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10"F/4.6 MakCass with 23% C.O.

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#26 Astrojensen

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Posted 23 July 2012 - 02:02 PM

long cool down and after that a stable image, is far better then turbulences all night in a open Tube !!!!



I have a carbon fiber C8. It never cools down and has turbulent images all night...! :doah: :tonofbricks:


Clear skies!
Thomas, Denmark

#27 Chris_H

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Posted 23 July 2012 - 03:30 PM

I hear you, Thomas. A "long cool down and after that a stable image" doesn't work when the darn thing NEVER cools down ;) My old 180MAK was like that - and this is a 10"!

Anyway, it will be interesting to see what you come up with Markus! :D

#28 Astrojensen

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Posted 24 July 2012 - 03:04 AM

There's no doubt the feat can be pulled off, making a 10" mak with relatively fast cooldown, that is. A-P did it, as far as all the reviews go. I am not sure I've seen a review of any Aries maksutovs.

It is a mystery to me why a $1000 C8 doesn't come with a cooling fan, while a $400 8" dobsonian does. That just doesn't make sense.


Clear skies!
Thomas, Denmark

#29 APM M.Ludes

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Posted 24 July 2012 - 06:41 AM

Hi Thomas

is your 8" scope build like a modern fast cool down telescope should be build ? No, everything is done on it that it never cools down :-)

#30 EddWen

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Posted 24 July 2012 - 11:21 AM

Markus and Matthias recently built me a 400mm f/10 Rumak.

It has an open back tube with 3 fans. The tube has venting ports just behind the meniscus. The Astro-Sital mirror is polished on the back side for good heat transfer.

The scope has an internal heater for the meniscus which I've not had to use because it is dry in Arizona.

Cool down has not been a problem. I roll of the roof of the observatory when the Sun sets, point the scope up, switch on the fans and go have supper. An hour or so later, the scope is ready to play.

Some of this is due to our location in the high country of central Arizona. We have a rapid drop from daytime temperatures until about 9:30 – 10:00 pm. The rest of the night has a rather mild decline in air temperature. Also, the inside temperature of the observatory does not reach the outside air temperature as it is insulated.

When I considered getting the scope, I originally planned for either air-conditioning the observatory to keep it near night time temperatures, or building a mirror cooling system using Peltier devices to cool it more rapidly to ambient conditions. So far, I haven't done either. I may do the latter just for fun, as I think it cool.

I will make a thread about the scope when I have a chance. Too many hobbies, although retired.

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#31 Astrojensen

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Posted 24 July 2012 - 01:39 PM

is your 8" scope build like a modern fast cool down telescope should be build ? No, everything is done on it that it never cools down :-)



Precisely my point.

Why do they insist on doing it the wrong way? Haven't they learned anything in the last 40 years? I myself have thought of asking someone to machine a new tube for the optics, as the optics themselves are very good on this particular C8. It is very sharp and bright, but all the tube seeing almost always limit its performance. On those rare evenings when the seeing is perfect and the temperature stable and the tube is thermally stable, I've been able to use 800x on it on double stars with no image breakdown and well over 1000x on planetary nebulae.


Clear skies!
Thomas, Denmark

#32 contedracula

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Posted 14 September 2012 - 07:20 AM

Hello Markus,
have you good news about the project?

Seems to be a RR of Planetary Mirror Telecope, can you tell me the progress?

Thanks
Gianluca

#33 Sarkikos

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Posted 14 September 2012 - 08:19 AM

I wonder how this would compare to my 10" f/4.8 Newt which is already running at 23% CO? :thinking:

:grin:
Mike

#34 Sarkikos

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Posted 14 September 2012 - 08:24 AM

A maximum weight of only 29 to 30 lbs for a 10" Mak is very impressive. :waytogo:

My 10" Newt solid-tube OTA is about 39 lbs with rings and balancing weights. :tonofbricks:

Mike

#35 Sarkikos

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Posted 14 September 2012 - 08:32 AM

Thomas,

Why do they insist on doing it the wrong way? Haven't they learned anything in the last 40 years? I myself have thought of asking someone to machine a new tube for the optics, as the optics themselves are very good on this particular C8. It is very sharp and bright, but all the tube seeing almost always limit its performance.


I have a 6" Rumak. It takes longer to acclimate than my 10" Newt which does have a fan for the primary mirror. I suppose I could take the Rumak apart and drill holes along the meniscus for venting. But I'm reluctant to disassemble a Mak. I've never done it.

My 90mm Mak has a flippable secondary. Not a good design IMO, but it does allow me to keep one of the ports open for quicker cool-down and thermal adjustment during the night. I've covered the open port with screen to keep the bugs out. Now, how difficult would it be to design Maks with large vent holes with protective screening at optimum locations to allow acclimation, and have slidable covers built-in that can completely cover the holes if needed?

However, I take my Newts apart all the time for upgrades and tinkering. Easy sneezy. I've already drilled vent holes above the upper edge of the primary in my 8" f/6 Dob and installed a baffle above the holes to help direct rising warm air out of the vent holes. I'm thinking about doing the same thing for my 10" f/4.8. Nothing to it.

Mike

#36 contedracula

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Posted 14 September 2012 - 06:32 PM

I've C14HD and becames in cool down about 3 hours!!!!
The MN78 with one rear fan, only 15 minutes

Gianluca

#37 EFT

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Posted 15 September 2012 - 09:41 AM

I've C14HD and becames in cool down about 3 hours!!!!
The MN78 with one rear fan, only 15 minutes

Gianluca


There are fan solutions for the Edge HD scopes.



#38 Sarkikos

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Posted 15 September 2012 - 09:53 AM

Pretty much what I said should be done with these Maks. But it should be done at the factory!

:grin:
Mike

#39 contedracula

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Posted 15 September 2012 - 10:41 AM

@Ed
I got it! ;-)

You have a PM

Thanks
Gianluca

#40 Sarkikos

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Posted 15 September 2012 - 12:52 PM

Yep, that's the ticket! :ubetcha:

#41 APM M.Ludes

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Posted 16 September 2012 - 08:26 AM

Finaly, my designer got some time to design this project, will be something we starting soon, but delivery in 2013 only

#42 contedracula

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Posted 16 September 2012 - 11:05 AM

Markus,
have you estimated price for this Planets Killer ? :watching:

For the Planetary Observing activity ( not Photos with Camera ) you prefer this one or Intes Micro MakNewton 8/10" with yours and Matthias improvments?


Thanks
Gianluca

#43 APM M.Ludes

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Posted 17 September 2012 - 10:55 AM

Hi Gianluca

first we do design, then we get prices , then we calculate final cost, we will have to pay all tooling for glas and mechanics, so it will be NOT cheap, I may do 4 or 5 pc total for beginning and see how they selling.

the other question I cannot answere till I have them side by side

#44 contedracula

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Posted 23 November 2012 - 10:26 AM

Hello Markus,
News?

Thanks
Gianluca






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