Last updated: 31 May 2006

LXD55 8sc logo

This page is for user comments and information of a general nature or items applicable to all LXD55 and LXD75 models. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me and I'll post them. Please use an appropriate Subject Line on your message. Thanks.

Subject:	LXD55 SN10
Sent:	Tuesday, May 30, 2006 18:11:12
From:	Ed Williams (hotstrings1@knology.net)
I am still enjoying your site. I have an ext125 but today bought a used
LXD55 10" Meade and I noticed the manual shows 1 weight but mine has 3
weights on it. I read that you must have it balanced so as not to strain
the motor. So my question is how do I know how much weight to put on?  I
will tell you though that I did what the manual said to balance and was
using the 3 weights which were on it.

I am hoping that it will be great for deep sky what are your thoughts on
this scope?

Thanks in advance,
Mike here: The 10"SN can be a great DSO telescope, especially when used with dark skies. As to weight, just balance it so that the telescope stays put with the axis locks unlocked with whatever weight (eyepiece, camera) you add and whatever number of counterweights are required. If one doesn't work no matter where you place it on the rod (that is, the telescope tube still moves downward with the weight attached), then add another weight. Eventually you should find a position and the right number of weights so that the rod stays horizontal when you let go.
Subject:	LXD55 Mount / Adjusting worm gears
Sent:	Sunday, May 28, 2006 13:32:27
From:	neelsb@yebo.co.za
I just fixed a slipping RA drive according to the advice on your webpage
without a problem. While fixing the slipping RA drive I also noticed a
lot of play on the "silver" gear. I tried adjusting the 3 screws under
the gear housing and this seemed to solve the problem. The gears are now
much tighter.

The questions is  What is the correct way to adjust these screws (I
noticed some references that there are actually 5 screws to be adjusted
and not only the 3 I mentioned). How much should you tighten the screws?
Too much tightening seems to put strain on the motor drives (drives
sound like they are working much harder  afraid that the motors may burn
out). Too little tightening and you end up with loose gears again.

I couldn't find any clear instructions on how exactly to make these
adjustments and any advice would be appreciated.

I have been using your website for the last few years and always found
answers to my questions  except for now on a topic that does not seem to
be covered on the internet.
Mike here: I have never needed to tighten any other gear screws but you should never overtighten them. If you are concerned about them working loose you can try using some sort of "lock tight" material on them. Personally, I avoid that stuff.
Subject:	LXD 75 drive gear setscrew size.
Sent:	Saturday, May 27, 2006 15:39:11
From:	lorrie_s (lorrie_s@sbcglobal.net)
One of my lxd 75 drive gear setscrews is loose.  I do not have an allen
wrench small enough to fit.  I was wondering if you or one of your
readers could help me with the size wrench I need?  If I cannot find the
right size, I was thinking of taking the assembly to a jeweler, unless
someone can come up with another suggestion. ...Thanks, Dennis

Subject:	LXD55
Sent:	Sunday, May 21, 2006 20:00:43
From:	Benjamin Lilly (benny638@yahoo.com)
My name is Benjamin lilly and I came across your site and I am in the
market for a set of LXD55 motors and was wondering if you had any for
sale or knew of someone who is will to part with some. Any help would be
appricated. Thanks

Benjamin G. Lilly
Mike here: Try Telescope Warehouse (link on the Astronomy Links page on my ETX Site).
Subject:	re: LXD 55 Mount Tracking Problem
Sent:	Sunday, May 21, 2006 18:53:08
From:	richard seymour (rseymour@wolfenet.com)
You wrote:
> Scope goes on mount.
> Power up mount.
> Run through setup.
> Manually point towards the biggest nearest star in the sky.

..and that it wouldn't track.

Could you please -fully- describe "run through setup" ???
Click-by-click would be best (so we can see what's being done,
and interpolate what's being missed)

If it's not working, we need to know what you -really- did,
not make assumptions that you got some parts right, and
some parts wrong.

Mike's suggestions ("fake a two star align") is a good one,
and may get you past the hurdle.

have fun

Subject:	LXD 55 Mount Tracking Problem
Sent:	Saturday, May 20, 2006 19:30:39
From:	BRUCE NOVICH (ceteck@optonline.net)
I have an LXD 55 Mount I purchased specifically to point my Coronado
Solar Max 40.   I plan on doing some solar photography and time-lapse

The problem I am having is tracking, specifically RA.    DEC tracking is

To set the mount up I do the following:
Level Tripod
Point North ( since this is a daytime observation I use a compass and
adjust for local magnetic deviation).
Set Local DEC with Welders Level Angle ( 41*).

At this point I am dead on.

Scope goes on mount.
Power up mount.
Run through setup.
Manually point towards the biggest nearest star in the sky.

At this point using the #5 slew setting I am prodding the RA every 30
sec to remain dead on.  If I wait for a minute or two target drifts out
of field.

So what am I doing wrong?

Mike here: Do you have an Autostar or are you just using the EC handcontroller?


Its an Autostar 497, that's what came with the mount.
Mike here: There are two models of the LXD75 mount, the EC model and the AT model. The EC model comes with the EC handcontroller and the AT model comes with the Autostar. Since you have the Autostar, lets try an experiment. Set up in the GEM home position as you did before. But then do an Easy Two Star alignment. Enter the current local time when prompted. When the Autostar prompts you to center the alignment stars just assume they are centered and press ENTER. Then slew over to the Sun. How is the tracking? The better the HOME position the more precise the alignment star centering will be and since you faked the alignment, the better the tracking will be. So try for as accurate a HOME position as you can. Keep in mind that there can be magnetic interference to the compass near the mount (or from other sources).


Mike this is a LXD55 mount
Mike here: Same thing applies. Another possibility is that the telescope optical axis is not parallel to the mount Right Ascension axis.
Subject:	ETX90 OTA on LXD75 mount
Sent:	Saturday, May 20, 2006 17:39:13
From:	mmschementi@optonline.net (mmschementi@optonline.net)
I hope this is in the format that you asked for in your email etiquette.
Also, thanks for such a great site.

OK, after finally making my decision between the LXD75 and CG-5, I have
another question.  I'm buying the LXD75 by itself so I can choose which
OTA to get (probobly a Meade LX200R 8 inch OTA).  But I have to save my
money after buying the mount.  In the meantime,  I'm hoping I can put my
ETX90 on the mount, so I don't have to wait a million years! (SOOO 
EXPENSIVE!!!).  If you have any suggestions on how to proceed, please
tell me.

Just another question- how is the LXD75 mount you just got?  Do you
think a 20lb. Meade OTA (It's a Ritchey Chretien!) and an 80mm apo will
be OK on the mount for imaging, or should I get the 13lb Carbon Fiber
Celestron C8, plus apo?
Mike here: Certainly the LXD75 mount is more stable with heavier loads than the LXD55 mount BUT it is still not designed for super heavy OTAs. I suspect that the refractor models are about as heavy as you could go (I haven't done the math on their weights but that should be a simple exercise for you from their shipping weights). As to mounting an ETX-90 OTA, you would need to get 3.5" mounting rings and an adapter for the LXD head. Losmandy and Scopestuff are good places to start your search. But it won't be cheap if you decide to go this route.


Thank you for the quick reply!  I looked on Scopestuff and I have to say
it is not as expensive as I thought it would be.  I looked at 3.5 inch
rings and the dovetail plate for the LXD75.  It doesn't say anything but
I guess they fit with each other- I hope.  But all of this is just being
prepared.  I still have to buy the mount.  (I already have Autostar so
that saves me money! Sweet deal!)

Subject:	LXD55 SN8 piggyback mount
Sent:	Thursday, May 18, 2006 08:48:13
From:	Dan Piquette (dpiquette@precisionlithograining.com)
I was looking for the screw and thread size for the 2 threaded holes on
the OTA bracket on my SN8.  Would you happen to know this?
Dan Piquette
Mike here: No, I don't.
Subject:	LXD 75 Mount
Sent:	Sunday, May 14, 2006 11:42:16
From:	Greg Kaiser (kizrus@phreego.com)
I am thinking of upgrading my settup from a CGI mount with motors to a
LXD 75 with Goto. I do allot of CCD imaging now with DSIc  and want the
added advantage of the Illuminated polar scope and GOTO with the 497
Plus the autostar suite interface.

Is this a good choice and can I autoguide the LXD75?

Best Regards

Greg Gilbert AZ
Mike here: I just upgraded from a LXD55 to a LXD75 myself but haven't had a chance yet to work with it. But from all reports, the LXD75 is a fine choice. And yes, the DSI can autoguide with an Autostar #497.
Subject:	Autostar off 90 Degrees???
Sent:	Sunday, May 14, 2006 13:11:23
From:	K_Downing (k_downing@comcast.net)
I just started using my LXD75 mount and am having problems with the
Autustar alignment procedure.  (I have had no problems for years with my
ETX-90EC by the way) Every star it chooses is about 90 degrees off to
the east!  I am pretty sure I have the correct location entered and am
using the correct time zone w/daylight savings selected.  Another
oddity...when I choose a one star alignment, the mount moves to Polaris
first and then after ENTER it will proceed to the 90 degree off mark for
the alignment star.  I am stumped and hope it is something easy (and
stupidly missed by me).  I just updated the Autostar to 42Ed for what
it's worth.  Hope you can help.  Thanks in advance anyway and keep up
the terrific job you do on this the ETX site.
Best regards and clear skies!
Kevin Downing
Everett, WA.
Mike here: Have you done a CALIBRATE MOTOR and TRAIN DRIVES since doing the update? If not, do that.


Yes, I calibrated and trained the drives. It tracked just fine on
Jupiter for 2-3 hours last night with minor adjustments.  BTW, when the
drive aligns on Polaris, it moves 90 degrees in RA to the west side of
the mount. I double checked to make sure the mount was in polar home
position (it was). Also, when I had it hooked up inside for testing
w/Autostar Suite, it did the same thing-off about 90 degrees to the
west. What am I doing wrong?

Thanks for the super-fast reply.

Best regards,

Mike here: Oh wait a minute. Since Polaris moves around the Celestial North Pole it CAN be 90 degrees to the side. When you do a One Star Alignment, which lets you align the polar axis, it is normal for the telescope to be off to one side.


OK, I  figured that the Polaris move was normal, because the pattern and
location of Polaris through the finder scope looked an awful lot like
the Starry Night positions for comparison.  However, why are the
alignment stars 90 degrees away from where Autostar expects them to be? 
For instance, last night about 11:15 PM PDT, Autostar expected Vega to
be about 20 degrees west of the zenith.  Actually, it was way off to the
east and so low I couldn't even see it behind my house yet.  It was
almost 2:00 AM before I could see Vega from where the telescope was set
up.  Thus, I figure it is off by about 90 degrees...darned frustrating I
might say.

Anyway, I'll let you chew on that for awhile.  Thanks again for your
rapid feedback and have a nice evening.

Mike here: If you don't align Polaris accurately, you can get a lot of pointing error since the lines of Right Ascension converge at the pole and therefore they get very close together. A small pointing error will have a HUGH Right Ascension error. Could this be the reason the pointing is so far off?


I don't think so.  The view through the finder was very close to the
offset for Polaris from true north.  Besides, it was off 90 degrees with
a three star alignment (inside of the house so it was approximate) the
other night (without the mount first going to Polaris) while testing
Autostar Suite. The goto to Jupiter was off the same 90 degrees or so
last night.  It acts like it is in a different time zone or something...

Just a minute for me to brag a little...last night was first light for
my LXD75 AR6!  (Picture attached) I actually watched the shadow of Io
move across the face of Jupiter, even though seeing was not the best.  I
was jazzed to say the least because my ETX90 would never show that much
detail before, even thought it is a great scope in its own rights.


Well, I'm stumped for now.  I will triple check the location settings in
the Autustar just to be really sure, although I think I am capable of
entering my zip code without too much trouble...haha.

Best regards again,

Mike here: Yep, watching Jovian satellite shadow transits is a real kick! One other thought: try reversing the DEC motor to the west side of the mount and see if the problem repeats.


OK, I'll try that too, although it is set up the way the mount >< are
oriented.  I just hope I don't drop the ota (heavy lil' bugger...) as I
am mounting it 'backwards' for a righty.

I'll let ya know. Thanks alot.

Mike here: As I've noted on my recent LXD75 comments page and on the current LXD Feedback page, there is some controversy regarding placement of the DEC motor housing. I've used mine on the West side on my LXD55 for several years without problems. Others have theirs on the East side, again without problems.

And an update:

I think I might have found the problem.  Even though I had the proper
long-lat entered in the Autostar, the time zone had been entered as +8
(WRONG!!!) versus -8 for my Pacific Time Zone.  I guess the long-lat
settings do not automatically identify the proper time zone.  I sure
hope this is the problem.  What a dummy I am.  Oh well, live and learn. 
If this is not the problem, I am almost too embarrassed to inquire with
you again, but necessity will probably prevail.  So, if this doesn't fix
the error, then I apologize in advance for the forthcoming
correspondence.  ;-)

Have a great day and thank you again for your precious time and help. 
It is greatly appreciated.  BTW, I would like to donate $25.00 to your
website-how do I do this?  I would like to just charge my Debit Card or
maybe through PayPal?  Let me know.

Clear Skies!!!

Mike here: Time is not adjusted from the longitude. See the "Supporting the Mighty ETX Site: Making a Contribution" page on the ETX Site.  Thanks!
Subject:	LXD75-SC/8: East Meets West
Sent:	Monday, May 8, 2006 10:50:13
From:	Dave Wallace (d_wallace@ecrm.com)
Mike said: "Here you can see a close up of the two GEM heads. The LXD75
head has slightly larger axis lock handles than the LXD55. It has arrows
machined onto the mount to indicate the HOME position whereas the LXD55
had arrows pasted on. I was surprised to see the DEC axis arrows would
place the DEC motor housing on the East side of the mount. There has
always been some controversy regarding whether the DEC housing should be
on the West or East side. With my LXD55 I had always placed it on the
West side. The LXD75 manual has photos that show it on either side. I
will checkout the LXD75 with it on the East side."

You definitely *do* want the DEC drive on the *east* side of the mount,
Mike.  The photos are wrong -- go by the arrows.

Another tip:  I found it more convenient and more reliable to put a
velcro strip on the base of the mount, horizontally, between each leg
and the mating strip just behind the display of the Autostar, since the
round legs of the tripod don't afford as much gripping surface as the
flat legs of the 55 did.  I also think that the battery pack is probably
safer left on the ground rather than hanging from the center support.

Altogether, though, it's a fine scope and I'm sure you will enjoy it as
much as I do -- probably more as I have to contend with severe light
pollution here.

May you always have clear skies and comfortable conditions!


From:	Dieter.Wolf@DNSint.com (Dieter.Wolf@DNSint.com)
read your interesting OO & LXD55/LXD75 report; thank you for it.
Bye the way, my LXD55's DEC housing is always on the left/west side too.
Dieter (Munich, Germany)
Mike here: But there are photos in the LXD75 manual and those arrows seem to indicate to put it on the East side. I have had the DEC housing on the West side on my LXD55 since I got it in November 2002. So 3+ years of working OK on the "wrong" side. Hence the controversy.
As to velcro, I planned to just add a 2" strip vertically to the top of each leg attach point on the base. I do have the soft side of velcro on the back side of the Autostar (from my LXD55).
Subject:	Re: LXD75 + Meade Newton 6" + autostar #497 (41E firmware) TERRIBLE PROBLEM!
Sent:	Friday, May 5, 2006 01:14:04
From:	Denis Ferrari (denis.ferrari@fastwebnet.it)
No improvememnts with 4.2 Ed, everything is the same...too slow tracking
speed, no need to touch dec (that's correct) even for hours.

I did and did again and reset again and did again CALIBRATE MOTOR and
after TRAIN DRIVES. Results : No changes , same problem!

I'm sad.

Thank you, I'm going to check the article...but, where's the article? n
your wesite?



Ok, I saw the article...anyway, these percentages are also functioning
for the tacking speed? Or only for manuale movements? If for only manual
movements..well my tracking very erratic speed problem is not solved.

Thank you anyway,
Mike here: I'd be surprised if the tracking rate is still incorrect. Have you done the axis adjustments as suggested in the back of the LXD manual?


Absolutely yes, I did it and did it again...result : NO CHANGES IN THE

Mike here: Just out of curiosity, which one did you do?


All 4, no problems. But the "slow" tracking error didn't change.
Mike here: 4? I thought there were only two! One manual and one with the Autostar. I am picking up my LXD75 mount today but won't get a chance to really use it until my next trip to Oracle Observatory at the end of May (weather permitting). I am out of ideas until I get some experience with the LXD75.
Well, actually I do have one more idea. Do a one star alignment. Assuming the optical axis of the telescope has been properly aligned to the rotational axis of the mount, then this will align the rotational axis to the Earth's rotation axis. Once you have completed that step, do another alignment, either and Easy Two Star or a Three Star alignment.


Ok, I wait your news as soon as you can use your LXD75. I'm still
thinking I my autostar or mount have some problem. ...

