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LXD55 in Alt-Az position - how to

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#1 m1618

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Posted 16 October 2013 - 10:39 PM

My next tinkering project...trying to make my old LXD55 to visual only alt az.

I see how it goes to 90 but what do I use to secure that position? Has anyone else done this? I'm pretty sure I've seen it done here before. Also, would I really need the counterweights then? Thanks for any guidance and pics.

#2 Christopher Erickson

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Posted 17 October 2013 - 04:02 AM

First, you might need a patched Autostar firmware to get it into Alt-Az mode.

Second, the mount does not have to be perfectly-level to work in Alt-Az. The Autostar can compensate for tilt in the mount head.

Third, you can use the tripod legs to make the mount a bit more level.

Fourth, the counterweight(s) are still handy to keep the center of gravity over the center of the tripod.

I hope this helps.

#3 MawkHawk

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Posted 17 October 2013 - 06:46 AM

I received the info below from another CNer (sorry, I can't remember who it was) and it works for me. I do point the scope to Polaris to get it aligned to north then level the scope:

"I pointed the RA axis straight up to the zenith. I knew the ETX125 is Alt-Az, so I selected that as the telescope type. I didn't know the gear ratio of the ETX, but I knew it wasn't 144 teeth. So i plugged in the ratio for the LXD55 equatorial (2.53715). Elevation worked properly but azimuth seemed reversed. So I made the ratio -2.5375. Did the alignment as if it were the ETX and... It worked! Hooray! I turned a GEM into an Alt-Az mount.
A polar alignment is not required. To align, you put the scope and mount in what's called the "home" position. pointing north and scope level. It's not critical like a polar alignment for equatorial mode."

I agree with Eric about using the counterweight(s). I still use mine when I do alt/az if only to keep the entire thing from falling over.

Edit: The gentleman who taught me this is "Shadowalker".

One problem to watch out for is that a motor housing can hit the power cable where it connects to the mount. This happens to me.

#4 m1618

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Posted 17 October 2013 - 08:02 AM

Thank you but I forgot to mention that this LXD55 is all manual, no go-to autostar etc.

So if I have it pointing straight up 90deg and the counterweight/ota perpendicular, in a nutshell, it's as if I would need an extra long latitude adjustment bolt to secure that position. Am I missing something simple? How do I keep it from tipping over latitude wise?

#5 MawkHawk

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Posted 17 October 2013 - 06:49 PM

Oh, I see. On mine the latitude bolts are long enough to work. ScopeStuff sells replacement bolts but I don't know if they are longer than the standard bolts.






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