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Russian Maks

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#26 maroubra_boy

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Posted 18 April 2021 - 07:24 AM

I built a removable insulating cover for my MK-66. That way I can cool it down faster without the cover and put it on just before observing.

 

However, I still have the feeling that I have some turbulence left in most cases  scratchhead2.gif . When I manage to properly cool it, it performs very well smile.gif .

 

CS, Sebastian 

Sebastian,

 

The whole purpose of insulating an OTA is to NOT let it cool, or rather to slow the rate of cooling.  Insulation by definition cannot cannot accelerate or assist cooling, only slow it down.

 

Think about what is happening with a bare OTA - the tube cools down much faster than the primary mirror and baffle tube, so a heat differential is created between the cool tube and the warm internal components, and so a heat plume is generated inside the OTA as the heat is transferred through the air inside the OTA.  Now if the OTA is insulated, the tube will not cool faster than the primary mirror and baffle tube so a heat differential is not created and hence there will be no heat plume generated.

 

The entire purpose of this is not to prevent the cooling of the OTA, just to slow it right down.  You can still wait for the OTA to cool, but depending on the size and type of scope you have, your location and the starting temp of the OTA this can take anywhere between one to four hours.  But by insulating the OTA, there is no waiting cool down period so you can rip the maximum magnification that seeing conditions will allow from the very start.

 

The trick with insulating the OTA is not to make the wrap too light or thin as this will not provide the necessary insulation properties required.  Better to have thicker/more effective insulation as this improves the slowing of the cool-down rate.  But this also does not mean that the insulation that is required needs to be an expensive material.  I've made a stupendously effective wrap out of a re-purposed yoga mat that I rescued from the tip! smile.gif  The best part of this mod as an ATM project is for you to explore the materials you readily have at hand, and the upshot of this could be that you spend either nothing or very little on the wrap, or a nominal amount to buy new materials.

 

PLEASE NOTE that this insulating trick/mod is ONLY for closed tube OTA's such as SCT's and Maks, not for open tube OTA's.  Refractors could benefit as well, but not by the same margin because their internal components are totally different.

 

Alex.


Edited by maroubra_boy, 18 April 2021 - 07:27 AM.

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#27 SebastianTS

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Posted 18 April 2021 - 07:36 AM

Alex,

 

thank you very much for your explanation. I in deed misunderstood this principle. But now as you explained it, it makes perfect sense smile.gif. I used quite inexpensive foil made of polystyrene. Next time I will not remove it but maybe fix it even tighter.

 

CS, Sebastian


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#28 maroubra_boy

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Posted 18 April 2021 - 07:38 AM

My own lot of Russian-made glass, a Santel MK91 - a 9" f/13.5 Mak that uses Intes Deluxe optics.  Blooming screamer of a scope.

 

Below are pics of it in the timber case I made for it, and with the Coreflute insulating wrap I also made for it.  The wire that is seen on the outside of the OTA is to power the small fan in the dewshield section of the wrap that is used to keep the corrector dry from dew.  It's just a small 40mm 12V fan that uses bugger all power and is so effective, and not a joule of heat used to deep the optics dry.

 

Alex.

Attached Thumbnails

  • Santel Mak case (9).JPG
  • Santel Mak case (12).JPG
  • 9in Santel Maksutov.jpg

Edited by maroubra_boy, 18 April 2021 - 07:45 AM.

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#29 maroubra_boy

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Posted 18 April 2021 - 07:42 AM

Alex,

 

thank you very much for your explanation. I in deed misunderstood this principle. But now as you explained it, it makes perfect sense smile.gif. I used quite inexpensive foil made of polystyrene. Next time I will not remove it but maybe fix it even tighter.

 

CS, Sebastian

If you have a sufficient amount of that polystyrene foil, you won't go wrong by doubling up on it over the first one you made.  This will greatly improve the insulating properties of this light material.

 

Alex.


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#30 blackhaz

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Posted 18 April 2021 - 07:52 AM

My review of 10" Aries f/15 MCT if anyone is interested:

http://trafyx.com/bao/ariesmk10.html

 

At the bottom of the article there are links to images simulating how Jupiter appeared in the eyepiece in different seeing conditions. Sorry for the encoding glitches, it was 10 years ago, something was lost somewhere...

 

Max


Edited by blackhaz, 18 April 2021 - 07:53 AM.

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#31 luxo II

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Posted 18 April 2021 - 08:12 AM

@Max, great to see another rare big one in use, interesting re the reducers as I'm looking for one.

 

Sebastian,

 

If the insulation is doing its job the internal plume will be reduced or eliminated completely by the time you're set up, so there is no real need to cool the scope. Reducing the rate of heat loss also means the corrector will take longer to dew over - quite possibly remaining dew-free for as long as you want to observe.

 

I know many cover the backend, but I'm fairly sure it doesn't hurt to leave the back of the mak uncovered. Heat will be lost that way and the primary will cool, which doesn't matter provided you have something to prevent dew forming on the corrector. My 10" has  quartz mirrors with a very open backend, which I've tried enclosed vs open and so far I can't tell if there's any visible effect, either way, though the scope has seen little use for the past 6 months as the weather here has been truly abysmal.

 

I've also tried both a dewcap (without and with a fan) and a heater strap around the OTA behind the corrector. Using the heater strap did keep the dew off, but caused internal turbulence affecting the resolution at high power, as one would expect, even at a low setting of 4W. At 12W the turbulence inside was so bad that magnifications above 120X were pointless.  OTOH using a fan in the dewcap worked as expected with no issue, and considering the trivial amount of power required, this is clearly preferable to a heater strap.


Edited by luxo II, 18 April 2021 - 08:33 AM.

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#32 vahe

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Posted 18 April 2021 - 08:38 AM

Initially I tried Reflectix wrap for my 8" Mak, it did help but it still allowed internal currents to develop, then a fellow CN member suggested a different insulation wrap, this material is called Prodex, it looks like Reflectix but has a thicker core and much higher R value, as you can see in the attached picture I wrapped the Mak tightly with this material and used Velcro straps to hold them in place, the back is left open.

.

This past Mars season I used the insulated Mak at very high powers, over 300x, and the image remained refractor steady with no trace of tube currents.

.

Vahe

Attached Thumbnails

  • TEC200-13.jpg

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#33 StarAlert

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Posted 18 April 2021 - 08:56 AM

Initially I tried Reflectix wrap for my 8" Mak, it did help but it still allowed internal currents to develop, then a fellow CN member suggested a different insulation wrap, this material is called Prodex, it looks like Reflectix but has a thicker core and much higher R value, as you can see in the attached picture I wrapped the Mak tightly with this material and used Velcro straps to hold them in place, the back is left open.

.

This past Mars season I used the insulated Mak at very high powers, over 300x, and the image remained refractor steady with no trace of tube currents.

.

Vahe

I doubt it's much higher...

 

https://neo.ne.gov/i...ss exaggeration.


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#34 vahe

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Posted 18 April 2021 - 10:17 AM

I doubt it's much higher...

 

https://neo.ne.gov/i...ss exaggeration.

Regarding insulation in general, I am an architect and in my line of work I have to deal with variety of insulation types, what we architects use for buildings are not suitable for wrapping telescope tubes. When it comes to buildings, in our line of work, Reflectix, Prodex or any one of these thin flexible insulation materials are not taken seriously and are never used.

.
Now, coming to insulation wraps for telescopes, the only way to evaluate these wrap around materials is to try them and see how they perform, never mind the over exaggerated claims by their manufacturers.
In my case I tried Reflectix first and Prodex later and concluded that between the two Prodex did a better job of insulating the Mak.

.

Vahe


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#35 maroubra_boy

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Posted 18 April 2021 - 05:54 PM

Initially I tried Reflectix wrap for my 8" Mak, it did help but it still allowed internal currents to develop...

 

Vahe

As I mentioned earlier, there is a balance to be struck with the material you are using to make your wrap with and it having enough insulating qualities for YOUR scope.  Reflectix is often used as one material.  What is often not done is investigate if one layer is enough or if more is required.  Too many of us resort to just one layer of any given material.  No harm what so ever in beefing up the wrapping.  Use your imagination.

 

There is no right or wrong here material wise.  Only experimenting with different materials will provide the best individual results for different scopes and different conditions.  If you have access to a whole roll of Reflectix, then double up on the layers, or more.  If you have a foam rubber yoga mat use that.  It may cost you nothing, or it may cost you a small amount.  Insulation does not need to be expensive here.  I bought a sheet of white Coreflute to make my wraps.

 

Maks are very often criticised for taking a long time to cool.  Well now there are two options:

1,  Wait for the scope to cool

2,  Slow the rate of cooling by insulating the OTA and forget needing to wait on a cooling period.  Extending the wrap to have it form a dewshield will also extend the dew-free period for the corrector or even help keep it totally dry all night (scope and conditions dependent) and will help keep the scope dry from dew that would otherwise form on the OTA, and help prevent that water from finding its way into the OTA via seams & joints, around the corrector and screw holes.

 

Alex.



#36 vahe

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Posted 18 April 2021 - 06:29 PM

 If you have a foam rubber yoga mat use that.  

 

Yes, I totally forgot to mention that, I have two rolls of 5mm thick yoga matts in dark gray color and also two rolls of something called camping pads in 1/2" thickness in blue color, both are foam rubber flexible materials suitable for insulating Maks.

Since my initial experiment with Prodex did the trick I did not bother using these mats, but since I have them I will probably use them one day.

.

Vahe


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#37 dweller25

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Posted 19 April 2021 - 02:09 AM

I found two layers of reflectix was needed for best results with my Intes 715


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#38 bierbelly

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Posted 19 April 2021 - 07:54 PM

Going back around 2005 I owned a IM M603 plus at the same time a Skywatcher 120ED, the views on planetary were nit and tuck but if we had a night of good seeing the mac would spank the 120ED as far as observing at higher powers but one you got to lunar the 120ED was left in the dust. The 120ED had a wider FOV but that was it, color correction was very good on that scope but the M603 had none, I really should have had my head examined why I sold the 603 but the next scope was a C9.25 in which back then I had a bad case of aperture fever. MY older brother owns three Intes scopes a MK67 and IM M703 and M500, he has hinted that he might sell me his MK67, I now own an Orion late sample 150 mac which is not bad at all but those Intes scopes were always a tad better in the optics, some of the China made scope are decent but overall smoothness and optical quality still goes to those Russian mad mac's.


I had an MK67. Great scope except the limited focus distance. I spent more time figuring out what extender I needed for what EP than I did observing.

#39 Jaimo!

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Posted 19 April 2021 - 08:48 PM

Gentlemen, there is another on going thread discussing insulation.  Let's please stay on topic.



#40 bortle2

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Posted 19 April 2021 - 09:56 PM

Interestingly, Intes-Micro Alter M606 (152mm f/6 astrograph) is currently being sold at teleskop-express.de as new. FWIW (from the linked page):

 

 

This telescopes are no longer serial products, they are made only on customers special wish and order and requirements, so they are fully custommade telescopes now.



#41 luxo II

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Posted 20 April 2021 - 02:04 AM

TS have had that listed for at least a year; it will be hard to sell - see https://www.cloudyni...strograph-r1472

This is an example of Intes half-witted execution - good glass in a terrible OTA. I can see why in the end APM decided to buy the glass only and build maks in Germany.

Edited by luxo II, 20 April 2021 - 02:12 AM.


#42 photoracer18

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Posted 20 April 2021 - 03:14 PM

In the case of Intes/Intes Micro, scopes disappeared because Putin ordered all their commercial production to cease.

 

He redirected their production to satisfy military & scientific demand.frown.gif

Same for LOMO also.



#43 sonny486

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Posted 26 April 2021 - 10:03 AM

I have three Intes Micro scopes:  MN86 - MN66 and an ITE MN76 Carbon Fiber.

 

They are really great scopes, the only issue I have is the very shallow backfocus.  I cannot add a filter Wheel to my cameras due to the very shallow backfocus.  I can do OSC with a filter at the end of the 2" adapter, however I can't even fit a filter slider on the most shallowest cameras I have.

 

The MN86 is big and heavy, the MN66 I use for visual use (Planets) and usually get wonderful views with it.

 

I also have two 190MN by SkyWatcher and Orion.  I am converting the Orion into a Carbon Fiber scope.  

 

The 190MN has been my goto scope for many occasions, so I want to make it lighter.

 

 

 

-Sonny


Edited by sonny486, 26 April 2021 - 10:06 AM.


#44 Paul Hyndman

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Posted 26 April 2021 - 10:51 AM

I had an MN86 and suffered the same issue. It's been years since, but here are some notes from optical coupling methods I used to deal with the limited back focus:

 

You may benefit from an optical coupling system. Visually optimized scopes can present a special challenge for imagers, as the focal plane is often formed so close to the tube that cameras or CCDs cannot be accomodated. This can be partially resolved with the use of a relay lens or Barlow to "pull" the image from the OTA, though creating a larger image scale and increased EFR in the process.

 

Denkmeier Optical has a low-amplification 2" Optical Coupling System that, while primarily intended to complement their binoviewer line, may provide relief for "back-focus challenged" scopes as well. Below are a few test shots to illustrate its capabilities. The A/B images themselves were taken within moments of each other, but only rough processing was done, so variations of image quality do exist.   

 

These shots are from a Canon D60 digital SLR and 203mm f/5.9 Mak-Newt using a Denkmeier OCS or TeleVue 2x Powermate (for the reference images). Focus was shifted outwards out from a -12mm (inside) position to a +25mm (available).The images were equally resized (about 20% of the originals) but not cropped, and illustrate the low amplification of the Denkmeier OCS (about 1.25x with the center spacer removed). The larger images were via the Powermate and the smaller from the OCS. With its low amplification factor and preservation of a faster focal ratio, the OCS fills a much needed niche.

Attached Thumbnails

  • Lunar.jpg
  • Orion.jpg
  • Sun.jpg

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#45 sonny486

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Posted 26 April 2021 - 01:47 PM

Thanks!  Will look into the optical coupling system.  I do have a TeleVue 2x powermate that I used for visual only, it never occurred to me to try it with the camera.

 

F6 would go to F12, but that might be fine for planets and bright objects.

 

 

 

 

I had an MN86 and suffered the same issue. It's been years since, but here are some notes from optical coupling methods I used to deal with the limited back focus:

 

You may benefit from an optical coupling system. Visually optimized scopes can present a special challenge for imagers, as the focal plane is often formed so close to the tube that cameras or CCDs cannot be accomodated. This can be partially resolved with the use of a relay lens or Barlow to "pull" the image from the OTA, though creating a larger image scale and increased EFR in the process.

 

Denkmeier Optical has a low-amplification 2" Optical Coupling System that, while primarily intended to complement their binoviewer line, may provide relief for "back-focus challenged" scopes as well. Below are a few test shots to illustrate its capabilities. The A/B images themselves were taken within moments of each other, but only rough processing was done, so variations of image quality do exist.   

 

These shots are from a Canon D60 digital SLR and 203mm f/5.9 Mak-Newt using a Denkmeier OCS or TeleVue 2x Powermate (for the reference images). Focus was shifted outwards out from a -12mm (inside) position to a +25mm (available).The images were equally resized (about 20% of the originals) but not cropped, and illustrate the low amplification of the Denkmeier OCS (about 1.25x with the center spacer removed). The larger images were via the Powermate and the smaller from the OCS. With its low amplification factor and preservation of a faster focal ratio, the OCS fills a much needed niche.



#46 luxo II

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Posted 26 April 2021 - 02:13 PM

For planets you need a focal ratio approximately 5 x the pixel spacing in microns; for the ASI533 that means f/18..f/20.

Edited by luxo II, 26 April 2021 - 02:14 PM.


#47 titanio

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Posted 02 May 2021 - 10:17 AM

Hi,

 

Russian Maksutov? Yes I like them, I had three of them, Intes micro MN78 standard versiĆ³n, M815  deluxe and MN86 deluxe Quartz mirrors by Matthias With, I used them only with super monocentrics eyepieces in mono version, and the NN78 was the best of them for me. 

Now I have the Maksutovs zen 240 f12.5 and SW180 f15, also very nice  Maksutovs which  I use  with binoviewer. Zen has something special, very good contrast and dark background. SW  maksutov is very light and easy to use in AZ iOptron pro  mount.

So far I do not miss my former Russian Maksutov. 

 

Cheers


Edited by titanio, 02 May 2021 - 10:19 AM.


#48 photoracer18

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Posted 03 May 2021 - 04:49 PM

I have one Intes Micro, the MN56, one Intes, the MK67, and one LOMO, the Astelle 95. I don't play favorites. I have previously owned the Mk65, MK66 and the LOMO Astele 133.5.



#49 Borodog

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Posted 03 May 2021 - 05:56 PM

I built a removable insulating cover for my MK-66. That way I can cool it down faster without the cover and put it on just before observing.

 

sml_gallery_348218_16428_8033330.jpg

 

However, I still have the feeling that I have some turbulence left in most cases  scratchhead2.gif . When I manage to properly cool it, it performs very well smile.gif .

 

CS, Sebastian 

Put the insulation on before you take it outside, or don't put it on at all. You either have to get the whole thing cool, or keep the whole thing warm. What you are actually doing is *maximizing* the thermal gradient in the scope before putting the insulation on by partially cooling it prior to insulating it. The internal thermal gradient is what drives internal convection. A uniformly cold scope doesn't convect. A uniformly warm scope doesn't convect. A scope full of warm air and a cold OTA will convect, regardless of whether you then insulate the already cold OTA or not.


Edited by Borodog, 03 May 2021 - 05:57 PM.

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#50 StarAlert

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Posted 03 May 2021 - 05:58 PM

I just placed a want ad for an Intes M715. I need something to pair with a Tak DZ/DL for ISS lunar transits. It will go on an iOptron AZMP. I plan to use the Tak for full disc images and the Mak for higher-resolution images. With a 2x barlow, I think it will work well the ASI174MM. I'll keep my fingers crossed. I got lucky with the MK91. Maybe someone nearby has the M715. 




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