Your're completely right...and it is exactly what I've always done with
my mount and scope. I repet, I'm convince there is some strange problem
in my mount or autstar aswel. In the meantime I'v sent the mount to the
Meade service assistance point nearest to my house and also, I've
ordered a LX90 GPS system.

Please, don't forget to advise me as soon as you have used your LXD75,
I'm waiting your news or ideas.

Thank you very much,
Denis Ferrari - ITALY

Subject:	LXD75 + Meade Newton 6" + autostar #497 (41E firmware) TERRIBLE PROBLEM!
Sent:	Wednesday, May 3, 2006 07:50:04
From:	Denis Ferrari (denis.ferrari@fastwebnet.it)
Hello, a month ago I've bought a new LXD75 mount (new model) + Meade
Newton 6" + autostar #497 (frirmware versione 41E). I'm quite keen in
astronomy and during all the days I tryied to observe the sky using
autostar I always had the following problems : tracking speed not fast
enough..I mean, that after I do a almost-perfet alignent (Easy mode)
every goto I do almost reaches the object into the 26mm or also 9mm
eyepiece, BUT the tracking in few minutes makes me loose the object as
if the tracking speed itself wouldn't be fast enough. Obviousily, I
checked the gearings of both RA and Dec motors and are perfectly
alingned, no big backlashes, no mechanical backlashes. Next, I did the
autostar reset many many times, the the calibrate the the train and
every time nothing changed. The telescope models set is of course LXD
55/75 N, the train has been done perfeclty every time, the plar alignent
is perfect and the mount is very horizontal. The very strange thing to
me is that every goto I do, rmakes me reach the object (saturn, jupiter,
moon, arcturus,..) very well, and with only very very few corrections I
can press Enter to syncronize the tracking. The motors run +/- the same
way, the same noise, with arrows the movements can be done quite
precisely, at every speed. The PEC is of, but I of course tried to do
the Erase, the the Train and then many Updates, but I see only small
improvements in tracking. Now, the point is, where I do wrong ?? And
why?? I'm very keen to find object in the sky manually, using a sky
chart, and now that I've passed to autostar everything to me should be
easier and much more funny...but still it is not. More, the batteries
are perfeclty charged (already change to use a regulated power supply
for Autostar but nothing changed). Also, the axes locks are very well
tighted and locked before I do the alignment, the motors seem to run
perfectly even during the tracking, that it's happening but not enought
fast on RA axis. Also, every time I do a perfect alignment I see that
the only axis I have to correct since my "slow" tracking spped is the RA
axis (right and left arrows on the auotstar keypad), no need to touch
the Dec axis, so I tink it means that the alignment I did was almost
perfect. Anyway, the maximum time I can keep an object in the eyepiece
(the focal lenght of my tube is 762mm) and the eyepiece can be an
Hyperion 5mm or Super PLossl 9.7 mm) is more or less 3/4 minutes
maximum, it's bad and absurd!! Of course if I disable the tracking speed
(setting the targets as terrestrial) it's very much worse. I want to say
that the tracking it's happening, bad but it's appening and I'm sure
nothing slips mechanically! Finally, the only way I ave to correct this
awful problem is to set the tracking speed as Custon (not Sideral) ad
set the maximum value this firmware allows me to write, that is +999. In
this way the problem riduces a lot more, and the tracking seems to be
very good, but still not perfect and not fast enough, I mean that in
10/15 minutes the objects still goes slowly out of the eyepiece, even
the 9,7mm eyepiece. Now, I'm very stressed and worried about this... the
last chance I have is to updatew the firmware to the newest one, that is
41dd I think. Have you gant any experienxe of a problem like my one?? Or
srange feedbacks about the firware 41E I have currently on my autostar
#497?? ...I'm quite disperate, I hoe you HELP ME! THANK YOU VERY MUCH!
Denis Ferrari - Italy
Mike here: I don't recall any specific problem like this with 4.1E but go ahead and update to 4.2Ed. See if that clears the problem. I suggest doing a RESET, CALIBRATE MOTOR, and TRAIN DRIVES following the update. If that doesn't cure it, check the article "Setting Percentages For Better Tracking" on the Helpful Information: Autostar Info page.

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Copyright © 2006 Michael L. Weasner / mweasner@optcorp.com
Submittals Copyright ©2006 by the Submitter
URL = http://www.weasner.com/lxd/feedback/2006/may06/feedback.html