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Quote:Have you checked your collimation or mirror flop?
Quote:Check to see if the dovetail has any slop when putting the 8 inch on. Otherwise weird effect. Do you have another OTA to try and recreate the effect with another scope? That would tell you if it was limited to something with the Meade.
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Quote:All other things being equal, I would have to look to a problem with the scope/dovetail in this case. As suggested, you could have a mirror flop issue or something else related to the mechanics of the Meade scope.
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Quote:Tom-It could be your balance. I know you check that, but the C11 is much heavier so if you are balancing that setup without the MCX, wires,dew shield etc... the weight difference once you start imaging is not that big a deal. Meanwhile if you balance the 8" OTA sans all the equipment attached, once you put everything on the proportional increase in weight is enough to blow your balance.Just my 2cAl
Quote:Two possibilities in my experience:1. Dovetail. Make sure the main screw and safety screw are cranked down good, and that there is no play in the saddle and that the dovetail is not loose/flexing on the scope.2. Balance. Balance is extremely important to good tracking on the CG5, but this seems to be worse than any balance issue I've seen.I would also check to make sure the tripod/GEM head attachment is not loose somewhere, but why this would not show up with the 11 is beyond me, unless the greater weight is helping keep things together.As for the dovetail? Only one screw can be OK--most Celestron dovetails only have one screw up forward, but there are "outriggers" to keep the dovetail stable.
Quote:Tom-When you balance the C11 you are using 2 11 pound counterweights right? When you use the 8" do you keep the same 2 11 pounders and just slide them up the shaft? Try an experiment with just 1 counterweight with the 8" balanced. I know it sounds weird, but i can get better tracking with my C8 on CG5-AGST with just one 11 lb counterweight than with two...Al
Quote:Thinking outside the box here but I have had the wiring of the MCX pull my mount oh so slightly just at a certain angle for the OTA. This would be from the backlash/slop in the mount and my lack of proper wire mounting. It would only happen with my HD8, when I had it, but would not happen with my HD11.Just a thought.. You should see it in the live view though. It might take a few minutes.
Quote:The dovetail looks secure...but...isn't it a little narrow...or is that just my failing eyes?I would also make sure that the camera is secure when it is on the M8. It isn't flexing for some reason, is it? Dave's question about your cables is a good one...I've been bitten by that gremlin more than once...
Quote:Tom,It sounds like perhaps all things aren't equal. I think you have a variety of possibilities to check out here. I agree with Rod that the dovetail looks a bit narrow which could mean a less solid hold than the standard Celestron dovetail on the C11 (if that is what you are using).
Quote:In addition to the actual mounting points of the dovetail flexing ( your image reminded me of what differential flecked looks like), the dovetail may not be snugged up or has a slight tilt. When I mount my OTA the dovetail is horizontal. More than a few times it has not been tight all the way or crooked. I now rotate the tube around the dec axis 180 deg after attaching it to check for this slack. Another scope I use has the Losmandy style dovetail and mounts solidly but is a pain to slide on.
Quote:It looks like you are using the stock CG5 saddle and a Vixen style dovetail..
Quote:I kinda had my cables ran the same way except I tied them off on the OTA handle. Only while pointing in the east and at about 45-75 degrees. I would be dead center then over a period of about 15sec I could watch the mount shift and the picture shift in the live view. If I grabbed the wires and lifted them up to reduce gravities effect, the issue would stop. As soon as I let go, it would start again until the slop was tight again.
Quote:I realize that in any hobby user error accounts for probably 99% of the issues and it would seem logical that my problem is just that. If the 11" scope had the same problem then it would be concrete but it works to the limit of CG5 tracking. And it has worked consistently everytime where the other 2 scopes have consistently NOT worked everytime. Apparently no one else is having this problem and there are who knows how many CG5's out there with every size of scope possible.