Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

New ES 140mm f6.5 FPL-53 Scope - Pictures and Impressions

  • Please log in to reply
98 replies to this topic

#51 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 14 February 2019 - 07:34 PM

WOW...beautiful scope. You are going to have a lifetime of wonderful views/images. ES hit this one out of the park if it performs as well it looks.

FTLAUDSKY,

Thanks! It is a thing of beauty. Love this scope so far :) It needs a lot more testing, but I think this scope will be a keeper for a very long time. I'm hoping my AP skills will be worthy of this scope lol

 

Regards,

Skyhunter1



#52 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 14 February 2019 - 09:31 PM

Hey - fabulous scope and I like this thread!  I just purchased a 102mm Essentials triplet directly from ES(silver grade refurb) and scored a great deal on it!  Not as nice as your rig but Im in the ES club so to speak now.  Will have it next week and with some luck I can post pics and a quick view report if my upstate, NY weather cooperates, lol!

Mike,

Thanks for the compliment for my new baby smile.gif That 102mm essentials is gonna be great. Congratulations!, I look forward to seeing how you like it 

 

The tube rings on my ES ED 152 had only one 6mm threaded hole in each ring.  There were also two smaller unthreaded holes in each ring beside the threaded hole.  I threaded the other four holes to 6mm.  The rings are now held on to the dovetail by six bolts to a 1/2 inch thick solid  aluminum alloy plate machined to Vixen size to fit my Atlas mount.  Rings are 11 inches.apart center to center. The OTA feels very secure.  I think the rigidity of the plate has a lot to do with it.  Some of the stock Vixen style plates are not solid, and look extruded.  My plate is heavy.

John,

After some of the comments I did put a Losmandy plate on this scope. It is better and feels more stable, but I may ask my best friend who is a carpenter to add the holes as you have. I don't have the tools for that modification. I'd feel better with a couple of more screws at least... I'm sure its fine... but why not? I don't think it'll take my friend that long..

 

I know my Losmandy plate is aluminum... Do you know what metal the rings are made of? Thanks...

 

Regards,

Skyhunter1


Edited by SkyHunter1, 14 February 2019 - 09:35 PM.

  • 25585 likes this

#53 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 7043
  • Joined: 04 Jan 2004
  • Loc: ROR Obs. near Pettigrew, AR

Posted 14 February 2019 - 10:15 PM

Mike,

Thanks for the compliment for my new baby smile.gif That 102mm essentials is gonna be great. Congratulations!, I look forward to seeing how you like it 

 

John,

After some of the comments I did put a Losmandy plate on this scope. It is better and feels more stable, but I may ask my best friend who is a carpenter to add the holes as you have. I don't have the tools for that modification. I'd feel better with a couple of more screws at least... I'm sure its fine... but why not? I don't think it'll take my friend that long..

 

I know my Losmandy plate is aluminum... Do you know what metal the rings are made of? Thanks...

 

Regards,

Skyhunter1

Aluminum.  My Atlas as is only takes a Vixen style dovetail.  The custom machined solid Vixen style dovetail I have is stronger than the mount saddle.   It's the best I can do.


Edited by John Fitzgerald, 14 February 2019 - 10:18 PM.

  • SkyHunter1 likes this

#54 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 15 February 2019 - 10:16 AM

John, 

Thanks for letting me know. Aluminum should be easy enough as its a soft metal. The rings seemed like they were some kind of die-cast metal at first. Definitely will get that mod done. I appreciate your help.

 

Regards,

Skyhunter1



#55 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 15 February 2019 - 10:26 AM

Hello All,

Got the .7 Reducer from Explore Scientific today for my ED140. They were gracious enough to let me test and see if it works since they don't have a focal reducer for this scope at the moment. 

 

The packaging is nice and the reducer is big... Never seen a 3" reducer before. You can get some idea of the size from the pics. Optics look great. Super sharp and clear. As mentioned above, I believe that this reducer will work fine with the ED140.

 

f/4.5 @ 637mm @ 1.5 arcsec/px. I think its gonna be great to image at that FL and FR while still maintaining resolution. It's all about fast for my imaging technique :)

 

Enjoy the pics and if there's any questions, feel free to ask as always.

 

Also, I want to thank the community for their suggestions on how to make this setup better and more stable... Keep it coming!

 

Regards,

Skyhunter1

 

Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos

  • Bomber Bob likes this

#56 droe

droe

    Viking 1

  • *****
  • Posts: 866
  • Joined: 01 Jul 2015
  • Loc: Fenton, Mi

Posted 15 February 2019 - 02:44 PM

That looks awesome. 

 

Remember, after you pull the pin, throw it at least 30 yards and take cover.


  • SkyHunter1 likes this

#57 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 15 February 2019 - 03:01 PM

That looks awesome. 

 

Remember, after you pull the pin, throw it at least 30 yards and take cover.

Hahahhahahahaha :) That's classic lol.gif ..  It does look like that. I've thrown some grenades and it never occurred to me lol.

 

Regards,

Skyhunter1


  • droe likes this

#58 SilverLitz

SilverLitz

    Mariner 2

  • -----
  • Posts: 294
  • Joined: 17 Feb 2018
  • Loc: Louisville, KY

Posted 15 February 2019 - 05:18 PM

John, 

Thanks for letting me know. Aluminum should be easy enough as its a soft metal. The rings seemed like they were some kind of die-cast metal at first. Definitely will get that mod done. I appreciate your help.

 

Regards,

Skyhunter1

Aluminum is soft, BUT it is "gummy" and this makes it somewhat difficult to work with.  Years ago, I built my own audio amplifiers/pre-amps using 1/8" aluminum angle and aluminum heatsinks, and aluminum's "gummy" nature caused many drill-bits and taps to snap.  If you work with aluminum, take it slow (drill very little in, then back out, and then in some more), use cutting oil to lubricate the bit/tap, and most definitely use a drill press.  If you tap the holes, have a good tap wrench, use cutting oil, and go slow as well.



#59 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 16 February 2019 - 01:53 PM

Aluminum is soft, BUT it is "gummy" and this makes it somewhat difficult to work with.  Years ago, I built my own audio amplifiers/pre-amps using 1/8" aluminum angle and aluminum heatsinks, and aluminum's "gummy" nature caused many drill-bits and taps to snap.  If you work with aluminum, take it slow (drill very little in, then back out, and then in some more), use cutting oil to lubricate the bit/tap, and most definitely use a drill press.  If you tap the holes, have a good tap wrench, use cutting oil, and go slow as well.

Silver,

Thanks so much for the info. I don't want to do a hack job on the rings... I'll give my friend the info to make sure we do it right. John in the above thread private messaged me with some good info as well.

 

Thanks so much to this amazing community for all your help :)

 

Regards,

Skyhunter1



#60 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 18 February 2019 - 11:42 AM

All,

Does anyone have any information or know where I can find any information regarding adjusting the focuser for the ES scopes? And specifically the hex focuser? My focuser is smooth but a little tight and I believe it can be adjusted to loosen it up a little. I'm skiddish to start messing with it, but maybe I can get some input here. 

 

Thanks in advance to everyone. There's been so much good advice to get this scope optimized.

 

Regards,

Skyhunter1



#61 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 02 March 2019 - 01:34 PM

I'm back.... The weather has not been cooperating at all. I am only able to image on Friday or Saturday nights at Jones Beach LI and I've been having no luck...

 

Explore Scientific ED140 Apo Refractor Review Photos
 
I'll do my best to get some images posted as soon as I can...
 
Regards,
Skyhunter1


#62 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1895
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 02 March 2019 - 10:00 PM

 

I'm back.... The weather has not been cooperating at all. I am only able to image on Friday or Saturday nights at Jones Beach LI and I've been having no luck...

 

 
 
I'll do my best to get some images posted as soon as I can...
 
Regards,
Skyhunter1

 

Hah, your weather forecast looks about as enticing as mine lately.  Geesh.  I’m like 3 weeks straight now of not being able to even sneak in a first light of any kind.  Just atrocious.  

