Guide scope fitted - how to balance?

[Omaroo]

OK - I've fitted the 80mm f/11 refractor as a guide scope, and have the ToUcam fitted to the end.

Given the weight (not huge, but still noticeable) how should I go about balancing the whole unit? I guess that it has to be done from underneath - and it should balance along the Dec axis as best it can with the clutch disengaged. Can I ask how do most people do this?

[h0ughy]

go to the bintel web site and look up weight balance system for 12" SCT


Bintel 2D Counterweight System (12" SCT)
$129.00

[Omaroo]

OK - let me re-phrase. How do I go about determining the weight distribution, and just how much weight is required?

The reason I ask is that in polar mode, the scope chages its balance characteristics as it spins on both axes. If it's balanced with the fork stright up and the Dec at around 15 degrees, it sits there with both locks off no problems and seems balanced as I nudge it in either direction without crashing either way. As soon as I spin the fork on the RA axis it's OK until it gets to about 45 degrees - after which you can hear the motors change pitch and whine.

My question is, I guess, can they be balanced in all planes and all possible attitudes?

PS h0ughy - I hope you've still got that wedge.....

[Merlin66]

I used a couple of standard aluminium channel 12 x 25 cut to length .. about 500mm and drilled and tapped various 6mm holes along the length. The counterweights are 60mm diameter x 20mm thick disks again drilled and tapped 6mm They weigh about 500gms each x 4 They can be stacked and located to give dec balance.
For balance in RA I find the drive arm is always heavier than the other so I drilled and tapped a 6mm hole in the west ( non drive) arm and use the same weights to provide balance. I used a similar channel to mount the guide scope ( 90ETX)
Works well for me.

[Omaroo]

Yep - There are 2 x 750gm weights tucked into the left arm's old battery compartment. It seems to balance out the Dec motor/worm drive that is mounted in the right arm OK. Even then, as it spins on RA in polar mode you can hear the motor pitch change, so I've still got work to do before I go ruining a Dec drive. :doh:

[jase]

There are plent of resources available to help you achieve optimal balance:

http://www.mapug-astronomy.net/AstroDesigns/MAPUG/Balancing_Loading.htm#anchor-top

Check this out.:thumbsup:

[h0ughy]

wedge is yours, you have seen what I have done to the 12";) the weight set also helps in this regard look up information on the MAPUG web page

[h0ughy]

LOl as I was typing Jase answered my MAPUG addition.

[Omaroo]

What have you done to your 12"?

[h0ughy]

http://www.iceinspace.com.au/forum/showthread.php?t=14044
:P :D :scared: :whistle: