Old 16-04-2017, 08:58 AM
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Balance of newtonians

My camera causes balance issues when the eq mount is in certain positions with a newtonian telescope (i.e. Hanging to the left). Is there a solution to this?
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Old 16-04-2017, 09:17 AM
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Camelopardalis (Dunk)
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Stick something to the other side, roughly the same weight, as a counterbalance.
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Old 16-04-2017, 09:25 AM
markas (Mark)
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Set up the system with the OTA facing to the SCP, and the RA counterweight bar pointing directly down.

Looking from directly in front on the mount, a line from the centre of the OTA camera port to the centre of gravity of the camera/focuser unit needs to be exactly parallel with the RA counterweight bar - ie the RA axis.

This gives lateral symmetry about the DE axis. If you have the DE axis balanced longitudinally and the RA axis balanced, then the system should be balanced in all positions.

If you want to rotate the camera for framing (or any other reason) you need a lateral counterweight to bring the lateral balance to the centreline of the mount axes.

Hope this helps. With direct drive mounts getting 'perfect' balance in all positions is critical; with standard mounts it is less so.

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Old 16-04-2017, 09:54 AM
glend (Glen)
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Many mounts actually track better out of balance, as it can be used to keep gear systems meshed. Even in belt drive systems, if the ring and worm gear are still used a bit of unbalance can keep lash down.
On my 10" imaging newt i don't worry too much about the camera and filter wheel and coma corrector hanging off the focuser, i just balance the tube on DEC to be slightly rear heavy ( which works best on my mount), and east heavy ( which is focuser side anyway) on RA but not much. This seems to work in my situation. On my Mak-newt i have tube rotated in its rings to put the camera as near to the top as i can without blocking the guide scope. Its always best to stay under the rated imaging capacity of your mount, where weight and its placement is less an issue.
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Old 16-04-2017, 01:31 PM
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Agreed, it is better to have slightly more weight toward the gears a whisker out, than the other way where it wont hold tracking.
I found this out when using my G11 some time ago, but that is only my humble opinion

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Old 16-04-2017, 07:29 PM
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Thanks for the great replies. I will definitely try tout the focuser parallel with the counter weights. I have an eq5pro which I think has a max Weight between 9-10kg. My scope+guide scope is 7kg and my camera is ~800g. This is a little to heavy I think,especially since the mount came with two 5kg counterweights.
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Old 18-04-2017, 08:10 AM
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sil (Steve)
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Dont ever expect good performance when close to the weight limit of a mount, 50% of the stated limit is about where you should be. You'll be forever having tracking issues and straining the mount. I always got best performance with setting the scope up with all the gear (making sure cables are not free to dangle/tangle which slightly chanegs weight balance. Manuaaly slew to the position I want to image and balance it there as perfect as possible. THEN do my star alignment etc. by the time the mount is up and tracking my target its rock steady in that position. Being close enough is just not good enough.
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Old 19-04-2017, 08:51 PM
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NorthernLight (Max)

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I used to have the same problem on my Newton with my DSLR incl. a battery grip and a Powermate inbetween the camera and the focuser.
I solved it by turning the telescope tube around so that the camera is pointing down. Moving the camera and associated bits down and close to the mount improved everything balance related dramatically. I go 12.5min exposures with subarcsecond guiding and round stars without hearing the mount working. Hope this helps.
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Old 19-04-2017, 10:32 PM
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Northern Light, I really appreciate this response. I think this will work wonders.
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