Jump to content


Photo

The future of mounts--any thoughts?

  • Please log in to reply
30 replies to this topic

#1 mistyridge

mistyridge

    Gemini

  • *****
  • Posts: 3036
  • Joined: 28 Oct 2005
  • Loc: Loomis, CA

Posted 14 February 2011 - 06:02 PM

I just finished skimming the latest issue of ATT and was struck by what I see as a trend in mounts. Spcifically self aligning technology such as the new Celestron Prodigy and Mead Lightswitch may lead to larger capacity high end mounts suitable for AP. Will GEMs become obsolete? Will having to do polar alignment be a thing of the past? Will we see portable self aligning harmonic drive mounts, light weight with no counter weights?

#2 Astrojensen

Astrojensen

    Fly Me to the Moon

  • *****
  • Posts: 5454
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 14 February 2011 - 06:24 PM

Spcifically self aligning technology such as the new Celestron Prodigy and Mead Lightswitch may lead to larger capacity high end mounts suitable for AP.



Why would these small self-aligning mounts lead to big mounts suitable for astrophotography? They are made for very different markets.

Will having to do polar alignment be a thing of the past?


Not if you want to do long-exposure photography with no field rotation, but I think there's a good chance that mounts will be developed that can do it themselves with very, VERY high accuracy. All it would take was some motors on the altitude and azimut adjustments on a GEM, a CCD camera and a computer that could talk with the camera, the mount and the adjustment motors and then run an automated drift alignment procedure. Given the sensitivity of the CCD, it could probably be done in a few minutes.

Will we see portable self aligning harmonic drive mounts, light weight with no counter weights?



Interesting. Maybe, I'd say, but not likely in the next five years. Still too expensive.

Will GEMs become obsolete?



Hardly.


Clear skies!
Thomas, Denmark

#3 Frank Boreas

Frank Boreas

    Explorer 1

  • -----
  • Posts: 61
  • Joined: 02 Nov 2010
  • Loc: Northern Wisconsin

Posted 14 February 2011 - 06:26 PM

Did astrophotography make eyepieces obsolete?

Did goto make starhopping a thing of the past?

For some yes, but I suspect there will always be some like me that enjoy simple setups and observing au natural.

#4 skybsd

skybsd

    Skylab

  • *****
  • Posts: 4281
  • Joined: 01 Feb 2008

Posted 14 February 2011 - 06:42 PM

Reminds me of the kind of stuff my Dad told me they were told back in the '60s - good thing he didn't hold his breadth waiting for those personal hovercrafts :lol:

Regards,

skybsd

#5 EJN

EJN

    Vanguard

  • *****
  • Posts: 2261
  • Joined: 01 Nov 2005
  • Loc: 53 miles west of Venus

Posted 14 February 2011 - 07:00 PM

In the future, as mental powers improve, people will learn to
levitate their telescopes using psychic energy and mounts will
be unnecessary.

#6 tjugo

tjugo

    Apollo

  • -----
  • Posts: 1013
  • Joined: 06 Nov 2007

Posted 14 February 2011 - 10:21 PM

Some of the newer mounts (ASA) don't need to be autoguide... At least I expect in the next 5 years a mount in the class of CGEM/Atlas that won't need to be autoguided...

Cheers,

Jose

#7 mistyridge

mistyridge

    Gemini

  • *****
  • Posts: 3036
  • Joined: 28 Oct 2005
  • Loc: Loomis, CA

Posted 15 February 2011 - 02:37 AM

I guess we are doomed to be stuck in the past. Look to China for innovation. :shrug:

#8 Chris Lyons

Chris Lyons

    Explorer 1

  • -----
  • Posts: 51
  • Joined: 28 Dec 2009
  • Loc: Baltimore

Posted 15 February 2011 - 03:33 AM

Hi Jose!
My A.S.A. DDM-85 does need to be autoguided beyond
around 30-40 mins but that's probably a result
of flexure in my OTA rings. Getting rid of that
is proving to be a bear!
The DDM-85 could probably go without guiding for
hours if the flexure issue was banished but how
long in reality I couldn't say. Not yet anyhow!
This direct drive tech is mind blowing and there
is no going back now to anything less.
The future of mount tech is BRIGHT!
Chris Lyons.

#9 Waxing Gibbous

Waxing Gibbous

    Viking 1

  • -----
  • Posts: 541
  • Joined: 19 Nov 2010
  • Loc: Victoria, Australia

Posted 15 February 2011 - 08:37 AM

Built-in guidscopes with both spectroscopic and pattern recognition, linked of course to the mount's PEC software?

