Richardo, the tube is solid skywatcher varient and weighs a ton.! If there is flexure in that set up ill be a monkeys uncle. I have gone already to great lengths to make sure it isn't a issue, and as such i have already machined a losmandy D saddle style head replacemnt, the dovetail for the actual newt is 25mm thick and the rings are steel
. The guide rings are ADM and are bolted to the scope rings, and i would assume with only a DSI 2 hanging off the mount it should be fine as the DSLR hangs off it and keeps perfect focus (i also lock focus once i have it and refocus during the evening). Presently that racks in at 25kgs with everything as is :S. I even went as far as to change the Primary mirror cell to a Orion Optics 9 point floating mirror support and I machined a new secondary mirror arrangement from billet aluminium and stainless steel I know that thing doesn't move
.
Im pretty sure that my issues are mount related as im still tuning it after pulling the mount to bits for a service.
I also machine up for people those adaptors for the finder guiders and alot of other things too
I do have one but find that unless my polar alignment is right on the money (those blasted trees) then the finder guider doesn't work too well.
Oh and yes
i do like the look of it all in white and the "metallic" blue feet
Quote:
Originally Posted by richardo
Hi Brenden,
all happening and good when things come together with home contrived gear!
Your set up looks pretty darn sexy all in white..
I would next be looking for flexure... oh yes, the fun of it all!
If your auto guiding is under .5 error then this be the next place to check..
What is your tube made from... rolled steel or aluminium?? How thick??
Substantial do you think??
Is there flex/ sagging or slight movement in the tube where the focuser is attached? Things to check for this is orientation of imaging train in correlation to image orientation and star elongation.
How about the focuser on the ED80... the stock focusers are crap...if there's any slight movement here, mucho problemos!
The scope rings where your ED is attached could be another weak spot.
I've had far better success with a faster guide scope than using the ED.
Most of the time with longer focal length guiders, it will chase poor to average seeing.
You could always try what many are using these days... 9x50 finder. Seems to work well for many folk. Plus would cut down an immense amount of weight on your mount!
Maybe there is some slippage with your clutch system due to pushing your mounts capacity.....
Flexure is truly a bain of us newtonian users. To track down any slight movement anywhere can be a whole new can of worms, and the cause of hair loss, greying and frequent emotional outbursts    :rolleyes : 
Look forward to your further advancements.
Rich |
Quote:
Originally Posted by troypiggo
Good stuff. When I can get out, I'll be testing out my 10" for this sort of stuff, and some Ha to boot. Will definitely be using your stuff as a benchmark, coz it all looks good! |
Im no where near benchmark yet troy! though thankyou for the compliment
Quote:
Originally Posted by DavidU
Nice stuff Brendan. Looks like you need a chain saw.  |
Quote:
Originally Posted by danielsun
Images are coming along nicely though you might want to get a chain saw onto them trees. 
Cheers Daniel. |
Dan and David.... i keep threatening to sabotage the trees... problem is there is a dirty great big German Shepard in that yard and he doesn't like anybody
Quote:
Originally Posted by Moon
Brendan
I agree with Rich. Because the elongation looks worse in the 15min subs compared to the 10 mins subs I would be looking for flexure.
Why don't you try putting a dovetail plate on the top of the scope and then you can add one more tube ring to the guide scope - but this time really close to (or around) the guide camera. I did this and it made a 1000% improvement.
As a test, next time when you have PHD running, try pushing the guide camera with your finger a bit and see how much movement there is.
James
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I utilize maximdl as PHD i find is very sub standard, when i push the scope with my finger theres plently of movement as you might expect for a overloaded mount
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Maxim has a great feature that you input your guide and imaging scope, and it will tell you in arc seconds how big the guiding errors are, when i was taking my Prawn shot, i was actively tuning the mount but i learnt that i can tell what the seeing is like though the guide movements. and as such i was sitting at about .5 - .8 seconds of arc adjustments but it started going furry again after about 20 minutes and i had touched nothing, on inspection of the sky there was a lot of sinterlation.
I think before i can start evaluating if my equipment has flexure and give it a quantitive figure my mount has to be running dead smooth. other wise your chasing a horse that never going to come home. and you will get grey hair real quick.
one thing at a time.
I think just in terms of clarity the 10" has come a very long way, as i am achieving a FWHM of 3 where i used to get 5-7. I can attribute this to increased accuracy of the Cats eye collimation equipment+New secondary setup+stable primary cell.
Thank you all though for your comments it makes me want to go out and hit it again to try and squeeze every last bit of lemon juice out of the lemon
..that sky looks pretty sexy 
