Dob Wobble part 2

[mikeyggg]

Hi everyone,Just had my Dob outside with Baader zoom ep attached, and tried to really take the time to get the adjusting tensions etc right by messing with the tighness of the handles.There just didn't seem to be an optimal setting where I could move the scope and have it stay in the position that I'd moved it to. It would always want to move an inch or so downward, so I ended up having to oversompensate with its position and then allow it to fall to where I wanted to view. As you can imagine, this was not ideal.....Still, I managed to see M31 (and saw either M32 or M110 for the first time. Which ever one it was was to the lower right of M31 in the FOV).I then had a look at the moon, which involved putting the scope on a garden chair in order to see over the fence and then holding it in place with one hand while I clicked the zoom lens in and out with the other. Obviously the moon was wobbling quite a bit. (Still looked amazing though especially after I added the neodymium filter).I then thought I'd try my Celestron 10mm elux eyepiece and hey presto!! All balance problems suddenly dissapeared!.So....it looks like my brand new Baader zoom is just to heavy for the mount.A shame, because I could definitely notice a difference in quality between the Baader and the Celestron.On my last postG1ZmOsuggested a large magnet could be added as a counterweight. Has anyone tried this (and where would one purchase said magnet?) or are there any other solutions for the problem?It'd be a shame if I couldn't use the Baader since it really did produce a better image that the Celestron.Anyhow, sorry for the long post. All suggestions appreciated.Mike..

[Astronut]

I use a plastic milk bottle full of sand with 4 magnetic discs glued to the side of the bottle. This gives me a weight of 3 or 4lbs. Different combinations of eyepiece, paracorr and powermate give different weights so I just move the bottle closer or further away from the altitude bearings to compensate.

Magnets are here:

http://www.first4magnets.com/25mm-dia-x-2mm-3m-self-adhesive-magnets-65-c.asp

I covered each magnet with a same size disc of gaffer tape so the magnets wouldn't scratch the tube's paint. I may need to get 4 more magnets so I can attach the bottle to the underside or side of the tube opposite the focuser for better balance as 4 magnets isn't quite strong enough for hanging the bottle on the bottom of the tube.

[John]

The need to add weight to the mirror end of a dobsonian scope is a common issue and many dobs need this when heavier eyepieces are in the focusser. Astronut's solution seems a great way to do it - I'm going to need to do something along these lines myself when my new dob arrives - I've 2 eyepieces that weigh 1.6 and 2 lbs respectively.

Another solution I've seen is to hang a short piece of cloth covered metal chain from the back of the dob, like this:

(click to enlarge)

John

[Doc]

I done this.......

[Astro_Baby]

Not a dob owner but even on an EQ mount the weight differences between EPs can make a difference.

You could always mount some kind of basket at the back end and use some lead shot in pre loaded bags to balance it all up. I was thinking of something along those lines for my scope.