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CEM60EC Vs Avalon Fast Reverse (SynScan)

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#1 RolkaLT

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Posted 21 March 2019 - 11:00 AM

Hi all,

 

Not been here for a while.

 

started with NEQ6 two years ago and want to upgrade to a bit better mount.

 

Not sure if it is worth at all.

 

At the moment I have 130PDS + ASi1600mm and a piggybacked Samyang 135mm + Canon, all on NEQ6 and guiding is not very reliable... sometimes 0.6" Total RMS sometimes 1.2...

Simply...

I cannot leave it for whole night unsupervised...

Without Piggyback toys, guiding was always around 0.7, was good enough, but the lack of clear skies push me towards the dual rig and NEQ6 does not shine bright in this field... at least in my hands...

 

Thinking to step up to a bit more expensive mount.

 

At the moment I have 2 on the list:

1) New CEM60EC + Tri-Pier tripod.

2) Used Avalon Fast Reverse (SynScan) with Avalon tripod.

 

Price will be almost the same...

 

I am on the fence, with both legs towards CEM6EC, because:

1) New;

2) Encoder in RA, (but not sure how much guiding benefits from it...);

3) Built-in or customised cable management system;

4) Not essential, but nice bonuses, like GPS and Polar Alignment Routine without visible Polaris (which I do not see in my back-garden).

 

But I afraid to jump... I need a push maybe...

Not sure if any of these mounts will perform better than NEQ6 with piggybacked Newtonian which was quite a challenge to balance.

 

Make a sale please! smile.gif I must be ready for the next AP season and have some sleep during clear nights smile.gif


Edited by RolkaLT, 21 March 2019 - 11:00 AM.


#2 gotak

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Posted 21 March 2019 - 11:29 AM

I just ordered a cem60ec. That's my bet.

Avalon is nice but no used one I can find locally.
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#3 DuncanM

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Posted 21 March 2019 - 11:43 AM

There are things you can do to beef up your existing mount:

 

stiffen the tripod with a centre tray or leg braces

 

use higher quality alt-az adjuster bolts

 

Heavier CW shaft

 

that should allow it to better handle the extra weight.

 

Use an OAG.

 

A CEM60 will guide better but wind will still be an issue. My CEM60 (non EC) has excellent tracking whilst carrying a 10in SCT but it struggles in windy conditions. 



#4 RolkaLT

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Posted 21 March 2019 - 12:09 PM

There are things you can do to beef up your existing mount:

 

stiffen the tripod with a centre tray or leg braces

 

use higher quality alt-az adjuster bolts

 

Heavier CW shaft

 

that should allow it to better handle the extra weight.

 

Use an OAG.

 

A CEM60 will guide better but wind will still be an issue. My CEM60 (non EC) has excellent tracking whilst carrying a 10in SCT but it struggles in windy conditions. 

I am with OAG already... I was made to go OAG way not because of the guiding issues, but it was quite difficult to get a proper balance with a piggyback camera and a separate guiding scope, plus autofocuser on Newtonian...

 

As per advises: 

I use 2x5kg CW pushed quite close to the mount.

My PA error is quite good, PHD2 Assistant shows lower than 1" during 600sec and I do not do longer than 600sec exposures. 

My set up is stationary in the garden. I do not think leg braces will help a lot as sometimes guiding is very good.

 

Simply not sure why...

Sometimes screen is fully red from PHD2 corrections and without any particular reason. And it now happens around 50/50 of the time mount used...

Seeing of-course changes, but not to the level to make such a big impact I think...

Thats why I think of Encoders... They probably will smooth things a bit or maybe drastically...

 

 



#5 bobzeq25

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Posted 21 March 2019 - 12:16 PM

I have a CEM60 (non-EC), like it.

 

I decided a single encoder with no sophisticated sky modeling backing it up, was not worth the money.  Especially if you guide.  I think it's mostly a way some people can go unguided, with a dash of advertising.

 

Mounts with really effective precision encoders have 2, and sophisticated sky modeling.  Like a $10,000 10Micron.  Completely different deal.  With the CEM60EC all you're correcting for is PE, which ain't everything.

 

I _love_ the internal cabling.  Once I figured things out, things run fine on USB2, for DSO work, with my equipment.

 

I have an observatory, no wind.  Guiding still depends _a lot_ on seeing.  On steady nights (for me, chronically bad seeing), I get 0.6.  On average nights 0.8.  It can go over 1.0, then FWHMs are silly, and it's not really worth imaging.

 

Your site _will_ vary.  <smile>

 

If you get one.  Read the manual carefully.  Do not confuse the adjustment screws for clutches, the simply set the range over which the worm can float, under magnetic control.  _Never_ tighten them, although you need to find the limits by lightly bottoming.  Operated properly, I think they're robust.


Edited by bobzeq25, 21 March 2019 - 12:21 PM.

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#6 DuncanM

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Posted 21 March 2019 - 12:23 PM

Stiffening the tripod is the no.1 thing you can do to strengthen it to resist flexure, as the stock spreader it too close to the tripod head.

 

Here's how I modded mine:

 

http://www.sfu.ca/~dmunro/tripod.JPG

 

However, it sounds like something else is going on if your guiding is suddenly erratic. Is there a correlation between the guide problems and wind? 2ndly, over time, the worm/worm gear mesh will need adjusting and there are youtube guides on how to do that.

 

I also have a CEM60 non-EC mount and it is somewhat superior to an EQ-6 but it still struggles in wind.


Edited by DuncanM, 21 March 2019 - 12:26 PM.


#7 petert913

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Posted 21 March 2019 - 12:35 PM

Definitely get the tri-pier mount.  My iOptron tripod (for my iEQ45 pro) is not rigid.  


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#8 RolkaLT

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Posted 21 March 2019 - 02:34 PM

Stiffening the tripod is the no.1 thing you can do to strengthen it to resist flexure, as the stock spreader it too close to the tripod head.

 

Here's how I modded mine:

 

http://www.sfu.ca/~dmunro/tripod.JPG

 

However, it sounds like something else is going on if your guiding is suddenly erratic. Is there a correlation between the guide problems and wind? 2ndly, over time, the worm/worm gear mesh will need adjusting and there are youtube guides on how to do that.

 

I also have a CEM60 non-EC mount and it is somewhat superior to an EQ-6 but it still struggles in wind.

nice :)

In fact I do have 1 meter long threaded rod, I do not remember the diameter, but quite close, maybe would fit..
but I do not believe it is the solution as mount guides or not and my garden is quite "enclosed" and wind usually is not an issue.

 

I suspect it is related to balance, but if something is off, it will be just a very tiny bit and NEQ6, in fact, likes that tiny bit, - usually.

So I am really puzzled. 

And as I haven't got a lots of clear nights here in London to experiment/"dance around" the mount all the time, - decided to throw some money at it.

I almost sure, Mesu200 would sort this headache, but "this stone" is a bit too heavy for my wallet ;)



#9 schmeah

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Posted 22 March 2019 - 05:23 AM

Which Avalon (Linear I presume, but I believe the earliest M Unos came with Syn Scan also)? I like to buy new, and most are very happy with their CEM60s. But the consistent performance and reliability of the Avalon’s is what justifies the price.

 

Derek 


Edited by schmeah, 22 March 2019 - 05:26 AM.

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#10 gotak

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Posted 22 March 2019 - 06:24 AM

nice :)
In fact I do have 1 meter long threaded rod, I do not remember the diameter, but quite close, maybe would fit..
but I do not believe it is the solution as mount guides or not and my garden is quite "enclosed" and wind usually is not an issue.

I suspect it is related to balance, but if something is off, it will be just a very tiny bit and NEQ6, in fact, likes that tiny bit, - usually.
So I am really puzzled.
And as I haven't got a lots of clear nights here in London to experiment/"dance around" the mount all the time, - decided to throw some money at it.
I almost sure, Mesu200 would sort this headache, but "this stone" is a bit too heavy for my wallet ;)


Would it make more sense to do an upgrade under a cost limit and use the difference to build a observatory instead? Just having the walls make a huge difference in what constitutes wind or no wind. And if you automate it then you can even catch the partly clear nights even if rain is forecast for later or the clear bits starts later st night.

I think just adding more mount is not always the best solution.

#11 gotak

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Posted 22 March 2019 - 07:21 AM

Which Avalon (Linear I presume, but I believe the earliest M Unos came with Syn Scan also)? I like to buy new, and most are very happy with their CEM60s. But the consistent performance and reliability of the Avalon’s is what justifies the price.

 

Derek 

My iOptron ieq45 pro is utterly consistent and reliable after the initial get to know each other phase. And I expect my cem60ec when it arrives to continue that trend.

 

As such I tend to think the more expensive mounts justify their price by their price. Just like my wife's hand bags :).


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#12 schmeah

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Posted 22 March 2019 - 09:56 AM

My iOptron ieq45 pro is utterly consistent and reliable after the initial get to know each other phase. And I expect my cem60ec when it arrives to continue that trend.

 

As such I tend to think the more expensive mounts justify their price by their price. Just like my wife's hand bags smile.gif.

I was referring more to consistency from mount to mount, not  night to night performance of an individual proven mount. The general perception is that less expensive mounts are less expensive because the quality control is not the same, therefore even though most mounts can perform exceptionally well, there will be a larger proportion of lemons out there compared to more expensive mounts. 



#13 RolkaLT

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Posted 22 March 2019 - 10:11 AM

I was referring more to consistency from mount to mount, not  night to night performance of an individual proven mount. The general perception is that less expensive mounts are less expensive because the quality control is not the same, therefore even though most mounts can perform exceptionally well, there will be a larger proportion of lemons out there compared to more expensive mounts. 

And that's why new,  with warranty,  attracts my attention... +RA with EC....

 

Used one, even if it's Avalon, = the black cat in the black bag anyway...



#14 gotak

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Posted 22 March 2019 - 10:28 AM

I was referring more to consistency from mount to mount, not  night to night performance of an individual proven mount. The general perception is that less expensive mounts are less expensive because the quality control is not the same, therefore even though most mounts can perform exceptionally well, there will be a larger proportion of lemons out there compared to more expensive mounts. 

I don't really know if there are that many lemons out there. There are a lot more of the less expensive mounts out and about so even if the given bad percentage is the same it would seem more just from the additional number of posts. And you will see a lot fewer issue post here for a lot of expensive mounts due to many of them having their own dedicated forums.

 

I find that general perception is worth not that much. The further up I have gotten in my career the more I see that humans are a very peculiar and irrational species. And it is almost always the case no two person has the same perception of the same topic or issue.

 

Back to the topic at hand. I prefer to spend less, work on minor issues and get similar performance. For me I enjoy the effort and it's a hobby (aka a "pass" time) I am not making money from this so there's not a lot to justify spending more to save a few hours of enjoyable work with my fingers in the grease.



#15 RolkaLT

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Posted 22 March 2019 - 11:50 AM

And thats why I have 130PDS, 

Cheap, but quite nice quality, and I mod a hell out of it without any frustration. 

 

My autofocuser is DIY wit temp compensation and etc and etc. Bluetooth connectivity project next.

 

The only thing I do not want to play around, -  is the MOUNT smile.gif as I do not feel confident to play with gears, worms and etc... It simply needs to do it's job

as I am always happy to put my fingers into optics, electronics or software which is placed on it... 


Edited by RolkaLT, 22 March 2019 - 01:04 PM.


#16 gotak

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Posted 22 March 2019 - 12:40 PM

The mount mechanically is no more complex than anything else we use mechanically.

In the case of most people it's a simple worm and wheel.

At first I felt pretty apprehensive about adjusting my mount but after a while I realized that in general it didn't seemed to be that sensitive to adjustments. As long as everything went back in a way that wasn't binding or lose it worked more or less the same.

It also explain why the ioptron instructions were so general. At first I kept thinking they need to tell you more precisely how it should be adjusted but it turns out finger feel works more than well enough.


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