint some scatter could be seen. So, treading the inside in a lathe solved that.    Jeff

Benoit Schillings suggested a nice way to kill reflections in the baffle systems. He buys non-skid porch step paint from Orchard Supply, paints that on the optical surfaces (really rough finish) and then sprays flat-black paint over it. He said it is every bit as non-reflective as the flocking paper and doesn't hafve the adhesion problems etc from the paper.

I haven't tried it yet but plan to next time I take the cassegrain apart.

Wow, Richard, your web site is one of he, if not the, most comprehensive and informative on the Net!   I will send the URL to Tippy D'Auria, who retired last year and is setting up his new observing site at his new home in Ocala.  He asks me questions that you have answers to!

Thanks,

 Jeff

Richard Crisp wrote:

East_McDuck wrote: Wow, that is very impressive for a home made telescope.  If you don't mind my asking, how much of an investment was that?  That is something i would definitely like to look into in the future.    it took me about 100-120 hours to complete and about $7500 in materials   I have a second one I am considering selling for in the range of $10,000

Let me get rich first, then we'll talk.  Until then, I have to stick with my $300 Walmart special.  

Very impressive scopes and images you have Richard, you have some serious talent there. Where`s the best place to get info and plans on building a cassegrain? I prefer to be grounded when viewing and not up a ladder, thanks,

Kayne.

What's the point of that black tube sticking out of the primary mirror?

Kyle:

What's the point of that black tube sticking out of the primary mirror?

that is the main baffle tube. Cassegrains need them to prevent sky flooding. Without the baffle the light from the sky can shine directly onto the sensor without traversing the designed path using the mirrors.

Wow! Excellent pictures and a beautiful scope!!! Great Job Rich!

Is it for sale?   :P