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Any Interest in an 8" Al Travel Scope group build?

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#1 gatorengineer

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Posted 18 August 2013 - 02:50 PM

We have some very talented designers and alot of great ideas, any interest in an 8" travel scope group build. Thinking of something that could be waterjetted out of aluminum.. Would need to account for various focal lengths of primaries...

Seeing what people think.

#2 Mirzam

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Posted 18 August 2013 - 05:51 PM

I'll bite. Need to see some ideas though. How about a 1/2 ring UTA with two poles? Lawnmower blade style spider?

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#3 kfrederick

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Posted 18 August 2013 - 06:28 PM

Maybe Danny will do some 3d drawings Of some of the ideas . Maybe a scale of the James Web all folded up for launch then opens up . Just kidding

#4 Mirzam

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Posted 18 August 2013 - 06:32 PM

I'll add that f/5 is a good number for a small travel scope. Longer than this requires counterweighting. Shorter requires more sophisticated collimation tools, which add weight. Although you can use the tools as counterweights.

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#5 Pinbout

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Posted 18 August 2013 - 07:38 PM

Maybe Danny will do some 3d drawings Of some of the ideas . Maybe a scale of the James Web all folded up for launch then opens up . Just kidding


I could eve animate it and put it on youtube :lol:

#6 jwaldo

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Posted 18 August 2013 - 11:26 PM

I've doodled around a bit with a 6-8" all-aluminum travel dob a bit, never got beyond some half-done 3D models though...

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#7 Arjan

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Posted 19 August 2013 - 02:46 AM

If you want to save a bit more on weight, you could get rid of the focuser-side trunnion and replace it with a 1/2" or so axle?

#8 Pinbout

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Posted 19 August 2013 - 06:29 AM

Like a litescope

#9 kfrederick

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Posted 19 August 2013 - 11:57 AM

Because every part and every hole drilled can be done on the CNC Jet [If people wont ] And compound curves or anything that can be drawn can be made very accurate .003 . Go wild .Danny looks great your work You need a CHief . Hope you come down some time

#10 Arjan

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Posted 19 August 2013 - 01:40 PM

Yes, for example like Litescope or like Toshimi Taki

#11 gatorengineer

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Posted 19 August 2013 - 05:36 PM

was actually hoping to come up with an aluminum version of this in the 8" size... Jetted out of 0.25" aluminum and tig welded together..... maybe even anodized......

http://www.sumeriano...roducts/alkaid/

#12 polaraligned

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Posted 19 August 2013 - 07:38 PM

I would definitely be into a well designed 8" travelscope.
I can donate CNC mill time to the cause.
I like the sumerian optics scope, but think a single pole would be easier setting up. Now if we could design a telescoping pole that was stiff enough, that would be huge. I can't make the mirror myself, but would like a quality f/4 mirror. Maybe cellular if some amateur casters want to get into the game...

#13 Dave O

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Posted 19 August 2013 - 08:24 PM

Looks a lot like the scope shown by bertb, message #4495943 in this thread: http://www.cloudynig...&Board=atm&N...

Would aluminum be stiff enough?

Wonder how he did the trusses?

#14 Arjan

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Posted 20 August 2013 - 02:13 AM

was actually hoping to come up with an aluminum version of this in the 8" size... Jetted out of 0.25" aluminum and tig welded together..... maybe even anodized......

http://www.sumeriano...roducts/alkaid/


Ah! Nothing wrong with a Dutch design... :grin:

#15 Arjan

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Posted 20 August 2013 - 02:26 AM

Wonder how he did the trusses?

IMHO, trusses are usually over-designed, there's a lot of weight to save. A German design even uses lightweigth foldable rules, 8 of them apparently made it stiff enough.

#16 Pinbout

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Posted 20 August 2013 - 05:59 AM

and then there's teeter's design

http://www.youtube.c...h?v=2kCitl8BHUM

rob contacted mr.sumerian but mr. sumerian didn't want to license his designs. whatever.

#17 Dave O

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Posted 20 August 2013 - 09:12 AM

Wonder how he did the trusses?

IMHO, trusses are usually over-designed, there's a lot of weight to save. A German design even uses lightweigth foldable rules, 8 of them apparently made it stiff enough.


My goodness! I'd have never even considered that! If those folding rules truly are stiff enough to support the upper cage, I think that they would be a tough choice to beat as far as convenience for packing is concerned? Surely the design could be improved upon -- but perhaps there is no need? Certainly easy enough to procure. Thanks for sharing that bit of intel. :)

#18 Pinbout

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Posted 20 August 2013 - 09:23 AM

Certainly easy enough to procure.


and if you mess up measuring their lengths... :foreheadslap:

#19 kfrederick

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Posted 20 August 2013 - 11:00 AM

One thought is interlocking plates to build the tube they could be hinged so each is short . When interlocked should be strong optical tube . Or tripod legs they slide into them self and make short poles . Just ideas .

#20 Chriske

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Posted 20 August 2013 - 11:07 AM

Wonder how he did the trusses?

IMHO, trusses are usually over-designed, there's a lot of weight to save. A German design even uses lightweigth foldable rules, 8 of them apparently made it stiff enough.


We tested the foldable rules. It was not stiff enough. While rotating the rocker the scope flexed quit a lot and did not return to its 'starting point', as expected.

#21 Arjan

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Posted 20 August 2013 - 11:14 AM

Yeah, but there's a lot of room between 20mm alu tubes and el-cheapo rules...

The hysteresis apparently is not due to lack of stiffness? Maybe the mounting on the ends does it.

#22 Chriske

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Posted 20 August 2013 - 12:13 PM

Hi,

dunno were Danny is located, but maybe he could make these drawings using Imperial I could redo them using metric values...? Just a thought... :cool:

Hope it helps starting this project.

#23 Pinbout

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Posted 20 August 2013 - 01:06 PM

dunno were Danny is located,



I right here... :lol:

take this *.txt file and rename it *.kmz and put it in google earth

[wow I renamed the *.kmz to a txt file uploaded it as usual and something turned it into a zip file containing the a *.kmz file with all the locations saved. :foreheadslap:]

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#24 Arjan

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Posted 20 August 2013 - 02:06 PM

rob contacted mr.sumerian but mr. sumerian didn't want to license his designs. whatever.


You could go to the source: Strock 250
Here you will find what you need. Maybe not exactly the same but the similarity is obvious...

Edit: At closer look, the Sumerian is a much more elaborated design, where everything has been done to minimize the collapsed size. IMHO this seems to come at the cost of a more complicated setup. Probably a matter of taste, but the one holiday experience with my boxed dob gave me second thoughts about that.

#25 Pinbout

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Posted 20 August 2013 - 02:27 PM

rob contacted mr.sumerian but mr. sumerian didn't want to license his designs. whatever.


You could go to the source: Strock 250
Here you will find drawings in PDF. Maybe not exactly the same but the similarity is obvious...


that's not to a known scale. I have the pdf and the hand drawings. I scaled it up, but there are so many details not in the drawing, which would have to be R&D'd if thats what your starting with.

If you licsense Mr. Sumerian's designs everything is already thought out, less design work. after the first run you could ask for the rights to modify the design.






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