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Ed Sunder
sage
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Reged: 12/11/07

Loc: Flintstone, GA
LXD75 motor problem new
      #3741502 - 04/12/10 10:03 PM

If the LXD series isn't supposed to be discussed here in this forum let me know...

I've been using my LXD75 mount for about 2 years now and it's been a champ - I've hypertuned it and then re-hypertuned it about 9 months ago and it's been working great. I generally do astrophotography and with the guidescope giving input commands it does a good job. Tonight, I decided to retrain the drives because it's been overcorrecting a bit with the backlash. However, like an idiot, instead of clicking on the train drives, I clicked on LXD55/75 adjust. The instructions on that are the same as on the train drives and so when I clicked okay, it started moving like crazy. I quickly clicked Mode to exit and it stopped. The scope didn't run into anything - it just moved about 90 degrees about as fast as it could. After that, the RA gear only moves in full speed. I can change the speed and the Dec gear changes, but RA is moving at Max, even when I turn on quiet slew. I ran calibrate drives I tried to train (but have you ever tried that when RA is on MAX?!). It can't park the scope - it can't do anything. If I let it run enough, it'll give me a motor fault (though again, I'm not letting it run into anything or put any undue stress on things). Turned it off and on - same problem every time.

I thought maybe the encoder wheel might have a spiderweb or something (we've had cloudy or windy weather for weeks, but of course I used it successfully for hours last night...), but the RA encoder wheel looks clean and straight - everything looks fine.

Will a handset reset fix this? Is there something else I should do? I'm worried and would love some reassurance. I'm probably going to go ahead and do a handset reset to see (and if it works, I'll post back), but I thought I'd ask around and see if anyone else had run into this.

Thanks


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Ed Sunder
sage
*****

Reged: 12/11/07

Loc: Flintstone, GA
Re: LXD75 motor problem new [Re: Ed Sunder]
      #3747708 - 04/15/10 10:10 PM

To start with, I meant Dec when I said RA and vice versa - sometimes the brain swaps things...

Okay, I started with the handbox reset command. The handbox reset and the problem was still there. Next, I hooked up the scope to my laptop and I ran the Autostar Updater software and flashed the handbox entirely - wiping it and replacing it with the latest firmware (43Eg). I replaced everything in that thing. I then booted it up, entered the date and time and it ran a calibrate motors command. The calibration seems to move both motors the normal amount and then it was ready for alignment. I changed the speed and sure enough, the Dec gear still only moves at Max speed while the RA gear works fine. I also got a Motor Fault error after moving the thing past about 150 degrees. Tried a couple reboots - still has a problem. I guess I'm going to have to call Meade on this one - unfortunately it's out of warranty.

Any suggestions?


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Ed Sunder
sage
*****

Reged: 12/11/07

Loc: Flintstone, GA
Re: LXD75 motor problem new [Re: Ed Sunder]
      #3747859 - 04/15/10 11:28 PM

One more thing - does anyone know if the light used by the encoder is visible? I'm going to power up the scope tomorrow with everything plugged in, but the mount on my work bench and the Dec motor opened up so I can see stuff spin - there doesn't appear to be anything blocking the encoder disc and everything appears clean. I'd like to know if I'll be able to see the light if it's working. If so, then if it's not visible, then I'll know the light has burned out.

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Skywatchr
Carpal Tunnel
*****

Reged: 06/03/06

Loc: North-Central Pa.
Re: LXD75 motor problem new [Re: Ed Sunder]
      #3752391 - 04/18/10 02:58 PM

What I have found most often is the handbox cable. Not that it is bad, but has some minor oxidation on the plugs and doesn't always get a clear signal feedback from the encoders. I use Caig Labs DeOxit D5 and it seems to take care of some of those "gremlins" for the cables.
Usually a hard reset will clear any faults. And try clearing out the "stray" bits often leftover from firmware updates. They can confuse the Autostar.


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Ed Sunder
sage
*****

Reged: 12/11/07

Loc: Flintstone, GA
Re: LXD75 motor problem new [Re: Skywatchr]
      #3757840 - 04/20/10 10:44 PM

Hmmm - that definitely worth a try - I'll take a look at the cables and see if cleaning that up might fix the issue. Fortunatly, a new Dec motor is only about $130 if worst comes to worst.

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Ed Sunder
sage
*****

Reged: 12/11/07

Loc: Flintstone, GA
Re: LXD75 motor problem new [Re: Ed Sunder]
      #3759703 - 04/21/10 07:04 PM

Connections were pretty clean, but I cleaned them anyway - still no luck - I took the whole thing apart and everything still looks good, it just only runs at Max. I'm going to go ahead and get a replacement Dec drive and see if that fixes it.

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Ed Sunder
sage
*****

Reged: 12/11/07

Loc: Flintstone, GA
Re: LXD75 motor problem new [Re: Ed Sunder]
      #3774578 - 04/28/10 10:52 PM

No luck with the replacement Dec drive. I'm getting a replacement RA drive (which contains the motor controller etc. now. If that doesn't fix it, it must be the handbox. I'll update here when I find out what's required to fix it.

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George D
Vendor
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Reged: 04/13/10

Loc: So Cal
Re: LXD75 motor problem new [Re: Ed Sunder]
      #3791048 - 05/07/10 01:05 AM

This thread is a week old so you may have solved your problem already.
To answer the "visible light" question; Most encoder assemblies use infrared LED's and are not in the visible light spectrum.

Did you double check the ALT/AZ ratio numbers under "telescope setup"? They should reflect the numbers for your scope. If the ratios are blank for some reason, and you can select your telescope type and reset them, it would be a good place to start.

Another possibility here, is that somehow the encoder signals got shifted or damaged.

I've been told that the LDX-75 motor setup is a good one and I have never seen one or had the opportunity to work on one. I just had an LX-200 motor apart and replaced a motor in it, and I am pretty confident that I could repair your motor for you.

If you want to send it to me in SoCal, I'll take a look at it and attempt to repair it for you, and send it back. I won't charge you anything to do this, just pay for the shipping each way.

As one of my "rules to live by" says;
"There is nothing I can break so bad, that a new one wouldn't fix"...
..
George


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Ed Sunder
sage
*****

Reged: 12/11/07

Loc: Flintstone, GA
Re: LXD75 motor problem new [Re: George D]
      #3796097 - 05/09/10 06:49 PM

Thanks to everyone for their suggestions - I've solved the problem, but I don't know if my advice is going to work for everyone. I suspect that the problem was with the hand controller. Here's why:

I replaced, initially the Dec motor assembly (~$90). This did not solve the problem. I then replaced the RA motor assembly (which contains the connectors for everything) (~$120). When I connected the new RA to the new Dec, attached the Autostar and plugged it in (though I hadn't attached it to the scope yet), the RA gear started running very quickly. However, I could run both motors at lower speeds, but the RA was (when I wasn't pressing a button) running very fast. I went through the setup menu and chose Calibrate Motors. That fixed it.

Sounds good-right? I just had to replace either the RA motor or both RA and Dec (~$210 - compared to $200 for Meade to fix it) right? Um, not so fast. Just for giggles, I hooked up my old motors and the Autostar and plugged it in. It did the same quick runaway RA until I did calibrate motors and then it worked too. Aaaaah! Did I just blow $210? The answer is maybe. I think the hand controller needed to be plugged into another scope to truly reset. I had already flashed the memory of the controller and that hadn't fixed the problem, but once I was able to hook it up to a "different" scope (as far as it was concerned), everything was hunky dory. I had some nice viewing afterward and everything worked perfectly.

So now, I've trained the RA/Dec backlash and tonight, if its not windy, I'll be doing some PE correction. These new motor assemblies are a lot quieter than my old ones and so now i'm using the new ones and have the old ones in storage so if something breaks, I've got spares.

Long story short, if you have this same problem, I'd suggest connecting your hand controller to someone else's (compatible) Meade scope and then back to yours to see if that fixes it.


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dave907
newbie


Reged: 08/10/13

Re: LXD75 motor problem new [Re: Ed Sunder]
      #6023961 - 08/13/13 09:04 PM

I had this same problem today when I was testing out my used LDX75 for the first time. The declination motor moved at full speed no matter what speed the handbox was set on. I plugged in my controller to an old DS-80 telescope and used it, plugged it back in to the LXD75 and still no fix. Then I tried the calibrate motors function with my original handbox on the LXD75 mount and voila, the dec motor slews at the same rate as the RA motor now, all I had to do was calibrate the motors.

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Ed Holland
Carpal Tunnel


Reged: 06/16/10

Loc: San Jose, CA and Oxford, UK
Re: LXD75 motor problem new [Re: dave907]
      #6028418 - 08/16/13 01:41 AM

I read this thread with some glimmer of hope, after my LXD75 started acting strangely tonight. It does not operate in Dec at all, and the RA is behaving strangely. I've cleaned and verified all the connections... tried an alternative handbox, checked power and attempted the calibrate motors function. RA operated, but not Dec.

So, do I go back to Meade (This will be a second repair for motor faults...) or try and find replacement motor(s).

May I ask from where the parts may be purchased, if I decide to take that route?

Thanks in advance,

Ed


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Cliff Hipsher
Pooh-Bah
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Reged: 12/31/08

Loc: North Chesterfield, VA
Re: LXD75 motor problem new [Re: Ed Holland]
      #6028652 - 08/16/13 07:38 AM

I hate to say this, but you are pretty much out of luck. That mount in no longer in production, and parts are going to be difficult to find. At one point Meade sold motor assemblies for around $150.00 each, and just recently I've seen complete mounts on eBay in the $400.00 range. About the only other source for parts may be Telescope Warehouse .

Good Luck!


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Ed Holland
Carpal Tunnel


Reged: 06/16/10

Loc: San Jose, CA and Oxford, UK
Re: LXD75 motor problem new [Re: Cliff Hipsher]
      #6028999 - 08/16/13 11:49 AM

Thanks, I'll make some calls today and post back with progress (or lack of it).

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Ed Holland
Carpal Tunnel


Reged: 06/16/10

Loc: San Jose, CA and Oxford, UK
Re: LXD75 motor problem new [Re: Ed Holland]
      #6029195 - 08/16/13 01:29 PM

Bump

Contrary to expectations, after a 5 minute phone call to Meade I was able to place order for a new set of motors. Nor was there any long wait, or confusing multi level list of options - I got straight through to a real person. Delivery expected in ~2 weeks according to the representative. There was the option for return/repair but that would have taken ~4 weeks and incurred extra shipping charges.

Hopefully I can get this thing pointing at the sky again (under my control)!

Cheers

Ed


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Cliff Hipsher
Pooh-Bah
***

Reged: 12/31/08

Loc: North Chesterfield, VA
Re: LXD75 motor problem new [Re: Ed Holland]
      #6030533 - 08/17/13 09:30 AM

That is great! I've heard several horror stories about motor assemblies being made from "unobtainium"...

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paul
sage
*****

Reged: 04/14/05

Loc: pa
Re: LXD75 motor problem new [Re: Ed Holland]
      #6040829 - 08/22/13 09:34 PM

Quote:

:) Bump

Contrary to expectations, after a 5 minute phone call to Meade I was able to place order for a new set of motors. Nor was there any long wait, or confusing multi level list of options - I got straight through to a real person. Delivery expected in ~2 weeks according to the representative. There was the option for return/repair but that would have taken ~4 weeks and incurred extra shipping charges.

Hopefully I can get this thing pointing at the sky again (under my control)!

Cheers

Ed



Can I ask you how much they charged?
Thank you


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Ed Holland
Carpal Tunnel


Reged: 06/16/10

Loc: San Jose, CA and Oxford, UK
Re: LXD75 motor problem [Re: paul]
      #6050893 - 08/28/13 03:19 PM

Sorry - I had't checked this thread for a few days.

To answer your question: Two motor assemblies, including the shipping charge came to $290.

Of course I went back to the mount the other day, and turned it on to find it working again as far as I could tell.... but spare motors are a good idea. Besides, I've aways thought the RA motor sounded inconsistent whilst tracking, as if the encoders were suffering a stutter.

Cheers

Ed


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