c14 and a EQ6

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Sorry if this is out of order on this forum, but for visual and Planetary webcam work, would the 12 inch be ok on an EQ6? I don't expect it to be rock solid...

[el_draco]

It would probably crush it...;)

[robz]

Tim, in my opinion, after having talked to many who have used the 12 with the EQ6, it will be fine for planetary visual and photography/capture.

Bear in mind that the any extras that are going to be mounted on or hanging off that tube may bring you to thin ice territory.

The mount can handle 20kg(conservatively - and can be tweaked to handle more)............the 12 inch Meade SCT OTA is a tad over 16kg, so you could still use a large eyepeice or compact camera and a Telrad, star diagonal and still be within limits.

[trek1701]

The Duckadang Celestron C14 sitting on an NEQ6Pro





http://www.iceinspace.com.au/forum/showthread.php?t=60499

[robz]

I have been informed by one person here in Perth that the EQ6 when heavily tweaked/worked on has been used successfully in imaging with a payload of 28kg.

This of course is is an exception to the rule, but does indicate that 16-20 kg for non critical work is definately possible with the EQ6.

[macsen2]

.................using a 12 on an EQ6,no problem..for guiding using a gso finder scope[shortened 30mm]with a dsi pro 11[very light system]................................... ..

[pmrid]

The thread title refers to a C14 but the discussion seems to centre more around a 12". The C14 in the Duckadang thread mentioned below is mine and I did indeed mount the C14 on an NEQ6Pro. But only to get it off the ground and to try some preliminary collimation tweaks - not to actually use either visually or for imaging. The weight that had to be carried on the weight bar to balance the bare scope was huge - and balancing really difficult. I would not recommend that course to anyone.
The C14 weighed 25 kgs or so with the rings and Losmandy bar attached and nothing else. If you add a decent eyepiece and diagonal, you can add another 1-2 Kgs to that.
A 12" SCT would be another issue if the weight was significantly below that - and I see from the discussion that there may be a difference of 6 Kgs or more in the bare OTAs. That may bring it within an EQ6's range but it would still be at the top end of that range and therefore not much use for imaging. It would be OK for visual and it would track OK though. You'd have to try to keep the slew rates down to reduce stress and load on the motors and other components but it would be manageable.
Peter

[Paul Haese]

I own a C14 too and I would not recommend putting it on an EQ6. The mount is not built for that sort of stress. If you are going to buy a C14 don't skimp on the mount.

[Merlin66]

I've just weighed my 12" Lx OTA with Losmandy dovetail and ADM minirail guide bar it's 17.2Kg
I was considering taking it off the forks (which weigh 15.7Kg by the way)
and putting it on the NEQ6pro....by the time you add the spectroscope/ cameras etc etc I don't think the NEQ6 is up to the job....the OTA is going back onto the forks.

[icytailmark]

a losmandy g11 should handle a c14.

[renormalised]

Should....they can carry 60lbs (about 27kgs).

[toc]

Yes this little discussion was originally part of a for-sale thread for a Meade 12" ACF scope. I think the moderator made little boo boo when they moved it here. :)

FWIW, Ive bought the 12 inch, so it served its purpose :lol:

[toc]

In another thread, there is a comment about how Meade put a heavy iron counter weight in the back of the 12 inch scope, apparently to balance it on a fork mount. Im probably to much of a wimp to try and remove it though. I have a bad track record of 'improving' stuff ;)

[Merlin66]

yes, but did you also buy a NEQ6 mount??

[Merlin66]

Tim,
could you link to that thread?
I've had the 12" for the past six years and never heard of the "big iron weight" - mind you I've never pulled the OTA apart!

[robz]

Now that's interesting!...............anyone else care to comment?

[toc]

Nope - That is the next task :) Im actually considering a GOTOless G11 as well - not sure I can come up with the 4+ grand for the full GOTO'ed G11. Im only going to be using the 12 inch for Visual for the semi long term, so I can probably get by with an EQ6 I think.

[toc]

This is the link for removing the weight from the 7inch MAK:

http://www.astromart.com/articles/article.asp?article_id=658

Apparently they put them in the 10 and 12 inch SCT's as well, but I havent seen pics of that :)

[toc]

Just further on this: Found a link on the Meade yahoo group that details removing the internal counter weight on the LX200 12 inch:

http://tech.groups.yahoo.com/group/sct-user/files/LX200-OTA-disassembly/

[Merlin66]

Just waiting on membership so I can access the info....

[Merlin66]

Hmmmm
Well, you learn something new each day!
I never knew there was such a lump of metal in the back of my 12" Lx200.......:eyepop:

[Tandum]

WoW it really does look like a 5Kg counter weight. I guess it is ...

[Kal]

How strange - I never knew there was a counterweight in the back of the meade SCT's either. I would have assumed that the mirror plus all accessories would add enough weight in the back. I have a C11 and I know when I balance it I have to put it almost all the way forward on the dovetail.

I assume this counterweight is only in the LX fork mounted systems, or is it in the OTA's that are purchased seperately as well?

[renormalised]

I think we can safely assume that all Meade SCT's have this counterweight.

[Merlin66]

Could certainly answer the question as to why the 12" Lx is sooooo much heavier than the Celestron 11"

[robz]

Hi Andrew.
Could this weight be more beneficial than detrimental?
By that I mean the position of the tube/dovetail and center of gravity?
Would be useful on G.E.M.'s possibly?

[Merlin66]

IMHO no not really - it just adds weight which is unecessary - the OTA as mentioned could be slid along the dovetail to achieve balance without this extra weight.
It just puts an extra load onto the mount....Hmmm

[toc]

Im no expert, but I dont see how. Surely most of the weight is going to be in the mirror anyway :shrug:

[Kal]

I'd imagine a big counterweight in the back to be a big heat soak that will only lengthen any cool time of the mirror :shrug:

[Kal]

As I mentioned, I have a C11 (which doesn't have a counterweight as far as I know) and I already have to position the scope all the way forward on my GEM because there is so much weight at the back of the scope. If anything I'd need a counterweight at the very light front end of the scope. I'd imagine for a fork mounted sytem where you want the pivot point to be close to the back of the tube the counterweight could be of an advantage, which is why I queried whether this counterweight is only in the fork mounted LX OTA's or if it is in all Meade 12"/14" OTA's?

[robz]

O.k, so what's the verdict then fellows?.
In the Meade 7 inch Mak article below, the writer states that some OTA's were made WITHOUT counterweights so we are left in the dark here a bit.

I am waiting on a 12 inch LX200 ACF OTA which is only a week or two away.
This will be one of the most recent batches to come out of the factory, so when I get it I'll know soon enough if the weight is in there.

Either way, the removal is way too risky and voids warranty. The process is madness unless you have an older tube model that cost a lot less than new:rolleyes:.

Andrew, it would make sense that your C11's weight is all in the back. The main mirror, holder and focussing mechanism etc. would weigh a lot more than a thin corrector plate and secondary mirror up at the front?

[Merlin66]

I think it's pretty definate that the 12" ( and probably the 10") do have the large cast iron interior counterweight. It makes some sense and a method of getting the OTA close to balance at the Dec axis.

[GrampianStars]

Ahh! NO !
The 12" LX200 GPS doesn't. in fact is rather nose heavy.
I had to add a Peterson on axis rear cell counterweight from :- http://www.petersonengineering.com/sky/balance.htm
and even then the 2D ballance weights are at the extreme rear on the rail for correct ballance.
:question: Shifting the OTA atachment.......... and lighten the scope....... :thumbsup:

[Merlin66]

Rob,
Do you have a bare weight for the 12" GPS OTA??
How does that compare with the 17.2Kg of the 12" Lx Classic????

[toc]

Well the one linked to in this thread does, so I guess its a question of which ones do, and which ones do not. I certainly wont be taking mine apart (when it arrives in a few weeks time) anytime soon :lol:

[renormalised]

It mustn't have been very well balanced to begin with....maybe they just didn't add one to your scope when they were making it. Or if that's the general condition of that size and make of Meade.

[GrampianStars]

Aprox. 16.3Kg when last off the forks. Didn't see a weight in there, will do rebuild and add active cooling in a few months so will double check.
the link provided is a great reference for the LX-200 Classic
http://tech.groups.yahoo.com/group/sct-user/files/LX200-OTA-disassembly/

[robz]

Merlin, 16.4kg for the 12 inch LX200 ACF.
35 lbs from Meade Q&A on the intranet.

[Merlin66]

Hmmm
Only a 0.8Kg difference...doesn't sound like the weight of that lump of iron...more like the weight of my ADM guide bar...

[robz]

Copy that Merlin...............somethin' don't add up here does it?

You would think that a 12 inch SCT ''OTA only'' being marketed by a large well known company has already taken in to account that the OTA is in most cases than not, likely headed for a good quality G.E.M. and not a fork mount.........surely :question:.

[toc]

Time to open her up Robz...:D

[robz]

ummmmmmmmmmmmmmmmmmmmmmm........... ..don't think so:D