#10 Ad Astra

Ad Astra

    Viking 1

  • *****
  • Posts: 530
  • Joined: 12 May 2010
  • Loc: Riverside Co., California

Posted 15 February 2011 - 06:29 PM

I'd love to see a titanium edition of something like the AP-900 mount. That mount disassembles into two hefty pieces, a titanium edition would be very strong, and very light weight as well.

Just a thought!!

Dan

#11 BPO

BPO

    Ranger 4

  • -----
  • Posts: 369
  • Joined: 23 Feb 2010
  • Loc: South Island, NZ

Posted 15 February 2011 - 06:38 PM

Chris, I've been communicating with a university that operates a few DDM-85 mounts and they were limited to approximately 45 minute unguided exposures due to OTA truss rigidity problems, which they are still attempting to resolve.

However, another user solved his flexure conundrum by replacing all stock bolts and fasteners with much higher quality ones, and is now able to achieve in excess of 90 minute unguided exposures, so it sounds as if you're on the right track with your problem solving quest.

Good luck, you have a heck of a mount there.

#12 avarakin

avarakin

    Surveyor 1

  • *****
  • Posts: 1884
  • Joined: 13 Jul 2009
  • Loc: Parsippany NJ, USA

Posted 15 February 2011 - 08:42 PM

How about Alt/Az mount with field de-rotator coming as part of the mount and controlled by main computer? I never used field de-rotator, but based on a mental experiment, I think that field de-rotator needs to have variable speed depending on point in the sky it is pointing to. Thus it needs to be controlled by main computer which drives other 2 motors. Once you have 3 axis controlled by a computer, there is no need to polar align such mount.
Advantages of such mount would be:
1. no need to do polar alignment, computer would just move all motors based on result of 2 or 3 star alignment procedure
2. since it is Alt/Az, there is no need for counterweight
3. A separate kit can be manufactured which fits a regular dob

Based on all this, a 24" amateur astrograph becomes a reality!
GEM is dead, long live Dob!

Alex

#13 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5714
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 15 February 2011 - 09:51 PM

Meade already had such a field derotator on their larger LX200GPS models almost ten years ago.. it is as you describe, the alt-az computer also drove the motor on the derotator.

The famous Mel Bartels scope.exe DOS-based scope drive also has a provision for driving a field derotator in addition to the alt and az motors.

#14 Astrojensen

Astrojensen

    Fly Me to the Moon

  • *****
  • Posts: 5454
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 16 February 2011 - 04:38 AM

This Danish mount is an altaz with a innovative field rotator that rotates the entire telescope instead of just the camera. Has been tested by a Danish imager and the prototype worked almost flawlessly. I've seen it in person, it's rugged and will easily carry a TEC 140. There's also a bigger mount that will carry a much larger scope.

http://shop.trackthe...t.asp?product=4

http://trackthestars....html?task=view


Clear skies!
Thomas, Denmark

#15 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 44725
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 16 February 2011 - 05:06 AM

I'd love to see a titanium edition of something like the AP-900 mount. That mount disassembles into two hefty pieces, a titanium edition would be very strong, and very light weight as well.

Just a thought!!

Dan


Titanium is a good aterial when strength is important but strength is not important in a mount. The difference between strength and stiffness is important, strength is how much force it takes to fail the part, stiffness is how much it moves under a given force. What is important in a telescope mount is stiffness, that is measured by Young's modulus, if you pull on a 10 inch long, 1 square inch area with say 20,000 lbs, how far does it move??

There are three metals that are worth considering, steel, titanium and aluminum. What is interesting about these three materials is they all have essentially the same "specific stiffness", i.e. how much force will it take to deform 1 pound of each material, made into a piece 1 foot long, 0.002 inches? It takes about the same force for all three...

So what it turns out is that for equal weight parts, if one can take advantage of the geometric advantages that increase stiffness, then aluminum is generally the best choice. If one is constrained to specific dimensions, then steel is the better choice.

As an example, if the question is: If I have 2 pounds of material and I want the stiffest tripod leg that is 40 inches long, then aluminum is the material of choice. On the other hand, if I have 2 pounds of material and I want the stiffest tripod leg that is 40 inches long AND 1.75 inches in diameter, then steel is a somewhat better choice.

Jon

#16 alpal

alpal

    Soyuz

  • -----
  • Posts: 3694
  • Joined: 15 Jun 2009
  • Loc: Melbourne Australia.

