Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> ATM, Optics and DIY Forum

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | (show all)
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6095805 - 09/22/13 09:25 PM Attachment (37 downloads)

I added mounting tabs to the bottom of the UTA. I wanted to make sure that the trusses were angled in one axis only. I got pretty close!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6095831 - 09/22/13 09:34 PM

The secondary holder was constructed from parts I had laying around. One part was pretty crazy, I had a magnesium base from a Monfrotto tripod head that was reversible for 3/8" or 1/4-20. That became the top mounting disk. 4 8/32 threaded rods, some thumbwheels and some springs from every click-pen we had in the house. The mirror holder is cut from a piece of PVC tubing on my chopsaw. All in all, everything made for a nice secondary holder! I don't know that I could make another like it in my lifetime though!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6095850 - 09/22/13 09:49 PM Attachment (27 downloads)

Last for this weekend is the construction of a three curbed-vane spider. I wasn't going to do a curved vane spider originally, but I was going through my scrap shelf and found a 2" thick section of 7" diameter tube from my refractor build. The thing i hate most about curved vane spiders is forming the curve and for a span as long as 17", any excess curvature beyond the main curve will affect the final image. My last curved vane spider had one vane torqued a bit which caused a flare in dark skies.

I figured if I could cut the section into two 1" rings and cut each ring in half, I could have three vanes with curves that I know maintain their parallelism with each other.

My favorite way to cut tubing is using a hacksaw, using hoseclamp as guide. I get perfectly square cuts. Then each ring is cut in half...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6095860 - 09/22/13 09:53 PM Attachment (23 downloads)

For the hub I had a 1" dia 1/8" wall aluminum tube that was originally a roller for some piece of manufacturing equipment. I had a couple of aluminum washers that I press-fit into each end(again, pure luck that they fit!) and I drilled the center to fit a 3/8" shaft. I marked the 120deg sections and started drilling and tapping...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6095864 - 09/22/13 09:55 PM Attachment (35 downloads)

Another view...


It turned out well. Stiff enough (you can see the secondary holder in the background). If it doesn't work, I might end up buying a 4 vaned straight spider and commercial secondary holder.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6096063 - 09/22/13 11:59 PM

Quote:

My deadline for first-light is the Illinois Dark Sky Star Party Oct 6th-ish. Hopefully a deadline will help! I have been working on all the little parts. What you gain in portability with truss construction, you pay for in complexity.




October 6th is coming up pretty fast ...

Good luck on the truss connectors. After my third failure at making my own, I vowed to buy that part commercial in all future scopes. I burned up a lot of days in the shop trying to get a functional and attractive solution - to no avail. I hope your experience is better.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Jeff Morgan]
      #6097961 - 09/24/13 08:29 AM

I was up pretty late last night(or early this morning) trying to mock up the OTA. My truss connectors aren't going to do the trick, at least not how I had intended. There is too much force for the clamping action to handle and the tubes slide and twist too easily. Fixing that is going to require pinning each tube into either bracket end Not the end of the world, but not the super cool adjustability I was shooting for. Oh well, I make the mistakes so you don't have to!

Edited by Sean Cunneen (09/24/13 01:12 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6098334 - 09/24/13 11:54 AM

Don't feel too bad. I recall Dave Kriege at AstroFest 20 years ago saying that it took him three prototypes on the Obsession design.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Jeff Morgan]
      #6098466 - 09/24/13 01:15 PM

The fix isn't too bad. I was thinking almost solely in terms of compression and standing straight up the assembly was a piece of cake and the OTA looked great! As I moved it to horizontal so I could find the balance point, everything turned into limp spaghetti and I had tubes coming apart all over. All I could hear was the Benny Hill theme as I tried to wrangle 3 poles with two hands!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6132236 - 10/11/13 11:36 PM Attachment (24 downloads)

Okay, I admit it, this post jumps the gun a bit, but at least you see it is a scope!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6132237 - 10/11/13 11:36 PM Attachment (22 downloads)

Doesn't look quite so huge in this pic...

Post Extras: Print Post   Remind Me!   Notify Moderator  
magic612
Post Laureate
*****

Reged: 09/30/08

Loc: S. of Chicago's light dome
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6132248 - 10/11/13 11:42 PM

Sean. like I said on Facebook: Ladder.

Or should I say: TALL LADDER!!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: My 16" f7.2 Newt project code named "Grace" new [Re: magic612]
      #6132265 - 10/11/13 11:55 PM Attachment (19 downloads)

Quote:

Sean. like I said on Facebook: Ladder.

Or should I say: TALL LADDER!!






Congrats Sean!

Here is a ladder worthy of such a scope. The tape measure I am holding is set to 110", the original planned eyepiece height of my 16" f/7 scope Stripe.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Jeff Morgan]
      #6132308 - 10/12/13 12:29 AM

I tried grabbing one of those Home Depot stocking ladders but the guards caught me before I could get it in the car.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mirzam
Post Laureate
*****

Reged: 04/01/08

Loc: Lovettsville, VA
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Sean Cunneen]
      #6132588 - 10/12/13 08:35 AM

Holy elevator shoes Batman!

JimC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pinbout
Postmaster
*****

Reged: 02/22/10

Loc: nj
Re: My 16" f7.2 Newt project code named "Grace" new [Re: magic612]
      #6132633 - 10/12/13 09:14 AM

Quote:

Sean. like I said on Facebook: Ladder.

Or should I say: TALL LADDER!!




facebook is for oldtimers

kids say hashtag #tall ladders.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Darren Drake
Carpal Tunnel
*****

Reged: 10/09/02

Loc: Chicagoland
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Pinbout]
      #6132880 - 10/12/13 11:38 AM

Looking forward to looking through it very soon!

Post Extras: Print Post   Remind Me!   Notify Moderator  
azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Darren Drake]
      #6133967 - 10/12/13 10:24 PM

These 16" f/7s are my dream scopes - it was the largest I thought Id go if I were to go in that direction. As it is Ive been too busy and honestly, happy with the 8" F/9 bit I do envy you guys with those awesome systems. Great work on both 16s.

Pete


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: My 16" f7.2 Newt project code named "Grace" new [Re: azure1961p]
      #6134095 - 10/12/13 11:59 PM

Quote:

These 16" f/7s are my dream scopes - it was the largest I thought Id go if I were to go in that direction. As it is Ive been too busy and honestly, happy with the 8" F/9 bit I do envy you guys with those awesome systems. Great work on both 16s.

Pete




Thats so funny ... we have a sloped property, and the limited flat spots are just too small for Stripe (and the accompanying ladder). So Stripe is strictly a remote session telescope.

But I often wake up in the early morning and need a scope for quick yard sessions. I have been sketching out a solution to this problem over the past couple of weeks. No ladder is one requirement, the other is fast and easy set -up. The solution I am closing in on is a 8" f/9 scope!

At some point, I will become too old and frail to use my 16" f/7, at which point it will come up for sale. But since Clyde Tombaugh used his long focus 16" well into his 80's .... don't hold your breath.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sean Cunneen
Let Me Think
*****

Reged: 08/01/07

Loc: Blue Island Illinois
Re: My 16" f7.2 Newt project code named "Grace" new [Re: Jeff Morgan]
      #6340830 - 01/28/14 12:11 PM Attachment (15 downloads)

I have spent a good month working on this project however I had a catastrophic Update with my computer which deleted all pictures of the finishing steps Here is a photo of the UTA and LTA together...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | (show all)


Extra information
17 registered and 19 anonymous users are browsing this forum.

Moderator:  ausastronomer, richard7, Starman81 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 5806

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics