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Balance function


cfm2004

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Two days ago I discovered that the version 5116 also has the "Balance" feature.

Since I have never used this feature and I have not found mention in the manual, what is the best way to use it?

 

Best regards,

Cristina

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Hi Cristina,

 

I tried to find the description in the old autoslew manuals but did not find them.

So here's how I use the balance feature:

 

I start with putting the telescope horizontal as well as the counterweight shaft horizontal. Then I start the balance feature for the dec-axis. The dec-axis swings back and forth (about 15 degrees if I remember correctly) and the two bar-graphs indicate the amount of current required to swing the axis. One graph indicates the forward motion, the other one the backward motion. While the axis swings, I try to remember the maximum position of both graphs. The idea is that once both graphs show the same maxima, balance is perfect as it takes the same current to swing the axis in both directions.

If the maximums are not identical, move the telescope forward or back until the graphs are symmetrical. With a heavy scope, you will see quite a difference if you move the scope by few millimeters.

For an optimum balance, it's important that the scope is in the configuration that you intend to use (including CCD and filterwheel, dew cap, dew heater) and that the focuser is in the focus position.

Once the telescope is balanced in the dec-axis, you do the same thing with the RA-axis. This usually is easier as you can easily move one of the counterwheights until you achieve optimum balance.

If you want, you can check the balance in other positions as well. It might be difficult to achieve optimum balance in all positions if you e.g. have a heavy finder scope off-axis or if your filterwheel is asymetrical ...

 

Hope this helps,

 

Robert

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  • 3 weeks later...

I have just download the DDM85 product manual, but I found no reference to the function balance. I remember seeing something about it in an old manual, you happen to have one available? You can send it to me in private?

 

Best regards,

Cristina

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  • 2 weeks later...

Note that the instructions say 'move the counterweights along the counterweight shaft back and forth until both the top and bottom red bars are perpendicular to each other'.

 

Perhaps, 'in line with each other' or 'level with each other' would be better.

 

(Sorry, being pedantic, I know). :)

Edited by GeorgeCarey
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Thank you very much for the manual!

I had already solved a couple of days ago. I got there through the logic of looking at the two bars.

 

Yes George, I agree with you. The word "perpendicular" is not very explanatory.

 

I saved the manual... you never know...

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No prob ;)

There is more about balance in P.Kellers post here:

 

http://forum.astrosysteme.com/index.php?/topic/96-cant-move-more-than-a-few-degs-in-dec-position-error-clear-servoerror/&do=findComment&comment=388

 

You can easily have balance in one position but have problems in another position, especially with heavy CCD or filterwheel you need to add a counterweight opposite to the CCD on the tube.

 http://www.astrooptik.com/asa/Balance.pdf

This is something new that is not mentioned in the manual.

 

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