Wednesday, May 19, 2010

The Meade LXD-55 RA Motor Goes Nuts: The Problem and the Fix

The Meade LXD-55 mount

As you noticed, April 2010 marked the first time in months since deep sky astrophotos appeared in the monthly gallery. Why? My Meade LXD-55 mount went nuts.

Four years ago, I bought a Meade LXD-55 mount/Orion ED80 combo on Ebay for about $500. How did I get it so cheap? The seller's friend did what was described as a "hyper tune" on the mount in an effort to improve performance. The result: the go-to got screwed up and no longer worked. However, the tracking motors worked perfectly, which was all I wanted in a mount at the time. In the intervening years, the LXD-55 has served as my trusty photographic platform for all the deep sky shots you see on this website. Then came November.

Without any warning, the right ascension (RA) motor, which compensates for the Earth's rotation during photography, started going nuts. The only speed the motor would move was on max (3 degrees a second) when I tried to move it with the controller pad. Even worse, the RA drive moved in a fast, jerky manner that made any photography impossible.

I seriously thought my mount might be toast.

Taking the mount inside, I began to wonder what could possibly be going wrong. My first thought was a stuck/bad button. Supporting this theory, my garage door opener never works as well in the cold as it does in the warm. My hope was that the controller was simply having a hard time getting used to the cold November nights. So the mount stayed inside a few nights to warm up before I took it back outside to try again.

The same thing happened. The problem was more serious.

Doing some research, I came across, and exhausted many options including: bad power sources, bad connections, and wiring problems. Nothing I did along these lines helped. That left me with the last option out there: computer issues.

At first, this didn't seem to make any sense as the computer had never been right in the first place. The mount with the messed up computer had worked perfectly fine for me for about four years so why would it go crazy now? It just didn't seem to make any sense. Despite that, I decided to go ahead and try a computer reset through the hand controller. This was the second to last option before pulling out the motors and risking screwing them up even more.

So I did the reset.

After the reset was done, a message came scrolling across the controller that the reset was finished and that the mount needed to be turned off. I did as instructed. Now I wondered if the mount was even going to work at all. Turing the mount on, the controller came to life, a good sign. Now for the real test: using the RA motor. I got the mount ready to go and nothing weird happened, so far so good. Finally, I selected a slew speed of a degree a second and hit the button to move the mount.

Success! It worked.

Now feeling that the problem was fixed, I set the mount to tracking speed and hit the button again. The result: the barely audible sound of the tracking motors operating returned. The mount was finally cured of the gremlins that had plagued it for months. It was time for deep sky astrophotography again!

Hopefully, this story of my Meade LXD-55 will find its way to someone experiencing a similar problem. A quick reset can do a lot without a costly trip back to Meade for factory service. In fact, I don't even know if Meade will service the LXD-55 now that it has been replaced by the LXD-75. Disclaimer: I am not an expert at fixing computerized mounts, I'm just a guy who likes to do astrophotography who had a mount go nuts. If you have a different kind of mount, it is important to do research based on your own equipment before trying anything drastic. However, for fellow LXD-55 users, this tale will hopefully come in handy.

Up next:
The Olympus Stylus 550WP review is almost done and should be up in a few days.



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