Setting ddm60 Est limit?

[YahooGroup]

This is a transfered topic from the ASA Yahoo Group.

 

 

Posted By: pauloastro69 Fri May 3, 2013 5:36 am

Hello everyone,
I have set in AS the option "how far can you go through the Meridian with your
German Mount?" to '-12' degrees, and the telescope is not hitting the west side
of the pier with the counterweight pointing est and a meridian flip is
happening.

But the problem now is that after the meridian flip and the counterweight
pointing west the mount try's to approach the object from the est side with the
telescope hitting the est side of the pier.

Is it possible to avoid this?
Is there a way to set a limit on the est side too?

best regards,
Paulo Nunes.

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Posted By: jbaj82  Fri May 3, 2013 10:00 am

Why did you fill in a negative number, can't you go through the meridian with
your setup?

What value do you use with "Minimum flip distance for east-side slews"?

Regards,

Jeffrey

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Posted By: pauloastro69 Wed May 8, 2013 2:41 pm

Dear Jeffrey,
Yes, I use a negative value for "how far can you go through the Meridian with
your German Mount?" option, because my newton telescope will strike the pier.

For the "Minimum flip distance for east-side slews" I'm using the same value of
-12 degrees or the same as the "how far can you go through the Meridian (...)"
option.

Best regards,
Paulo.

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Posted By: bernd_eppinger Wed May 8, 2013 10:32 pm

Hi, Paulo,

To be honest, I don't think I understand what you are trying to achieve.

You say you must enter a negative number (-12°) for "How far can you go through the meridian...", because otherwise your telescope hits the pier when the counterweight is on the east side. My conclusion is that your telescope can't reach the meridian when coming from the east side before hitting the pier. However, if your pier (or probably tripod) is symmetric, you have the same problem on the west side, i.e. when approaching from the west side, you can't come closer to the meridian than 12° either.

In this situation, you want to make a meridian flip. But you have no position in the sky which you can reach from both sides of the pier. Moreover, there's a remarkable gap of 24° with celestial positions which you can't reach at all (simplification, not taking into account that in reality the distance to the meridian depends on the altitude, too). Now when your observed object approaches the meridian from east and comes closer than 12°, you can't make the required meridian flip simply because you can't reach this position from any side of the pier.

Assuming I understood your problem correctly, my proposal would be to solve the underlying mechanical problem. For example, if you have a tripod, you can create more room for your telescope by adding a pier extension (which is what I did). I admit that it is difficult to precisely calculate the required length of the pier extension in advance.


Best regards,

Bernd

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Posted By: pauloastro69 Fri May 10, 2013 11:35 am

Hello Bernd,
Thank you for your reply.

">there's a remarkable gap of 24° with celestial positions
which you can't reach at all".

Yes, your explanation of my problem is correct..
My pier, not tripod, is a 30cm square made of concrete, and 50cm height from the
ground.

I was trying to automate my observatory after manually opening the roof but with
my present telescope, the AG14, and my actual pier there is always this 'small'
problem. With my last scope, a C11, the pier configuration was perfect. But now
with the AG14 I really have to make serious mechanical changes in one or both.

I was hopping to delay this problem some more time with a software configuration
change, but as this seems impossible with Autoslew I will have to address this
sooner.

Thanks again, Bernd.
My Best regards,
Paulo.