dynamic balance for CPC800

[zakkhogan]

Hi all, need some advice on achiving (and understanding) dynamic balancing for my set up please.

 

my imaging set up is a follows:

CPC800 + finder scope

Canon EOS 500D

ZWO 60mm Guide Scope

ASI120mm

Geoptik Counterweight system

 

I can achieve horizontal balance however once i directed the scope over to Bodes, the goto tracking became unreliable. From a quick google dynamic balance is most likely the issue. 

 

What do i need to do to achive this please

 

Thanks

Craig

 

[michael8554]

The Geoptic system won't work for you, you need a 3D system:

http://www.astronomyreviews.com/sct/da3d.htm

This gives balance between the equator and zenith pointing South, and then additional fisherman's lead weights are added to the forks  to balance pointing West and East. 

But it's never perfect. 

Michael 

[zakkhogan]

Thanks for the reply on both Michael.

I will find and upload the phd logs when I get back from work, but is it possible that balance is the cause also. 

 

Re 3D counter weights, I think I'm going to  mod my geopitic system but tapping the weight and inserting threaded bar, do you think that would work ? 

 

Also when I Google I see some have a what look like small side ways looking weight? 

Greatly appreciated.

 

Craig

[michael8554]

Yes adding threaded rod will work. 

I think that bar is for hand-tightening. 

Are you clear on how to use the system for balancing? 

Could  you post an image of how your guidescope is attached to the scope? 

Look up Differential Flexture Guidescopes

Camera pixels are measured in microns, so flex of only a few microns will shift the guiding several pixels. 

Michael 

[zakkhogan]

Hey Michael 

 

Thank you so much for you time,  I modded the geoptik to ad the 3 dimensional aspect and it seems to have achieved equilibrium, i've attached a video below,

i then connected to PHD and managed to use the manual guide function to move the cope in all for directions so hopefully this is the cure. 

My guidescope info

*ZWO 60mm guidescope

*Skywatcher guidescope mount

https://www.harrisontelescopes.co.uk/acatalog/skywatcher-guidescope-mount.html?gclid=Cj0KCQjw6_vzBRCIARIsAOs54z7agRNf0RDjhtfiTmSRRONyYSRtc0Nh4bFFXKcnPjnGS6Dq0r8okMMaAjvJEALw_wcB

*Celestron piggy back mount

-------------

 

The zwo sits in the skywatcher mount, the skywatcher mount attaches to the piggy back mount.

 

The ZWO 60mm guide scope has a focal length of 280mm which i had already input into phd, 

It comes with guide rings attached to a dove tail, The adjustment screws on the rings are nylon and i have fastened up as tight as i can.

And the dove tail sit in the skywatcher mount which is what i use to do my adjustments .

 

Pics and vidoes attached.

Im soo very greatfully for your advice,  Im feel very positive about it all again

 

 

[zakkhogan]

the guider set up

[michael8554]

Great job on the 3D balance !

I had one of those Skywatcher Guidescope stages, but found that the ZWO ASI120MM always found a guidestar, so I never adjusted it.

So I took it off, sold it, and mounted the guidescope directly onto the imaging scope.

Reduces load on the mount and helps balance by putting the guidescope weight closer to the Dec axis.

Let us know how the guiding goes.

Michael

[zakkhogan]

thank you so much for the advice i honestly could have cried,  

[zakkhogan]

Hey Michael, 

 

The count weight system seems to be working great, locating every target accurately while fully loaded. 

 

Guide is better but still not working correctly..  its giving me the following warning

 

'Advisory: Little or no east movement was measured, so guiding will probably be impaired. Check the guide cable and use the Manual Guide tool to confirm basic operation of the mount.'   

 

any idea what this might be

[zakkhogan]

looks like it was a bad lead