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 | (show all)
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Another Berry-style Refractor Mount new
      #4541844 - 04/24/11 08:34 PM Attachment (334 downloads)

I just finished my second Richard Berry refractor mount and thought I would share a few photos and lessons learned along the way. Two of the hardest parts of fabrication are building the central hub, and drilling the holes for the tripod leg bolts.

The hub is built up by cutting individual pieces from plywood and laminating them together. The issue is consistency in measuring the 120 spacing, and getting accurate cuts. It seems inevitable to have considerable overlap as the layers are glued together, leading to lots of sanding. To solve this problem, I glued the central hub together first, then cut a polygon on the table saw. Very slick. Unfortunately, I either made a measurement error or my original table saw mitre guide failed to cut the proper angle (I have since bought a new mitre guide). So, the legs are not precisely spaced at 120 degree intervals, but at least little sanding was required.

The second issue in fabricating the Berry design it drilling straight and accurate deep holes in the hub for the tripod leg bolts. To solve this issue I used two matched blocks of wood to make each lobe. These were drilled with a forstner bit then glued to the polygonal hub body. I used a biscuit joint for strength, and after the top of the hub was attached I added an additional dowel pin. I found this variation to be extremely successful.

For added rigidity, I upsized all of the hardware from 5/16 to 1/2 bolts, all in bronze sleeve bearings to eliminate wear on the wood. I hardly every use 1/4 in my projects anymore.


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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541855 - 04/24/11 08:38 PM Attachment (207 downloads)

The sleeve bearing for azimuth pin. Another advantage of 1/2 hardware is I can attach my Losmandy GM-8 equatorial head to the tripod with a MA adapter. The Walnut plugs cover dowel pins used to reinforce the leg mount blocks.

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541865 - 04/24/11 08:44 PM Attachment (187 downloads)

On a tip from a CN member who wished to remain anonymous, I used Black Walnut for the legs. This person claimed in quantitive tests this species bested 30 other common hardwood species in damping. I just liked the looks.

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541867 - 04/24/11 08:45 PM Attachment (168 downloads)

This is a spare set of altitude bearings that can attach directly to the Astro-Physics rings that came with my scope. The fit is very tight, and they angle somewhat depending upon how tightly the rings are closed. Seemed like a good idea at the time, but these will sit in the closet in the event I every lose the primary ring set.

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541869 - 04/24/11 08:45 PM Attachment (142 downloads)

And this would be the primary ring set.

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541872 - 04/24/11 08:46 PM Attachment (185 downloads)

And the finished product. I want to build a backgammon table, so I decided to practice some simple wood insets using PurpleHeart, Mahogany, and Black Walnut. Kind of busy looking, but I was having fun.

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541879 - 04/24/11 08:50 PM Attachment (141 downloads)

End view. Ill probably use the remaining PurpleHeart to make a Telrad platform that attaches using Neodymium magnets. Those little suckers are strong!

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541890 - 04/24/11 08:56 PM Attachment (147 downloads)

Front view of the mount. Last Thursday was the shakedown, and I am pleased with the overall rigidity and performance. Tracking was rather easy at 339x. However, the mount is balance sensitive. I can balance to use my heavy widefields, or my lighter Brandons. Using both in the same session is a bit problematic now. Ill have to work on that a bit.

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541897 - 04/24/11 09:00 PM Attachment (158 downloads)

And lastly, a Minimalist Glass Lover's dream. APO doublet, dialectric diagonal, and 48 Brandon. I actually bought the scope because it had about the optimum focal ratio to maximum this eyepiece for my eye.

Dark nebula can run, but they can't hide.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Don W
demi-god
*****

Reged: 05/19/03

Loc: Wisconsin, USA
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4541919 - 04/24/11 09:09 PM

Beautiful job and one of my favorite scopes that I wish I'd never sold.

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

Reged: 07/13/09

Loc: Parsippany NJ, USA
Re: Another Berry-style Refractor Mount new [Re: Don W]
      #4541969 - 04/24/11 09:28 PM

This scope is really lucky to be mounted on such a beautiful mount!

Alex


Post Extras: Print Post   Remind Me!   Notify Moderator  
StarStuff1
Post Laureate
*****

Reged: 04/01/07

Loc: South of the Mason-Dixon Line
Re: Another Berry-style Refractor Mount new [Re: Don W]
      #4541970 - 04/24/11 09:28 PM

Nice work! Beautiful form and great function.

Post Extras: Print Post   Remind Me!   Notify Moderator  
plyscope
Pooh-Bah


Reged: 11/23/06

Loc: Perth, West Australia
Re: Another Berry-style Refractor Mount new [Re: StarStuff1]
      #4542019 - 04/24/11 09:56 PM

That is a really nice mount Jeff. Thanks for the great pictures. I am planning another Berry mount for a 5" achromat. This thread is great inspiration.

Andy


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr Magoo
Carpal Tunnel
*****

Reged: 11/05/05

Loc: Franklin, Indiana
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4542039 - 04/24/11 10:05 PM

Very nice work Jeff. A question, how do you determine the length of the counterweight tray?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Andrews
Pooh-Bah
*****

Reged: 01/25/07

Loc: Albuquerque, NM
Re: Another Berry-style Refractor Mount [Re: Mr Magoo]
      #4542136 - 04/24/11 10:51 PM

Truly awesome build! Gorgeous.

Makes me want to buy a refractor just to have an excuse to build one of those!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Brian Reed

*****

Reged: 10/29/04

Loc: North East Illinois
Re: Another Berry-style Refractor Mount new [Re: Tom Andrews]
      #4542161 - 04/24/11 11:04 PM

The inlay is stunning. Awesome Job!!!

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

Reged: 09/28/03

Loc: Prescott, AZ
Re: Another Berry-style Refractor Mount new [Re: Mr Magoo]
      #4542510 - 04/25/11 05:23 AM Attachment (108 downloads)

Quote:

Very nice work Jeff. A question, how do you determine the length of the counterweight tray?




Thanks guys!

As to the length of the cradle, there really is no set dimension. It's function is to hold the tube on one end, and counterweight on the other. So if you make it long you can get by with a smaller weight, but it is more cumbersome to transport. Make it short, and you need a heavier weight. There are a couple of other options:

1) Eliminate it completely and do the "Weightless Woodshop Refractor" style that Chuck Hard had published in S&T. Basically, the overhang is replaced by a teflon tipped hook that catches under the hub. I built my first one like this, it works well (photo attached). Come to think of it, I can't recall why I did not do this one that way.

2) Truncate the extension and mount a horizontal counterweight shaft. My Star12 only weighs 11 pounds (call it 13 operational weight) so a steel shaft by itself would almost be enough.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mr Magoo
Carpal Tunnel
*****

Reged: 11/05/05

Loc: Franklin, Indiana
Re: Another Berry-style Refractor Mount new [Re: Jeff Morgan]
      #4542521 - 04/25/11 05:33 AM

Thanks Jeff. I really like the hook idea. I had not seen that article.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob Myler
Pooh-Bah
*****

Reged: 05/18/06

Loc: St Louis, MO
Re: Another Berry-style Refractor Mount new [Re: Mr Magoo]
      #4544004 - 04/25/11 08:45 PM

Simply stunning work. I understand that accurately drilling 5-1/2" straight through each leg hub is an iffy proposition at best - especially since you can't vertically square Berry's trefoil hub on a drill press. Somewhat akin to drilling thru a mountain and hoping you arrive at the right place on the other side.

Jeff, your solution is elegant and makes much more sense.


Post Extras: Print Post   Remind Me!   Notify Moderator  
plyscope
Pooh-Bah


Reged: 11/23/06

Loc: Perth, West Australia
Re: Another Berry-style Refractor Mount new [Re: Bob Myler]
      #4544188 - 04/25/11 10:07 PM

Some more apo's on Berry mounts but I like yours better Jeff!
AP and TMB on Berry

Andy


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
3 registered and 16 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: 4615

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics