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Counter ballance questions


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what is considered best product i see a few when searched for, i like the look of the Astro Engineering 3D system but cant find a review on it. (not too badly priced either) the meade obviously works well but quite pricey.

i thought you guys would know better than me guessing?

i'm all ears and open to suggestion. ohh nearly forgot to mention this is for the lx200 12".

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I never found a 3D counterweight system necessary on the 12" lx200.

The tube can be balanced in Dec by using suitable weights ( + velcro wrist weights -Tesco) on a bar.

Balancing in RA by adding the same to the fork arm(s)

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see i knew you guys were holding back. thanks.

another question if i may-

the scope in normal use has quite a weight to the front of the tube, by the time i put the electric focus and say the 12m TV EP on it i'm about level but if i add the losmandy with the etx guide i tend to be back heavy, at present this scope is not mounted and all i am doing is working what is required to make it work correctly when on the pier in the observatory it will be wedged.

i'm concerned i may damage the RA and DEC motors adn need to make sure i get my head round how to distribute the weight around the scope to stop this happening.

Barkis thankyou for the link to the review.

Merlin66, if you could explain a little further how i work out what weight is required for the fork arms i would appreciate it as this is a big block for me that you can probably make easy.? i hope.

Thanks for looking in on this.

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Getting the balance right is ultra-critical for autoguiding. It isn't really about giving the motors an easier life, though it will do that. When you get the scope on a wedge the balance requirements will be quite different from the alt-az confiuration.

Olly

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When the fork is mounted on the wedge and you have all the gear attached.....

Set the scope on the meridian pointing South with the tube horizontal.....Lock the RA axis.

by attaching weights on the tube (as necessary - along a bar?) get the tube to balance, with the Dec unclutched.

Now lock the Dec and unlock the RA axis. hold and rotate the fork to see which way is out of balance. I assume you'll need to add some weight to the East fork....

Here I wrap a velcro weight around the bottom of the East fork arm...adding weight until the fork is in balance when pointed East through the meridian to the West.

That's about it....it should certainly get you well enough balanced so the motors work OK and guiding is possible....I used PHD with my Lx200 - no issues.

HTH

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Thanks Merelin66, you can let go of my hand now...

makes it so much more simple when you talk to someone thats been there and done it before.. you dont fancy setting my Pier for me do you??

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Something you may want to consider here is what type of dew shield/dew prevention you will use. You will still need one even if you are in an observatory and with the 3d balance arrangement you are thinking about it will be very tricky to wrap one of the pvc-type ones around the tube and keep it there, because the bracket holding the balance lies very close to the end of the tube. Unless you cut out a piece to allow for this it will be unsteady. Same goes for the camping mat style of dew shield, although if you screw up when cutting it you’ve only lost a few quid as opposed to the ridiculous price they charge for the pvc rubbish. Wrapping a dew prevention strap around the outside of the shield will help keep it in place but it is not ideal. If you are building a dome you must leave plenty of room above the telescope to allow for slewing with dew shield in place.

If you are nose heavy it might be worthwhile to replace the Meade finder with a 66mm, or larger, refractor instead. This can then be added to with a one or two inch diagonal and eyepieces of different weights to suit your set-up. You will have to buy bigger rings of course but it may be worth thinking about. One great benefit of this is that you get to see how objects appear in two very different scopes and there are some objects which do look better when viewed through a small refractor instead of a large SCT.

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Thanks for the input Cleetus Van Damme.

I have been collecting equipment over the past few months in the hope of having most of what i wanted by the time the Obsy was complete, it would seem the kit is here but the Obsy wont be for some time. no free weekends to dig the damn hole.

I'm now sporting a very nice condition 12"lx200, a wedge that requires some work to get it back in tip top condition, a nice Dewbuster with 4 auto / 6 Aux ports that should be good for the ETX 90 that will sit on it, i got a losmandy system on ebay at fair money the other week, i have a home made dew band around the front end of the SCT and a small Dew Strap for the front of the EXT, i have just repaired a Meade illuminated Ep and i have my hands on a dew shield that will have to do the job until i have some more spare cash for a solid shield, by the time the ETX is mounted with the guide cam i'm sure this lot will be back heavy.

I will have to take my chances with cutting the shield (no real problem) i ordered the weight system, but shall most likely add the Velcro weight to the forks as required.

i have see peoples systems mounted with 2 cameras and wanted to know if one was the guide while the other was shooting? or if it might be that they were taking black and white along side colour shots at the same time? i like to look through an EP but i also want to image, i need a neat and tidy way of doing this without removing to much equipment every time...suggestions welcomed?

anyhow i feel i am running before i have walked, my wants far exceed my ability at present, what i need to do is get it mounted and forget the tech and get on with the viewing for the time being... i have a list of things i want to see before i look at my list of what i want to achieve with all this gear.. i do enjoy learning and reading though so throw it out there and i will try to take in any info or suggestions before i get to far in to all this.

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