 

Please do post pics....love to see them! 


Edited by Mr. Mike, 02 March 2019 - 10:00 PM.

  • SkyHunter1 likes this

#63 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 03 March 2019 - 12:50 PM

Hah, your weather forecast looks about as enticing as mine lately.  Geesh.  I’m like 3 weeks straight now of not being able to even sneak in a first light of any kind.  Just atrocious.  

 

Please do post pics....love to see them! 

Mike,

We're definitely not alone here in NY. It's reached deep levels of desperation for some... Check out the post started today below:

 

It's been cloudy for so long, I feel like selling everything!
Alnitak2009 - Today, 12:00 PM

General Observing and Astronomy

 

https://www.cloudyni...ing-everything/

 

We may need to have an intervention with this poor soul if we even make it ourselves...

 

Regards,

Skyhunter1


Edited by SkyHunter1, 03 March 2019 - 12:51 PM.

  • Mr. Mike and Bomber Bob like this

#64 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1895
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 03 March 2019 - 01:33 PM

Mike,

We're definitely not alone here in NY. It's reached deep levels of desperation for some... Check out the post started today below:

 

It's been cloudy for so long, I feel like selling everything!
Alnitak2009 - Today, 12:00 PM

General Observing and Astronomy

 

https://www.cloudyni...ing-everything/

 

We may need to have an intervention with this poor soul if we even make it ourselves...

 

Regards,

Skyhunter1

Geesh.  Can’t say I’m happy that you guys are also in the same boat.  This sucks.  Like really sucks.  I’m about ready to point the thing at some birds in my spruce trees just for the helluva it!  My forecast shows a possible chance tomorrow night but I’ve seen such reports before only to be screwed anyways. 

 

Killing me......mad.gif



#65 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 11 March 2019 - 08:43 PM

Hello all, I'm back. Unfortunately the weather has continued to be horrible here in NY. Hopefully I'll get some pics soon.

 

I called ES to see if there was any way to adjust the 3" hex focuser so it wouldn't be as tight. Kent told me that if you remove the focuser by removing the 3 screws that allow the focuser to rotate, there will be 2 screws. The silver screw marked by the red arrow on the focuser will be visible when removed and can be loosened or tightened to adjust the tightness of the focuser and how easily it rotates. The black thumbscrew marked in blue is the tension screw. It will increase the tension of the focuser to where the focuser will become harder to rotate but still not lock the focuser. The white arrow is an actual marking on the scope and denotes the "normal" or home position, for lack of a better term.

 

Explore Scientific ED140 Apo Refractor Review Photos

 

So, on the hex focuser, to increase/decrease the OVERALL tension you can remove the focuser and adjust the silver screw marked by the red arrow. Once the focuser is re-assembled, the tension screw is used to increase or decrease tension as we get closer to focus, but will still allow movement of the focuser. Underneath the focus knobs, there is a locking screw. I included a pic but didn't mark the locking screw. The locking screw will lock the focuser as you might suspect. It is the thumbscrew directly in between the 2 silver focus knobs although its hard to see.

 

ES ED140 f6.5 FPL-53 Refractor
 

The focuser is looser now and it feels better to my touch than before. It's no feathertouch, but still solid and smooth with no image shift. My friend who buys and sells scopes came over to check out the ED140 and said "this thing is built like a tank" regarding the hex focuser.

 

As an aside, my friend the carpenter will be adding additional screws to the mounting plate as was suggested earlier in the thread. I have to get it to him to make the modification and will post pics of the mod when it's completed.

 

Kent from ES is also trying to get an optics report for my scope. If I am able to get one I'll post that as well. I'm keeping my fingers crossed smile.gif

 

Regards,
Skyhunter1

 

Explore Scientific ED140 Apo Refractor Review Photos

Explore Scientific ED140 Apo Refractor Review Photos


Edited by SkyHunter1, 11 March 2019 - 08:45 PM.

  • eros312 likes this

#66 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 19 March 2019 - 12:01 AM

Hello All,
Finally had a clear night here in NY, so I was finally able to attempt some imaging with my new baby.

 

I went last night (Sun 3/17) to my imaging site on Jones Beach LI. Unfortunately It was very cold, the moon was at 89% illumination and the winds were higher than the weather report had indicated. My goal was to get the moon and Orion using the .7 focal reducer that ES had loaned me to see if it worked with this scope. I was using the ZWO 294mc and my buddy was using my ZWO 183mc on his ES 80mm scope on the Horse Head Nebula.

 

I was able to get the image below of the moon thru the ED140. The view was stunning to say the least. My buddy agreed that it was gorgeous thru this scope. I am unable to find any false color in this image. The crater edges and the edges of the moon itself are aberration free to my eyes, but you be the judge. I am including 2 different processes of the same image.

 

Explore Scientific ED140 Apo Refractor Review Photos
Explore Scientific ED140 Apo Refractor Review Photos
 

Next, I wanted to get a couple of hours on Orion with the .7 reducer. unfortunately my buddy had issues on his laptop with the ZWO 183mc. I was able to resolve the issue but had lost precious time. I finally slewed to Orion and started to attempt focus. I tried for a half hour to get into focus, but was unable to get the trapezium stars to become pinpricks and split. There was a bloating that I was unable to eliminate in the stars. I was using the specified 55mm back-focus (17.5mm for the 294mc, a 30mm spacer, and 6.5mm from the reducer using the 2" adapter as per ES website)

 

After all of this Orion was too far in the west and I would have to use the reducer for such a huge target, and wasn't having any luck. Between the wind and the cold and the moonlight from an almost full moon, we decided to pack it in around 10:30pm.

 

After some discussion with my buddy, we were both pretty sure that the reducer's backfocus may need to be adjusted to be optimal with this scope. I will try to determine the proper spacing in the next week or so. There were no issues with the scope visually and was sharp as a tack on the moon and Orion, so I will need to experiment more with this reducer before I make the determination that it won't pair with this scope.

 

As an aside,  I bought a Polemaster for my Atlas mount to get better polar alignment. It was first light for this camera. It worked flawlessly... worth every penny for the precise PA I was able to achieve. It was so easy to use it shocked even me. If you've been considering one, think no more and get one, you won't be sorry. Amazing product.

 

Still trying to get the optics report and will be trying again to image soon as the weather becomes more agreeable. I'll post any info or images I get. Clear skies all!!!

 

Regards,
Skyhunter1


  • Mr. Mike, nicknacknock and Bomber Bob like this

#67 woody wood

woody wood

    Lift Off

  • *****
  • Posts: 5
  • Joined: 03 May 2012

Posted 19 March 2019 - 08:15 PM

Great shots!!

 

Cant wait to see some DSOs. 



#68 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 21 March 2019 - 12:18 PM

Thanks wood!

I appreciate the compliment. I think the lunar shots came out very well (IMO) with the ED140 and the 294. I think the 183 will be even better :) higher resolution and smaller chip to draw it in a little more. The 294 is a better DSO camera, but for a bright target like the moon, I'm thinking the 183 will shine.

 

Hoping to get some DSOs soon. I think in April I'll be able to get out a couple of times and work out the issues with the focal reducer. I wont lose another night over it though. Worst case I'll just image without it.

 

Thinking about M63, 51, Leo Triplet, maybe Markarian's Chain.

 

Anyone have any suggestions for good targets (galaxy or nebular) in the south or high in the sky/approaching the zenith around 8pm - 1 am EST? in the next month or two? I'm imaging from Long Island NY.

 

The south is the darkest direction for me because its over the ocean. Targets near the zenith work well too. 

 

Regards,

Skyhunter1



#69 gnowellsct

gnowellsct

    Hubble

  • *****
  • Posts: 15963
  • Joined: 24 Jun 2009

Posted 21 March 2019 - 11:26 PM

Mike,

Thanks for the compliment for my new baby smile.gif That 102mm essentials is gonna be great. Congratulations!, I look forward to seeing how you like it 

 

John,

After some of the comments I did put a Losmandy plate on this scope. It is better and feels more stable, but I may ask my best friend who is a carpenter to add the holes as you have. I don't have the tools for that modification. I'd feel better with a couple of more screws at least... I'm sure its fine... but why not? I don't think it'll take my friend that long..

 

I know my Losmandy plate is aluminum... Do you know what metal the rings are made of? Thanks...

 

Regards,

Skyhunter1

A 1/4 20 screw is more than enough to hold a scope.  There is an advantage in that a single bolt in center ring can adjust its angle to the tube.  If you screw in two screws tight it is the tube that will have to adjust to the rings.  My GT130 is held on to the Losmandy dovetail by two rings, each with one screw.  This is also true of the top rail.  In fact if your top rail has four screws and your bottom rings are held in by 4 screws you now have the potential for slight misalignments to be working in opposite directions.  

 

My 2c....

 

I'm assuming I understand you correctly, that you want more than one screw in each ring rather than the center screw.  

 

GN


  • CounterWeight and SkyHunter1 like this

#70 gnowellsct

gnowellsct

    Hubble

  • *****
  • Posts: 15963
  • Joined: 24 Jun 2009

Posted 22 March 2019 - 12:08 AM

That moon shot looks like a one degree field or so, implying a magnification of about 70x or 0.5x per mm of aperture.  To get a "tough" lunar limb color test you should push it to 2x per mm or about 280x.  Should be doable.  Or during the day find a distant tree branch against the bright blue sky.

 

This is a pricey triplet apo and it will, in my estimation, pass such color tests, but an almost-full moon in the field of view indicates this test did not push the optics hard. 

 

2x per mm of aperture corresponds to a 0.5 mm exit pupil in every scope, and the 50x per inch rule is just an Americanization of the measurement.  The 1x per mm of aperture is always a 1 mm exit pupil.  A 6.5 mm eyepiece in your scope will yield exactly 140x.  And although a 3.25 mm eyepiece might be hard to find a 3.5mm or 3.0 mm will be close enough to the 0.5 mm exit pupil or 2x per inch (280x).  

 

The idea of color testing at high magnifications is that the R G B don't come together at exactly the same point in an imperfectly corrected scope.    High magnifications are unforgiving in terms of getting exact placement of the eyepiece relative to the focal plane, and either all the color is exactly there or it isn't.  If it isn't, you get false color fringe.  At low magnifications the focus position is more forgiving, it is easier to find a sharp focus point for lunar features (for example) and more difficult to detect whether one color is coming to the focus point in front or behind of the others.  That is, it's harder to see false color.  In fact even f/5 or f/6 achromats at very low magnifications exhibit little false color on run of the mill star fields. 

 

The ES 140 triplet will do much better.  The 70x  test is like a ten minute mile for professional runners.  Anyone can do that (not me, but anyone who says he is a runner).  Closer to the three minutes-and-change mile is 2x per mm.  And yes, I'd say most real contenders have to be reliably below 4 minute miles these days, and most apos can do better than 2x per mm.  But at least you're in a zone that is acknowledged to be tough.

 

I doubt your 140 will give up anything at 280x, but you don't know till you try, and the full moon pic, while very nice to the eye, was not a color test.  Try to nail the limb at 280x.  Or a daytime branch in bright sun against blue sky.  If you're feeling nutso keep on pushing past  280.  

 

Greg N


  • CounterWeight and SkyHunter1 like this

#71 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 22 March 2019 - 10:40 AM

A 1/4 20 screw is more than enough to hold a scope.  There is an advantage in that a single bolt in center ring can adjust its angle to the tube.  If you screw in two screws tight it is the tube that will have to adjust to the rings.  My GT130 is held on to the Losmandy dovetail by two rings, each with one screw.  This is also true of the top rail.  In fact if your top rail has four screws and your bottom rings are held in by 4 screws you now have the potential for slight misalignments to be working in opposite directions.  

 

My 2c....

 

I'm assuming I understand you correctly, that you want more than one screw in each ring rather than the center screw.  

 

GN

Greg,

It's funny you should say that. Just last night I had my carpenter friend over to fix his computer and give him the rings for the modification. He said that adding more screws wouldn't really improve stability and he also mentioned the alignment issue as you did above. He also said the 2 screws were more than enough to hold the scope. In the end I decided to leave it as is with the 2 screws and the Losmandy plate. One screw in the center of each ring. Thanks so much for everyone's help in optimizing my setup. It seems very solid to me, but again, as you and my friend mentioned, the additional screws may do more harm than good. 

 

Regards,

Skyhunter1



#72 gnowellsct

gnowellsct

    Hubble

  • *****
  • Posts: 15963
  • Joined: 24 Jun 2009

Posted 22 March 2019 - 11:10 AM

Greg,

It's funny you should say that. Just last night I had my carpenter friend over to fix his computer and give him the rings for the modification. He said that adding more screws wouldn't really improve stability and he also mentioned the alignment issue as you did above. He also said the 2 screws were more than enough to hold the scope. In the end I decided to leave it as is with the 2 screws and the Losmandy plate. One screw in the center of each ring. Thanks so much for everyone's help in optimizing my setup. It seems very solid to me, but again, as you and my friend mentioned, the additional screws may do more harm than good. 

 

Regards,

Skyhunter1

That's a smart carpenter guy with an intuitive grasp of systems with which he is not familiar.  Those are really good kinds of people to know.  And I get kudos points for calling it first!

 

Greg N


  • SkyHunter1 likes this

#73 gnowellsct

gnowellsct

    Hubble

  • *****
  • Posts: 15963
  • Joined: 24 Jun 2009

Posted 22 March 2019 - 03:08 PM

In case you were wondering the load strength of a 1/4-20 screw is 1,049 lbs according to this chart.  and it's probably closer to 1,700 lbs because I as just reading the first group of numbers.  The McMaster stainless 1/4 20 screws are 70,000 PSI not 75,000 as in the second group of data but I think you get the picture.  It's a lot more than your 140 mm triplet.  The safety redundancy in your system is that you have two rings.  Each one by itself can support the tube and ten others like it with a large margin of safety.   I don't know what the *shearing* resistance is, but whatever force is sufficient to *shear* the refractor off its bolts will likely annihilate the tube and you with it.  I'm thinking you get hit by a Mack truck that has a thing about astronomers.

 

Greg N



#74 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1895
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 22 March 2019 - 05:46 PM

Glad you finally got it out, SkyHunter!  Im in the same boat here in upstate, NY.....its been just lousy out.  But, this weekend has a lot of potential so Im keeping my fingers crossed.  Love to get my triplet out too!  Not as big as yours though. :)

 

Post more pics when you can, love to see them!!!! 



#75 SkyHunter1

SkyHunter1

    Vostok 1

  • *****
  • topic starter
  • Posts: 175
  • Joined: 09 Nov 2017
  • Loc: Long Island NY

Posted 24 March 2019 - 07:08 PM

That's a smart carpenter guy with an intuitive grasp of systems with which he is not familiar.  Those are really good kinds of people to know.  And I get kudos points for calling it first!

 

Greg N

Greg, I give you full credit for calling it first :) I appreciate all the help you've provided and your input regarding proper testing for this scope. 

 

 

In case you were wondering the load strength of a 1/4-20 screw is 1,049 lbs according to this chart.  and it's probably closer to 1,700 lbs because I as just reading the first group of numbers.  The McMaster stainless 1/4 20 screws are 70,000 PSI not 75,000 as in the second group of data but I think you get the picture.  It's a lot more than your 140 mm triplet.  The safety redundancy in your system is that you have two rings.  Each one by itself can support the tube and ten others like it with a large margin of safety.   I don't know what the *shearing* resistance is, but whatever force is sufficient to *shear* the refactor off its bolts will likely annihilate the tube and you with it.  I'm thinking you get hit by a Mack truck that has a thing about astronomers.

 

Greg N

Hahahahahaha :) So it looks like I'm good to go so long as I stay away from truck drivers who got beat up for their lunch money by Carl Sagan as a child. Point noted...


  • gnowellsct likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics