Center of Mass

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Greenman Great Britain
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Re: Center of Mass

#21

Post by Greenman »


Interesting project GC, good luck with the final design. I admire your work so far.
Cheers,

Tony.

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Smart Scope: Dwarf II - Club and outreach work.

AP Refractor: Altair 72EDF Deluxe F6;1x & 0.8 Flatteners; Antares Versascope 60mm finder. ASIAir Pro.Li battery pack for grab & go.

Celestron AVX Mount; X-cel LX eyepieces & Barlows 2x 3x, ZWO 2” Filter holder,

Cameras: main DSO ASI533MC; DSO guide ASI120MM; Planetary ASI224MC; DSLR Canon EOS100 stock.

Filters: Astronomik IR cut; Optolong L-Pro; Optolong L-Enhance.

Binoculars: Celestron 15 x 70.

Latitude: 52.219853
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GCoyote United States of America
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Re: Center of Mass

#22

Post by GCoyote »


Pic with the latest changes -
Polar Alignment Scope_20201031.jpg
Any metaphor will tear if stretched over too much reality.
Gary C

Celestron Astro Master 130mm f5 Newtonian GEM
Meade 114-EQ-DH f7.9 Newtonian w/ manual GEM
Bushnell 90mm f13.9 Catadioptric
Gskyer 80mm f5 Alt/Az refractor
Jason 10x50 Binoculars
Celestron 7x50 Binoculars
Svbony 2.1x42 Binoculars
(And a bunch of stuff I'm still trying to fix or find parts for.)
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GCoyote United States of America
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Re: Center of Mass

#23

Post by GCoyote »


I'm waiting on a part to adapt this to a heavier tripod. In the mean time, I have to figure out a way to align the finder scope to perpendicular to the wedge plate. Otherwise my polar alignment will be bogus. I'm guess I could set it up on the patio and use a carpenter's laser level to set up short 'test range'. Have to think about it.
Any metaphor will tear if stretched over too much reality.
Gary C

Celestron Astro Master 130mm f5 Newtonian GEM
Meade 114-EQ-DH f7.9 Newtonian w/ manual GEM
Bushnell 90mm f13.9 Catadioptric
Gskyer 80mm f5 Alt/Az refractor
Jason 10x50 Binoculars
Celestron 7x50 Binoculars
Svbony 2.1x42 Binoculars
(And a bunch of stuff I'm still trying to fix or find parts for.)
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JayTee United States of America
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Re: Center of Mass

#24

Post by JayTee »


Will that 90° adapter let you polar align the mount. I'm having a hard time visualizing this.

JT
∞ Primary Scopes: #1: Celestron CPC1100 #2: 8" f/7.5 Dob #3: CR150HD f/8 6" frac
∞ AP Scopes: #1: TPO 6" f/9 RC #2: ES 102 f/7 APO #3: ES 80mm f/6 APO
∞ G&G Scopes: #1: Meade 102mm f/7.8 #2: Bresser 102mm f/4.5
∞ Guide Scopes: 70 & 80mm fracs -- The El Cheapo Bros.
∞ Mounts: iOptron CEM70AG, SW EQ6, Celestron AVX, SLT & GT (Alt-Az), Meade DS2000
∞ Cameras: #1: ZWO ASI294MC Pro #2: 662MC #3: 120MC, Canon T3i, Orion SSAG, WYZE Cam3
∞ Binos: 10X50,11X70,15X70, 25X100
∞ EPs: ES 2": 21mm 100° & 30mm 82° Pentax XW: 7, 10, 14, & 20mm 70°

Searching the skies since 1966. "I never met a scope I didn't want to keep."

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KathyNS Canada
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Re: Center of Mass

#25

Post by KathyNS »


GCoyote wrote: Tue Nov 03, 2020 3:12 am I'm waiting on a part to adapt this to a heavier tripod. In the mean time, I have to figure out a way to align the finder scope to perpendicular to the wedge plate. Otherwise my polar alignment will be bogus. I'm guess I could set it up on the patio and use a carpenter's laser level to set up short 'test range'. Have to think about it.
Set the wedge up so that the wedge plate is vertical. You will either have to disconnect the turnbuckle or tip the base plate to do it. Use a level to make sure the wedge plate is accurately vertical. Then put the level on the finder to make sure it is horizontal. If there is no convenient place to put the level, sight through it to an object that you have already determined is at the same level.

Then tip the rig on its side and repeat the process for the other direction. The flimsy-looking 90 degree bracket holding the finder looks vulnerable to bending. That is where I would expect most of your PA problems to come from.
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DSO AP: Orion 200mm f/4 Newtonian Astrograph; ATIK 383L+; EFW2 filter wheel; Astrodon Ha,Oiii,LRGB filters; KWIQ/QHY5 guide scope; Planetary AP: Celestron C-11; ZWO ASI120MC; Portable: Celestron C-8 on HEQ5 pro; C-90 on wedge; 20x80 binos; Etc: Canon 350D; Various EPs, etc. Obs: 8' Exploradome; iOptron CEM60 (pier); Helena Observatory (H2O) Astrobin
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GCoyote United States of America
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Re: Center of Mass

#26

Post by GCoyote »


That's roughly the process I had in mind. Didn't consider the 90º rotation though so thanks for that.

The bracket is stiff enough once I get everything squared up. It will bend if bumped, dropped, or too much pressure applied. That works both ways since I can bend it to improve the alignment as well. The alternative is to cut and fasten another block for the finder at a correct right angle. Not my strong suit. :lol:
Any metaphor will tear if stretched over too much reality.
Gary C

Celestron Astro Master 130mm f5 Newtonian GEM
Meade 114-EQ-DH f7.9 Newtonian w/ manual GEM
Bushnell 90mm f13.9 Catadioptric
Gskyer 80mm f5 Alt/Az refractor
Jason 10x50 Binoculars
Celestron 7x50 Binoculars
Svbony 2.1x42 Binoculars
(And a bunch of stuff I'm still trying to fix or find parts for.)
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GCoyote United States of America
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Re: Center of Mass

#27

Post by GCoyote »


n.b. Browsing the Web, EBay suggested a Meade wedge for $289. At the least, this project is helping me understand all the components, how they interact, and the various places where errors can be introduced to the system. Kath's point about turning the wedge 90º is a prime example.

A secondary benefit is remembering some of the shop tricks I was taught 50 years ago. Wow.

In this light, "the project" has already yielded benefits even if the physical artifact ends up being recycled.
Any metaphor will tear if stretched over too much reality.
Gary C

Celestron Astro Master 130mm f5 Newtonian GEM
Meade 114-EQ-DH f7.9 Newtonian w/ manual GEM
Bushnell 90mm f13.9 Catadioptric
Gskyer 80mm f5 Alt/Az refractor
Jason 10x50 Binoculars
Celestron 7x50 Binoculars
Svbony 2.1x42 Binoculars
(And a bunch of stuff I'm still trying to fix or find parts for.)
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