Posted 16 February 2011 - 05:39 AM

I am hoping the EQ8 will be a good mount.
I might buy one if they are any good.
see youtube video:

http://www.youtube.c...6WLerTKZg#at=18

#17 Astrojensen

Astrojensen

    Fly Me to the Moon

  • *****
  • Posts: 5454
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 16 February 2011 - 06:58 AM

As an example, if the question is: If I have 2 pounds of material and I want the stiffest tripod leg that is 40 inches long, then aluminum is the material of choice. On the other hand, if I have 2 pounds of material and I want the stiffest tripod leg that is 40 inches long AND 1.75 inches in diameter, then steel is a somewhat better choice.



And if I have to build it myself in my small shop, then wood is the best choice! :lol:

Nice little lecture, Jon.


Clear skies!
Thomas, Denmark

#18 rjsc2000

rjsc2000

    Mariner 2

  • -----
  • Posts: 214
  • Joined: 21 Sep 2006
  • Loc: Portugal

Posted 16 February 2011 - 08:18 AM

What about carbon? As seen in telescopes tubes made of it?

#19 Astrojensen

Astrojensen

    Fly Me to the Moon

  • *****
  • Posts: 5454
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 16 February 2011 - 08:56 AM

Carbon fiber materials can certainly be used for some parts of a mount, but it is not a material for the average ATM, for sure. Carbon dust must be kept far away from any electric tools, for example, or they will short circuit in a few moments after getting the carbon dust inside.

I am not sure if carbon materials can be die cast, like aluminum, so that you could cast axle housings, for example.


Clear skies!
Thomas, Denmark

#20 Peter Glus

Peter Glus

    Mariner 2

  • *****
  • Posts: 218
  • Joined: 08 May 2006

Posted 16 February 2011 - 10:21 PM

harmonic gears....thats the best invention yet for mounts

#21 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5714
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 16 February 2011 - 10:49 PM

pity harmonic gearboxes are eye-poppingly expensive (and monopolized by a single manufacturer).

i was thinking of doing some DIY experimentation but even surplus harmonic gearboxes cost an arm and a leg on ebay.

#22 BPO

BPO

    Ranger 4

  • -----
  • Posts: 369
  • Joined: 23 Feb 2010
  • Loc: South Island, NZ

Posted 17 February 2011 - 12:53 AM

After comparing current harmonic drive based mounts with the available direct drive models, the decision seemed easy to make.

#23 gdd

gdd

    Surveyor 1

  • -----
  • Posts: 1707
  • Joined: 23 Nov 2005
  • Loc: Lynnwood, WA (N/O Seattle)

Posted 17 February 2011 - 10:52 AM

Will having to do polar alignment be a thing of the past? Will we see portable self aligning harmonic drive mounts



Currently even the self aligning mounts take their best shot at aligning and then rely on autoguiding to compensate for alignment errors. Will the future have continous aligning mounts, where the autoguider feeds senses drift and makes corrections to the polar alignment to reduce further drift? Will it also sense disagreement with the star maps and make on-the-fly modelling corrections?

Gale

#24 Chris Lyons

Chris Lyons

    Explorer 1

  • -----
  • Posts: 51
  • Joined: 28 Dec 2009
  • Loc: Baltimore

Posted 17 February 2011 - 04:52 PM

Howdy BPO. Yep I know what you
mean about the choice!
Those Chronos mounts just look
awesome and the whole no CW and
no meridian flip thing is a real
selling point but there was no
way I could justify the price at
the time ( or now!! ) plus there
was a good reason to go with the
A.S.A. DDM aside from the direct
drive no PE deal -- the guys at
my company are direct drive and
PID demons so I knew there would
be immediate support! :)
And the DDM looks very cool ( but
so does the Chronos!! Decisions! )
You know you have the right mount
when all your tracking problems
are solely caused by flexure in
the scope and rings!
With no guide scope and other junk
hanging off it things are simpler
and I get excellent unguided times.
The PE is non existent so that's
good. :D
The only downsize if you like to
these new top line mounts is the
learning curve can be steep for
people who aren't used to it.
So I guess it comes down to how
seriously you take the hobby.
Chris

#25 Hikari

Hikari

    Viking 1

  • *****
  • Posts: 940
  • Joined: 05 Jan 2011
  • Loc: Maine, USA

Posted 17 February 2011 - 06:47 PM

One day they will make mounts that can do more than just go around in circles.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics