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Micro Very Large Binocular Telescope Project

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#1 Fivemileshigh

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Posted 12 May 2021 - 07:55 AM

So, I've been hashing ideas for a large binoscope for a few years, but recently two things happened to give the project a huge jolt forward:

1. I gave up on the idea of having it portable
2. I found a suitable location to build it.

I'm going to start this thread as a place to have my ideas critiqued and improved upon by the community that has given me so much to be since I started astronomy, I also will use it as extra motivation to finish it. I estimate 2-3 years to complete.

As much as possible, components will be commercially made, including the optics. I'm looking to reinvent as few wheels as possible.

I haven't finalized the specs yet, the primaries will be more than 30 but no more than 50in. I made a 12:1 model for my desk. In the photos, Luke Skywalker is 6" tall, I am 6', and the model is calculated around 40" f/3.


IMG_4135.JPG

Edited by Fivemileshigh, 12 May 2021 - 08:04 AM.


#2 Fivemileshigh

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Posted 12 May 2021 - 07:57 AM

Closer to horizontal:

IMG_4136.JPG

#3 tjschultz2011

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Posted 12 May 2021 - 09:14 AM

This is a formal offer to come test it out once you have it up and running lol. You should incorporate a seat into the build and motorize the whole set up including the seat. I remember seeing a post about it a while back and it looked like the coolest thing ever. 

 

https://www.cloudyni...rean-binoscope/


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#4 TOMDEY

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Posted 12 May 2021 - 09:30 AM

Very good and off to a great start! I'd say your most significant challenge will be ~Project Management~ >>>

 

I discovered that grandiose projects can quickly turn months into years, years into decades, and kilobucks into the cost of a house or two. A 40-inch True Binoscope from initial concept to successfully-operational in 2-3 years (24-36 months) is extremely ambitious, probably doable, but would realistically require full-time engagement, plenty of sub-contracting, plenty of $$$, lots of project-coordination experience, and full-time obsessive commitment to that project... and essentially nothing else, for the duration. Friends and I have indeed taken on projects of that scale --- most running around a decade and landing right around double the original budget estimate.

 

I bought and sat on two 29-inch mirrors for a long time and finally backed off on my aspirations, deciding to build a monoscope first. I then enjoyed that for a long time and eventually graduated up to the 36-inch monoscope shown in my dome here >>> And yes, I have indeed considered maybe, just maybe... expanding that to a 36-inch Binoscope (where your nominal resides) or maybe a 50-inch monoscope.

 

I'd recommend in your path forward, to prudently include in your schedule --- maybe on the first day of each month, to seriously revisit the question, "Am I being realistic, manic --- or hopefully/necessarily --- both?!" It's what I call ~Scheduled Soul-Searching~. That will keep the project rolling forward or prudently-shelved. Either decision is honorable. [This approach to funded projects on a schedule is actually how the government handles aerospace programs --- contractors have to periodically meet/report/present milestones and budget or else risk termination or renegotiation. I lived in that environment for my entire career and found that approach even necessary to successfully accomplish personal hobby projects!]    Tom

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  • 135 Tom's 24-foot dome opening wide enough for 36-inch bino or 50-inch mono.jpg

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#5 Fivemileshigh

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Posted 12 May 2021 - 12:17 PM

This is a formal offer to come test it out once you have it up and running lol. You should incorporate a seat into the build and motorize the whole set up including the seat. I remember seeing a post about it a while back and it looked like the coolest thing ever. 
 
https://www.cloudyni...rean-binoscope/

 
I've seen that, it's pretty cool. A 2 person platform is on the to do list, after first light. Ladders will be essential until then.
 

Very good and off to a great start! I'd say your most significant challenge will be ~Project Management~ >>>
 
I discovered that grandiose projects can quickly turn months into years, years into decades, and kilobucks into the cost of a house or two. A 40-inch True Binoscope from initial concept to successfully-operational in 2-3 years (24-36 months) is extremely ambitious, probably doable, but would realistically require full-time engagement, plenty of sub-contracting, plenty of $$$, lots of project-coordination experience, and full-time obsessive commitment to that project... and essentially nothing else, for the duration. Friends and I have indeed taken on projects of that scale --- most running around a decade and landing right around double the original budget estimate.


I'm indeed not discount the possibility of a certain streak of manic obsessiveness, maybe that'll be the fuel required. I have the place, I know my way around CNC machines, the people upstair green-lighted the project, the people downstairs don't get a say, so, I don't think I'm missing much. Fingers are firmly crossed.

#6 PETER DREW

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Posted 12 May 2021 - 01:56 PM

I'd be up for doing something similar if I could convince myself that the law of diminishing returns might make the expense and effort  worth it.  I have built many refracting and reflecting binoscopes and solved, for my liking, the issues that present themselves.  I have stalled at 12" F3.5 despite seriously considering something larger, despite modern fast focal ratios, the focal length of very large binoscopes is still considerable.  Ergonomics aside, a point is reached where the nicety of binocular vision becomes less appealing due to the ever decreasing actual field of view.  Perhaps the opportunity to have a look through a very large one might change my outlook.  If I took the plunge and bought the optics I wouldn't expect the construction to take more than a year albeit at nearly full time.  At my age I have to push projects through in good time!


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#7 Bob4BVM

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Posted 12 May 2021 - 02:39 PM

I can relate to Peter's statement:  "At my age I have to push projects through in good time!"

 

SO I am pressing on with mine, a baby version of what you have planned.    I find alot of enjoyment in letting my creative juices digest and solve problems as they come along in my build, a nice relaxed approach compared to my professional working life.  But i am also cognizant of the fact that i do not have unlimited years on this planet to use it, so i am trying to keep busy on it. In that light i wish i had started it a bit earlier.

 

re the above comment on the Korean binoscope, if mine were just a bit larger i would seriously consider making it a ride-aboard like that one. For the magnitude and scale of what you are talking about, i would definitely include a pilot's seat. It's the best way to overcome the FL / observing positions issue, and almost a trivial addition to a scope with the kind of mass you are considering.

 

Looking forward to see where you go with this !

 

CS

Bob 


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#8 PrestonE

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Posted 12 May 2021 - 03:09 PM

I helped make many machined parts for a friends 24 inch Binoscope...over 15 years ago...

 

It has seen first light at TSP, though I do not remember the year...

 

However, there were So Many small and large changes that needed to be made

that to this day it is still not finished...

 

The Design phase for the CAD alone for a full scale model rendering every part and

calculating balance would likely take the better part of 3 to 6 months depending on your

skill level...and that does not include FEA studys...

 

As Tomdey says above...This Would Be a Full Time Project at the Very least to finish it

in 2 to 3 years...

 

I built a 20inch RC doing the design and machining everything myself, and it took most of

24 months...out of pocket cost 25K$ and 4000 plus hours.

 

My estimate for an out of pocket expence if purchasing most things and having machining

done for what is not available would be just south of 150k US$...much of that for the mirrors.

 

It will be interesting to see if this thread is here in 2 plus years...Good Luck...

 

Best Regards,

 

Preston


Edited by PrestonE, 12 May 2021 - 03:10 PM.

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#9 Fivemileshigh

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Posted 12 May 2021 - 04:43 PM

Thanks for all the encouraging words guys!

 

I helped make many machined parts for a friends 24 inch Binoscope...over 15 years ago...
 
It has seen first light at TSP, though I do not remember the year...
 
However, there were So Many small and large changes that needed to be made
that to this day it is still not finished...


Well, none of my other projects are completely finished, there is always something that can be improved or changed, I don't think this one will be any different laugh.gif
 

The Design phase for the CAD alone for a full scale model rendering every part and
calculating balance would likely take the better part of 3 to 6 months depending on your
skill level...and that does not include FEA studys...


It depends to what level of detail I want to go into. For my 16" travel scope, I went really deep with the analysis because the targets were very difficult to achieve, in view of the maximum permissible weight. This one is going to have much more relaxed requirements because it is never going to move. I'm basically going to overbuild and reinforce everything in sight. It will be assembled on-site, so it will never move. I estimate 1200lbs for the 40".
 

It will be interesting to see if this thread is here in 2 plus years...Good Luck...
 
Best Regards,
 
Preston


Well, the thread sure will be, it'll be interesting to see if the scope is going to be lol.gif

 

Thanks!



#10 PETER DREW

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Posted 13 May 2021 - 03:49 AM

There is a vast difference in timescales between making these things for a living or as a hobby.  I've done both but as I'm now "retired" it's back to hobby pace. 



#11 clivemilne

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Posted 13 May 2021 - 04:50 AM

So, I've been hashing ideas for a large binoscope for a few years, but recently two things happened to give the project a huge jolt forward:

I haven't finalized the specs yet, the primaries will be more than 30 but no more than 50in.

 

I'd be up for doing something similar if I could convince myself that the law of diminishing returns might make the expense and effort  worth it. 

Well, there would be some degree of upside if a couple of us were building roughly the same instrument.

 

For example, ordering a custom secondary mirror designed for a non-standard fold angle is a very different proposition to placing an order for 6 of them.

 

Likewise, coating a single secondary mirror with the dielectric layer thickness optimized for non standard angle of incidence would be an expensive proposition.  It becomes a whole lot more affordable if there were 8 big flats in the chamber at the same time.

 

CNC machining of the opto-mechanical support structure  also benefits hugely from standardizing fixtures and tool paths.

 

There is also the benefit of having others help drive the process along...  

 

 

Anyway,

Where I am at is that I have already locked in 40" f3.75  (first optic should be finished later this year.)

 

I have a pair of 20" f3.75" primaries that will be used as a path finder instrument.   

First make a 20" f3.75 monocular as a test mule for the compliant merger-pivoting cell.

2nd,  upgrade it to a bino.

3rd,  build a 40" mono.

4th upgrade it to a bino.

 

The idea is to add one significant variable (or innovation) at a time rather than doing the full greasy balloon squeeze all in one go.

 

Well, that's what I am doing, for what it is worth.


Edited by clivemilne, 13 May 2021 - 04:50 AM.

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#12 Fivemileshigh

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Posted 13 May 2021 - 11:19 AM

For example, ordering a custom secondary mirror designed for a non-standard fold angle is a very different proposition to placing an order for 6 of them.

 

Likewise, coating a single secondary mirror with the dielectric layer thickness optimized for non standard angle of incidence would be an expensive proposition.  It becomes a whole lot more affordable if there were 8 big flats in the chamber at the same time.

 

CNC machining of the opto-mechanical support structure  also benefits hugely from standardizing fixtures and tool paths.

 

There is also the benefit of having others help drive the process along...  

I have ruled out a low rider for now because putting the tertiary inside the Paracorr (which is what I'm doing) will be difficult enough to do precisely enough at 45deg, when the entrance and exit lenses are at right angles to each other. An off-square design gives me a headache just thinking about it, besides folding it enough to make a real difference is going to require a huge secondary.



#13 eroyer

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Posted 13 May 2021 - 11:48 AM


 

Anyway,

Where I am at is that I have already locked in 40" f3.75  (first optic should be finished later this year.)

 

I haven't finalized the specs yet, the primaries will be more than 30 but no more than 50in. I made a 12:1 model for my desk. In the photos, Luke Skywalker is 6" tall, I am 6', and the model is calculated around 40" f/3.
 

Thanks guys, when someone tells me I'm crazy building a 24" binoscope, I can reply that compared to other builders I'm quite reasonable.

 


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#14 Bob4BVM

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Posted 13 May 2021 - 01:26 PM

Thanks guys, when someone tells me I'm crazy building a 24" binoscope, I can reply that compared to other builders I'm quite reasonable.

Ha, Yes !!!

So my 17.5 should be a cakewalk !

 

 3 years in, that has not proven to be the case

... welcome to the real world ?

...or maybe they get easier as they get bigger ?

 

smile.gif

Bob


Edited by Bob4BVM, 13 May 2021 - 01:28 PM.


#15 TOMDEY

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Posted 13 May 2021 - 03:15 PM

Ahhh... the old ~make/buy~ conundrum...

 

I got around the difficulties by --- just buying this modest little 16-inch Binoscope, and buying the roll-out shed. But I claim credit for attaching the store-bought ramp tops to a couple of 2x10s. I then rewarded myself by --- observing a lot! When friends drop by... I act like I built the whole thing myself. A man's work is never done.    Tom

 

~A "Make or Buy" is a business model that will help managers to take a decision either to make a product or to buy a product. The model will analyze the relative cost for each option and recomend the best option that will achieve the Best Value for the money.~

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#16 Bob4BVM

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Posted 13 May 2021 - 03:49 PM

Sure Tom but choices narrow fast above 16"...

He's talking something up to 50", don't think too many of those in astro market

Of course he also mentions six figures, so maybe if we up the budget just a bit he could buy one of these:

https://www.lbto.org/

 

smile.gif


Edited by Bob4BVM, 13 May 2021 - 03:50 PM.


#17 eyeoftexas

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Posted 13 May 2021 - 08:33 PM

Of course he also mentions six figures, so maybe if we up the budget just a bit he could buy one of these:

 

Heck, if he'll go for it I'll even chip in a dollar!  watching.gif



#18 Fivemileshigh

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Posted 15 May 2021 - 07:24 AM

Some light reading for the weekend, and every weekend from now on lol.gif

 

IMG_4178.JPG


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#19 PETER DREW

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Posted 16 May 2021 - 02:11 PM

Referring to the image in #2, I think I would be tempted to pivot the OTA at the point where the model touches the ground.  Elevation could be controlled via automotive gas struts connected somewhere convenient along the main body.  The whole unit could be mounted, including the observer on a large turntable for azimuth rotation.  The observer would be on some form of hydraulic lift.

The principle would be similar to the Lord Rosse 72" but having the advantage of 360 degree rotation.  No pressing need to achieve a vertical orientation as most objects reach a more ergonomically favourable position sooner or later.


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#20 Fivemileshigh

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Posted 16 May 2021 - 06:50 PM

Referring to the image in #2, I think I would be tempted to pivot the OTA at the point where the model touches the ground.  Elevation could be controlled via automotive gas struts connected somewhere convenient along the main body.  The whole unit could be mounted, including the observer on a large turntable for azimuth rotation.  The observer would be on some form of hydraulic lift.

The temptations are many indeed :) If this project is ever going to see the light of day, I have to reinvent as few wheels as possible, so I think I'll stick with a traditional dobsonian layout. 

 

And yes, some sort of lifting observation platform is in the cards.



#21 PETER DREW

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Posted 17 May 2021 - 04:43 AM

The advantage of the "Rosse model" is that the heaviest portion of the construction is attached to its base, greatly improving its stability.


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#22 Fivemileshigh

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Posted 17 May 2021 - 06:10 AM

Yes it would, however the control algorithm would be tough as the scope is not rotating about its CG. The control forces would go from large positive to zero to negative with a null zone.

Edited by Fivemileshigh, 17 May 2021 - 06:11 AM.


#23 PETER DREW

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Posted 17 May 2021 - 02:26 PM

Wouldn't the gas struts help with that?.  These are just initial musings, I've little practical experience at this size level although I did build the tube assembly for a 42" Newtonian.



#24 Bob4BVM

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Posted 17 May 2021 - 08:01 PM

Yes it would, however the control algorithm would be tough as the scope is not rotating about its CG. The control forces would go from large positive to zero to negative with a null zone.

I'd think a fairly low alt pivot point would solve all that, making the scope a bit tail-heavy would help stabilize the whole thing. Control could be pretty simple, the thing is not moving that fast...

Simply sizing the motor and gearing with enough safety factor to easily handle the inertial loads you are contemplating. 

The motion control would seem to me to be the easiest part of this monster, trivial compared to many other issues present in a binoscope this size.

CS

Bob



#25 Fivemileshigh

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Posted 17 May 2021 - 08:25 PM

Not going to happen guys.


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