Last updated: 31 July 2003

LXD55 8sc logo

This page is for user comments and information of a general nature or items applicable to all LXD55 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 set up like weasner's
Sent:	Thursday, July 31, 2003 16:41:41
From:	"KELLY CAFFEY" (kelcaf@msn.com)
I am going to purchase the LXD55 from OPT andI want it set up like
yours in your article.

Here is my question. Will I need to do anything to mount the 2" diagonal
m929 not covered in your article?

Also, what moon filter are you using?
Best regards
Mike here: The 2" diagonal just screws on. Nothing extra needed. I use the Scopetronix Moon Filter.


Thanks Mike. Much appreciated.

Subject:	Autostar 2.6EC
Sent:	Tuesday, July 29, 2003 14:05:35
From:	"Jim Redmer" (redmer@wideopenwest.com)
Someone in the yahoo groups, I think it was Gemmalady, said she found
2.6EC in your Autostar archives. I can't find it. Can you help?
Mike here: It is there. Check the Autostar Information page, then "Autostar Software Archive".


Sure enough! Sure seemed easy enough find. I do the same thing in
grocery stores :o)

Thank you.

Subject:	Which telescope should he get?
Sent:	Sunday, July 27, 2003 17:43:42
From:	"jennifer kincaid" (princess8675309@msn.com)
My husband and I purchased a Meade Schmidt-Newtonian telescope, and are
totally in love with it. My problem comes in that my 17 year old
neighbor boy now wants to make astronomy a hobby. He obviously loves
our telescope, but cannot afford it. My question is two-fold. 1) If he
would like to buy a telescope with go-to power for under $500, is that
possible? and 2) if so, which telescope would that be? Thanks so much
for considering our questions, and sharing your expertise.

Jennifer Kitchens
Mike here: The ETX-90AT comes close to the price, including the Autostar and a tripod. The ETX-90 is a good choice at that price. Alternatively, there are some similarly priced but larger LXD55 models or even the DS models. Both can use the Autostar GOTO handcontroller. So, beyond the price, he needs to decide whether portability is important (the ETX-90) or whether a larger aperture would be good (LXD55 or DS).
Subject:	Re: Autostar Error
Sent:	Sunday, July 27, 2003 11:07:06
From:	rseymour@wolfenet.com (Richard Seymour)
To:	jedmo@hotmail.com
I wonder...
 when you enter your TIME is it showing "PM" after the time?

If not, then you ahve the Autostar in "24 hour" mode, and if you
tell it 8:00  you are saying 8 AM. 
 12 hours, (or 6 months of star positions) off.

Try either telling it 20:00:00 (for 8 pm),
or use the right slew key to position the cursor -after- the
final digit, and use the scroll up/down keys to cycle a PM into view.

good luck
> Yes, the time that I input was the correct time with pm at the end.

OK... we'll escalate:

Ensure that your Telescope Model is correctly set.

Which version of firmware are you running?
( Setup > Statistics > [scroll up]  gives the FULL identifier)

Where is your site?

Ohh... an LXD55 .. have you double-checked that the barrel is not
-backwards- in the mounting rings?  (a fairly common mounting error)

have fun

Subject:	LXD-55 GEM question
Sent:	Saturday, July 26, 2003 21:18:01
From:	Joe Lippencott (lippen@rci.rutgers.edu)
I am trying to remove the plastic cover for the R.A. motor assembly for
general inspection and lubrication. I can't seem to get the darned thing
off. I have removed the two (tiny) sheet-metal like black screws holding
the two halves together, but there seems to be something keeping the
halves very firmly attached at the connector/control panel side. I can't
find anything on the outside that's accessible that will release this
side. There seems to be something internal holding the two halves
together. I had no trouble with the Dec. motor assy. cover (there are
four screws there and everything is obvious). I have been a
machinist/mechanic for my entire life and I can't believe the people
that don't even own a complete set of hex keys (allen wrenches to some)
or don't know the proper terminology for 1/16 (2/32 ????) can just "pop
the cover off". Is it possible there are those little plastic clips
molded into the covers that I have to pry apart? I'm afraid to force
them open since any evidence of tampering will void my warrantee. Has
anyone, that you know of, provided any kind of disassembly procedures
for this mount? Any help would be greatly appreciated.

Joe Lippencott (SN-8)
Mike here: See the article "Fixing a Slipped RA Gear". I suspect you need to remove the large bolt in the GEM head just above latitude adjustment (see photo in the article).
Subject:	Re: Autostar Error
Sent:	Saturday, July 26, 2003 08:32:46
From:	"Josh Edmondson" (jedmo@hotmail.com)
Sorry I haven't gotten back to you with an update before now. I had
written you earlier about a problem with the Autostar on my new LXD55
AR-6 refractor. After completing the initialization with the correct
date, time, DST, location, telescope type, calibration and drive
training (both axes), the alignments were still WAY off. I don't know
what I'm doing wrong, if anything. So after several restarts (not
resets, although I did a reset before last nights session), I was
getting pretty frustrated. However, I noticed that the alignment stars
that Autostar was choosing were in wintertime constellations, Rigel,
Betelguese, Castor, Pollux, etc. So, I figured I would try one last
idea before going home and that was to change the date from July to
January. If it thinks that July is winter then maybe it would think
that January is summer was my reasoning. This was with one star
alignment, I centeredPolaris using the mount controls not the keypad,
hitENTER, it begins slewing to Arcturus which was high in the western
sky at that time, I centered the star, hitENTER, alignment successful.
I was skeptical because I had been getting these successful messages all
night. SoI choseAntares, hit GOTO and it put it in the FOV of the
26mm eyepiece. Same thing with Deneb. I chose Mars and it was way off.
So, it works like that with deep sky objects but not with solar system
objects. Have you ever heard of this type of problem before or have any
idea howI can correct it? Sorry thisis such a long message, I just
wanted to cover everything. Feel free to post it to your website.


Mike here: This is an odd one! Never heard of this happening before!! Sounds like maybe something is corrupted. Reloading the Autostar software is probably required.
Subject:	astrophotography
Sent:	Saturday, March 23, 2002 13:04:55
From:	"Joao Carvalho" (jcarvalho@fs.fed.us)
I would like to ask you how do you do astrophotography with the LXD55
mount (SC-8).

You use a CCD or a digital camera.

How do you correct PEC ?   and how do you track exactly the object ?

Thank you
Mike here: See the Helpful Information - Astrophotography page on my LXD or ETX sites. Lots of info there. The Autostar does not do PEC.
Subject:	congratulations for your site
Sent:	Wednesday, July 23, 2003 08:37:13
From:	Philippe Carrette (pcarrette@yahoo.com)
I'm Philippe Carrette,belgian,living and teaching in Mexico for ten
years. I just received yesterday my 8sc lxd 55 from the mexican importer
kosmos. I hope to be a new fan of your site and keep in contact with you
for further infos.



Subject:	LXD55  or  CG5-SGT  ?
Sent:	Thursday, March 21, 2002 21:09:44
From:	"Joao Carvalho" (jcarvalho@fs.fed.us)
I have a Meade SC-8 tube (with a old LXD500 mount)   and I  am balanced
between  the  LXD55 and the CG5-SGT  mounts.

Which one do you suggest me, and why  ?

Thank you
Mike here: I personally have no experience with the Celestron mount so can't comment.
Subject:	lxd 55 French
Sent:	Saturday, July 19, 2003 15:40:59
From:	"Patrice Hess" (baph2@tiscali.fr)

Jai un LXD10 , cest un trs bon tlescope.

Mal grs tout jai eu des petits incidents.

Un jeu dans les engrenages des moteur me fausser le pointage jusquau
jour o le tube cest retrouv point vers le sol.

Les pignons taient desserrs.

Je recherche la version Franaise pour lautostar.

Jai ralis un systme de mise au point lectronique, a marche bien.

Sinon, le LXD est super.



Mike here: I was able to translate most of your message. You might be able to get a French version of the Autostar from Meade's international locations. Check the Meade web site for more information. As to unusual occurrences, check that you have the right telescope model selected in the Autostar and that you have done a CALIBRATE and TRAIN DRIVES (both Right Ascension and Declination). If they are correct, check the gears for slippage (see the article "Fixing a Slipped RA Gear" on my LXD55 Site.


Je te donnerai la modification que jai apporter au pointeur polaire
pour eviter quil reste allum.


Bonne nuit!! de Marseille


Subject:	lxd55 question
Sent:	Saturday, July 12, 2003 17:25:46
From:	"James Gilnack" (jgilnack@earthlink.net)
Hi, Nice web site. Its very informative.

Just a quick question. Should I buy the 8" or the 10" LXD55 ? I ask
this because I read that some people think the 10" is too big for the
mount. I'm going to get the better coatings in either case.

Also, once you have set it upmany times ... whats the setup time?

James Gilnack
Mike here: Yes, there have been some reports that the 10"SN is a bit much for the mount. But beyond that, there is a definite difference in the two telescopes: one is a Schmidt-Cassegrain and the other a Schmidt-Newtonian. Focal lengths is different for the two. So which one, SC or SN, you should get will depend upon what you want to do with the telescope. Setup time will only take a few minutes, maybe a max of 5, depending upon how careful you want to be.
Subject:	re: Gears (LXD55)
Sent:	Friday, July 11, 2003 20:57:20
From:	rseymour@wolfenet.com (Richard Seymour)
To:	shanea@danka.com.au
Loctite is, indeed, a superglue-like material.

It's specifically an "anerobic cure thread lock compound".

You put a -tiny- drop on the threads of a screw you don't want to come
free... then screw it in (so it's applied -before- assembly).
If cures when it cannot reach air. (that's the anerobic part).

Meade uses similar stuff (theirs is usually reddish).

You can find similar compounds at automobile machine shops and
aircraft maintenance facilities.

In the US, Loctite is commonly available in three grades, denoted
by color:  Blue is the "gentlest"... and what we would use for the 
set screws on the gears (since you might -want- to take it apart again).

Red and Green are more permanent.  Avoid in this application.

have fun

Subject:	Meade's standard issue 26mm Super Plossl Eyepiece
Sent:	Saturday, July 12, 2003 02:50:58
From:	doug canard (dcanard@cswnet.com)
Frankly, I didn't like it. The eye relief was horrible for me because I
have to wear glasses. I could barely see half the field of view even
with the rubber cup thingy folded down. The 26mm Plossl that came with
my used ETX 90 is NOT like that. I'm not sure, but I think it may be the
older Series 3000 EP.

I noticed on the EP that came with my LXD 55 AR-5 that the lens is way
down there from the lip that holds the rubber cup. I unscrewed the
barrel off the EP which revealed another barrel-like device that I
unscrewed, it holds the PLOSSL lenses snug. Once I removed that and the
lenses , I used a bandsaw to chop off about a quarter inch of the excess
on the top of the EP that was keeping me and my glasses from getting
close enough to the top lens for a full field of view. Be carefull and
don't chop off too much. Yoiu will notice a ridge inside of the main
barrel that the top lens fits against. Do not chop past this point or
the EP is a goner.

A little buffing with a buffer wheel to smooth out the rough spots where
I cut, reassembling of the lenses and barrels, and I can now see the
entire field of view while wearing my glasses. Big improvement, and it's
not a bad EP either, once I enabled my eyeball to get closer to the
lenses. I've heard that the other eyepieces included in the 100 dollar
deal are even worse for eyeglass wearers {at least the ones more
powerful than the 26mm}. Is this why they are going so cheap?


Subject:	Worm Gear backlash on the LXD
Sent:	Saturday, July 12, 2003 02:30:01
From:	doug canard (dcanard@cswnet.com)
A few days ago I noticed my batteries were going low way too quickly
compared to when I first used my LXD AR-5. I had tightened up the worm
gears by adjusting the three allen bolts and realized that although I
had reduced quite a bit of backlash, I may have introduced too much
friction between the worm gears and the main gears on the R.A. Dec
shafts, causing the motors to require too much amperage when slewing and
tracking. I remember having to bump up my tracking speed to positive 113
percent for accurate tracking over long periods of time.

In the hopes of putting the worm gears' backlash back to factory specs,
I called Meade's Customer Service, and was informed that there is no set
factory standard for the amount of "slop" and backlash. It is more of a
feel thing while checking the current drain on the motors as they slew.
So, I readjusted the three allen bolts on both worm gear assemblies back
to where they moved freely with about one eighth of a turn of backlash
with minimal resistance for turning of the gears once the "slop" was
taken up.

I found that a good RESET, RECALIBRATE, and RETRAIN  gives satisfactory
ALIGNMENTS do not do as well for some reason. Not only that, but the
motors sound somewhat quieter when slewing, and my batteries are lasting
longer than before. Backlash that may seem problematic or excessive
really isn't if the drives are trained as precisely as possible, I've
come to discover. I still had to bump up my tracking speed to positive
35 percent for long-term tracking. My R.A. drive was undertracking when
I first received this scope ,and 35 percent is a lot less than 113 , so,
I guess having some backlash is exactly how the mount was intended to be
from the factory.

It was just that loose R.A. drive gear all along that had messed up the
accuracies of my GOTOs. If the brass and silver  gears are tight on the
shafts and a decent RETRAIN is accomplished the mount should do OK even
if the worm gears may seem to be too sloppy. I found that experimenting
with the R.A. and Dec percentages in the TELESCOPE sub-menu under the
SETUP menu will decrease some of the time delay caused by backlash being
taken up when slewing back and forth at slower speeds.

In a nutshell: amount of slack in each mount's worm gears may vary.
Meade has little elves that know exactly how to adjust each mount
individually according to feel and test equipment. {not really, the
elves that is}

Mike here: I always default to doing 2-star alignments (hold over from my ETX experience!!). The times I've remembered to do 1-star I've been happier with the GOTOs!
Subject:	Digital camera recommendation
Sent:	Wednesday, July 9, 2003 07:53:06
From:	Gailwov@aol.com
I'm wondering if you or anyone out there has thoughts about a specific
brand/model digital camera that works well for occasional
astrophotography as well as other all around use. Not looking for world
class performance. . will settle for acceptable. Here's the catch. .
would like to find something under $300. Thanks.
Warren Vaughan
Williamsburg, VA
Mike here: See the Helpful Information - Astrophotography page on my ETX Site. You'll see that almost any digital camera can be used for some types of astrophotography. I have used a Casio QV-10, Ricoh RDC-4200, but now use mostly my Nikon Coolpix 995 but have recently used a Casio Exilim.


Thanks for getting back to me on this and for the time you devote to
your website. I should have asked before but are you aware of a
universal camera adapter for the LXD55 and, if so, where I could get
Mike here: See the Accessory Reviews - Astrophotography page; several are shown there.
Subject:	Gears
Sent:	Monday, July 7, 2003 21:03:01
From:	"Shane Allen" (shanea@danka.com.au)
Have decided that the next time I take off my dec motor I will do
something more permenant than just tightening the worm gears. I have
been reading on the LXD55 Portal that some people are using a product
called Loc-tite as a means of securing these screws in place. I'm not
familier with this product. Could you please tell me what it is, and if
it is an effective means of solving gears coming loose.


Shane Allen
Mike here: Loctite is a glue-like product that is available at hardware stores. It basically glues the item in place. Personally, I don't like it but others certainly do.


The old super glue trick, hey.  Would you apply it on the top of the
worm screw to prevent it coming out or on the actual drive arm that the
gear goes on?
Mike here: Personally I have no opinion on where to apply it. Personally, I wouldn't apply it all.
Subject:	Autostar Error
Sent:	Monday, July 7, 2003 11:24:58
From:	"Josh Edmondson" (jedmo@hotmail.com)
I just recieved my LXD55 AR6 last week and took it out for observing a
couple of nights ago. Followed the instruction manual to the letter (I
thought) and when it came time for the easy alignment, the stars that it
chose to align on were way off, like 20-25 degrees or more. So I went
ahead and centered them, hit enter, "align successful" message displays,
but all GOTO's were way off as well. Once it even pointed the scope at
the ground. I called Meade this morning and the guy says he doesn't
know what's causing it either, but says I might try lowering the
percentages to see if that might help. This is my first computerized
scope and I don't know if I did something wrong or I have a faulty
Autostar. Any suggestions would be greatly appreciated.


Josh Edmondson
Mike here: The obvious questions: Have you set the proper location and Daylight Savings? Have you set the proper telescope? Have you done a CALIBRATE and TRAIN DRIVES (both axes)?
Subject:	cudos to your website on the LXD 55
Sent:	Sunday, July 6, 2003 22:10:54
From:	"Walter  Ness" (walter.ness@3web.net)
Me again.

I just wanted to thank you for posting such great info on your website
on the LXD 55. Your links are invaluable. The one that I can relate to
is the "Fixing a Slipped Right Ascension gear".

I just received my LXD 55 less then a month ago and its been plagued
with problems. From the OTA tube filled with debris (- foam rubber from
the primary mirror clips and metal shavings from the screw holes) and
having to carefully clean it out (e-mail I sent you forewarning others
regarding this issue).

The latest problem I am working on is a problem I discovered with my
mount.What tipped me off to a problem was Icould never getproper
alignment.As I was operating the scope, it would say on the Autostar
that it was slewing, yet it was not moving (the mount moving the
scope). When I would attempt to move onto a object using the slew keys,
a number of times I could not get the left arrow key to work. The scope
would not slew at speeds up to x64 for that key. Above that speedit
would start to work. It was very strange. So I took it back to the
place I purchased the scope (not going to mention any names to protect
the innocent) stating there was a problem with the mount, they ran tests
that they called Mach tests on stars and claimed it was working fine.
These tests were not of course under the night sky but were
simulations. Representatives at the store offered their services for a
fee to show me the ropes with the new scope. I was about to take them
up on their offer (swallow my pride and admit defeat) but decided to
investigate the problem a little further. I mean I know I am not a
genius but I did own an ETX 125 and was able to align and work with it
without any problems.

I came across the above mentioned article you posted "Fixing a Slipped
Right Ascension gear".After lookingat the articleI decided topop
off the covers covering the mount's drive gears to take a look at them.
Well, the Dec drive was solid so no problems there. Popped off the
Right Ascension drive cover to look at its gears and "BINGO". Staring
at me was a very sorry looking non-meshing gear assembly for the RA
drive. I went to work quickly (or for me at least). Took out the only
screw/bolt thing holding on the RA Drive motor along with the mount's
Control panel. Now I have a problem with this. Why not have 2 screws
holding the Drive and Control panelto the mount to allow for a more
firmer and secure fastening. The problem with having only one in the
center, if the screw or bolt loosens then you have problems.

Anyway, I take the screw out and I'm in. I loosen the 4 screws on the
bottom that hold the RA motor in place in the RA motor gear box/control
panel and push the motor up more to move it closer towards the silver
gear on the mount to obtain a better meshing. After doing this, I
examined the 3 screws on the mount. These seem to control the tension
of the WORM gear for the Right Ascension movement of the GEM. They were
loose and I found that this affected the performance of the RA motor and
Right Ascension movement. I tightened and balanced them so that I could
easily turn the scope on the mount by turning the silver gear (on the
mount) for the RA motor meshing with my hand. Now the silver geardid
turn but I also noticed the Silver gear was loose as well. There was an
incredible amount of play before it would turn the WORM and scope in the
RA direction. I looked at the article you posted (mentioned above) and
of course it mentioned a problem with the loose Sliver RA gear. In the
article it was mentioned that a 2/32" Allen key was used to tighten this
gear. I am still trying to find one. If that's what it is. I think I
will phone Meade and ask them to send me one or attempt to get some
assistance from the local Radio Contol Hobby store since the gears and
motor look like the RC type. The problem with this gear set up is that
this RA silver gear has to turn the main bulk of weight via the WORM
gear and the method of securing it to the drive shaft really is a poor
design. What I am going to do and what I would recommend is to ensure
that the silver gear is in the correct position on the drive shaft, get
the key and tighten the screw that holds the gear to the shaft. Tighten
hard enough to leave a mark on the shaft. Take the gear off by
loosening, then using a small drill bit and variable speed drill, make a
small indentation where the screw fastens. The problem with having the
screw fasten to a smooth and hard surface (in this case, the drive
shaft) is that it can't get a firm clasp or holdand will slip. Making
an indentation or divot with the drill bit, lets you place the screw in
the indentation and gives the screw a better hold and prevents it from
running off the smooth brass surface.

So I have gone through a hell of a lot of pain. Been looked at like I
don't know what I am doing and for what. The OTA problem was bad enough
and I was not impressed that the scope OTA was QC passed with debris in
the tube that had gone un-noticed at the Meade plant. Not to mention
the fact that the debris was a Meade installation issue at the
California plant. Also, that the mount was made in China and was put
together extremely badly. I noticed that there was no QC sticker on the
mount. Which leads me to thinking that it was not even checked. At
least I don't believe they put an LXD 55 10" SN scope on it loaded with
the counter weights. I like the fact that the Chinese can make things
cheap and as a result, we can enjoy a cost reduction on consumer goods
(like the scope) but they sure can't make things like Taiwan or Japan.
If you can remember Japan in the early days. Cheap products but lousy
quality. They changed that around. I don't think China will be able to
match them. Anyway, what I was about say was I would rather pay another
few hundred dollars and get the quality I think we all deserve. Funny,
I had some problems with my ETX and it was made in Mexico. More horror
stories from 3rd world manufacturing of goods.

I have purchased two Meade GOTO scopes and can safely say this LXD will
be my last. Celestron, here I come.

Again, thanks for the time and information Mike. Without people like
you supporting these products and helping owners resolve issues and
problems, Meade would be in sorry state.

Walter Ness
Oakville, Ontario

Subject:	autostar MUF problem on sn-6
Sent:	Sunday, July 6, 2003 10:56:29
From:	"John Paladini" (jpaladin1@rcn.com)
I recently recieved a SN-6 with autostar

when trying to align easy, one star or two star I get motor unit
failure using battery pack batteries are new passed power check I
balanced scope as best I can

Inspected gears under cover -- looks- good no play or loosness I did
what you suggest reset , calibrate, train -- but still no luck (those
functions seem to work)

can only use drive in 'astronomical' track mode (that works) 
slew arrows work when pressed by hand 
version is 26Ec

telescope starts to move , does move, but then error occurs does it's
little testing motor dance and then starts from initial point

Any Ideas before I must call MEADE

P.S. -- one more point , question
I notice speed control 2x, 4x .... works only for RA not DEC is that
Mike here: Speed control SHOULD work for both axes. If it doesn't then I suspect something is wrong someplace. You might try upgrading to the current ROM (2.6Ed) from Meade's site.
Subject:	2/32" hex key doesn't work
Sent:	Sunday, July 6, 2003 10:43:03
From:	Dan Kahraman (ishtar66@primus.ca)
I too have a problem with the silver gear on the RA shaft being loose
and not engaging the brass gears.

My problem big that it seems right now is that the 2/32" allen key seems
too large for the set screw.

What should I do? Is this metric? If so what size?

Exasperated with my Meade SN10"

Dan Kahraman
Subject:	0.050" or 1/20" hex key NOT 1/16"
Sent:	Sunday, July 6, 2003 12:05:26
From:	ishtar66@primus.ca (Dan Kahraman)
Please correct the error on your web site. The set screw needs an 1/20"
allen key not 1/16" or 2/32".

I am referring to the size of the screw on the silver gears for the RA

Unless there are two sizes used...

Let us all know.

Dan Kahraman
Mike here: Thanks for the reports. That's what I measured. But I was using an old tool for the measurement. It could be off at that small size.


A lot of the posters on the yahoo groups site for LXD55 'scopes are
saying 0.050" or 1/20" . Certainly  seems to be my experience. Now I
have to purchase that key.


Subject:	How do I tighten up axle play. (slop?)
Sent:	Thursday, July 3, 2003 12:16:48
From:	Donti@aol.com
I have been searching through the postings at the LXD55telescope group
site, OPT's motherlode and your site looking for some help as to how to
tighten up a bit of play in the DEC gearing. Since I'm new, let me
describe my problem: The axle with the steel gear that's left on the
mount when I removed the motor turns about 1/8th of a rotation before it
engages the worm drive. In either direction. There's no movement in the
axle from end to end. I uncovered this problem when I was performing the
fix on tighting the set screws. I've also, re-trained the drives but the
problem is still there.

I've read postings on the three screw for adjusting the bite on the worm
gear and about the end brass nut on the axle. But I haven't seen
anything on this axle movement. Or maybe I've read so much and it's all
a blur now.

How can I massage this play out. It's frustrating when using a
high-powered eyepiece and slow slewing speed to center an object as it
takes a few moments/seconds for the ota to move. Thanks in advance.

Don Soria
LXD55 10"sn w/UHTC
Mike here: Physically, I don't know. Have you tried adjusting the percentages in the Autostar?
Subject:	Calibrating and Training after Reset
Sent:	Wednesday, July 2, 2003 19:42:16
From:	doug canard (dcanard@cswnet.com)
Should I train my drives before calibrating after I reset the autostar
or vice versa? Does it make a difference?

Also, the worm gears on my newly -arrived LXD 55 AR-5 are very sloppy
with lots of slack. What is the correct amount of backlash I can have
before the worm gear gets too tight from adjusting the allen bolts? Does
that make a difference in accuracy?

Finally, the ra and dec gear boxes were wiggling when I slewed the
scope. I tightened the allen bolts that hold them to the mount. This led
me to suspect that maybe the worm gears may not of been adjusted
correctly at the factory. The brass gear in the ra gear box that turns
the silver gear also had a lot of slop in it. I tightened the set screw
as much as I could , but I couldn't get it to tighten all the way. So, I
superglued it onto the shaft. Did I just void my warranty?

Mike here: The sequence is RESET, CALIBRATE, TRAIN. Don't overtighten the locks; if you are pushing on the OTA to determine "backlash", don't do that either. Use the Autostar for slewing. If you want to tighten up the delay you can adjust the percentages in the Autostar. Were the setscrews in the gears set against the flat side of the shaft? I can't speak for Meade but I would hope that wouldn't void the warranty. After-all, they made it easy to get to the gears.


I removed both gear boxes and turned the worm gears by hand. SLOPPY! I
could turn them almost a quarter turn back and forth. I adjusted the
three allen bolts until I have a backlash of no more than the distance
between two gear teeth {I'm guessing no more than a couple millimeters}.
They are a little harder to turn but not by very much-- No more than the
resistance you would feel on a mount with nice, tight,manual slo mo
controls.  And yes, the set screw was flat against the shaft, it just
wouldn't tighten enough, and stripped out my only allen wrench that
would fit such a small screw. I suspect a defective set screw to begin
with. All the other gears are fine. {including the ra gear now that it
is superglued onto the shaft}. I can always return the worm gears back
to their original sloppiness if what I did was a no no. It's just that
my GOTOs weren't all that great as advertised.

And adjusting that polar alighnment scope-- don't even get me started.
Tedious tedious tedious. But it is now almost perfect. As is the
orthogonality of the OTA.

Speaking of the OTA: It has exceeded all my expectations for the price.
And the finder scope actually focused and adjusted OK. The OTA and all
its attachments truly shine. The saddle mount is A-OK in my book.

Time to go outside and RESET, RECALIBRATE, and RETRAIN. After looking at
how the decoder wheels work, I now understand the necessity of a good
retrain. I still do not understand what the calibrate function actually
does. All the manual says it that "calibrate" tests the motors. There
has to be more to it than that if calibrating before training is

One last thing...when I bought my scope at the dealer , the first thing
I noticed were these big bold letters on the boxes that said "MADE IN
CHINA". I thought these scopes were made in Irvine, California. That
does explain the relatively affordable price for all the neat
capabilities , though....

Thanks for the advice.

Mike here: Assembled in Irvine is more precise for some components.
It looks like I may actually get to use my LXD55-8"SC tonight for the first time in over two months! Been fogged out, clouded out, and away from home just way too many nights!


I've heard that So Cal is notorious for being cloudy during June. It's
looking great here in west Arkansas. The Milky Way is glowing nicely.

Here's the update after I just set up and did some testing after
reseting, calibrating and training. Declination is spot on! However, the
R. A. was lagging. Each time I slewed to another object it would lag
even more ever so slightly. I would reslew with the {right} slew button
and synchronize. Then I remembered a problem from a few nights ago: my
mount was horribly undertracking {this is before I disassembled the gear
boxes,therefore, pre-existing problem}; I customized my tracking speed
until a factor of positive 113 percent kept objects perfectly centered
for a decent amount of time in either the western or eastern part of the
sky {that must mean the scope is well balanced?}. Has anyone else had to
adjust their tracking speed so drastically? Sounds a little excessive to
me. Results may vary?

So, I'm theorizing that if the tracking speed is off by too much, the
autostar thinks it's somewhere when it gradually undertracks {or
overtracks} and ends up ,in actuality, somewhere else, and will end up
with compounded positional errors in the R. A. axis over a considerable
amount of time? I have noiticed that my particular mount is more
accurate when "quit slew" is activated. Strange.

This technology is too new to me at this moment. I'm still getting used
to NOT having to squint at the coordinates for objects with a red light,
and manually swinging a scope around the sky as I forget to update my
setting circles, and have to start the process all over again. I may get
happily spoiled from  these wundergizmos doing all the work for me.

Those motor drives sound like a can opener on steroids. Ear plugs may be
in order.

Enjoy the sky,

Mike here: There are lots of variables in GOTO accuracy: TRAINing accuracy, physical alignment accuracy, Autostar alignment accuracy, condition of the gear train, alignment of the optical and mechanical axes. Have you aligned the optical axis per the manual? That might be the culprit. I was out tonight and found myself having to SYNC when slewing to widely separated portions of the sky; I suspect I may need to do this as well.


Yes, I have the optical axis aligned according to both techniques in the
manual , plus, I triple checked by comparing to what was in the polar
scope's crosshairs on a terrrestrial target after painstaking alignment
of said scope a couple of days ago. I was getting consistent GOTOs with
accuracies ranging from almost dead center, 15 to 30 minutes from center
in the 26mm ep on average , and just inside the fov at the worst  before
I called it quits for the night a few minutes ago. I will assume the
credit goes to taking out some of the slop in the worm gears {not the
round  silver gears but the whole worm gear assembly itself}, fixing
that lose R.A. gear, and a good calibration and training.

I had to move the mount so I could see Mars above some trees , and I
couldn't see Polaris because of other trees to the north, yet, a dead
reckoning with a protractor, a compass, and a little tweaking of the
azimuth by dec drift  method before realigning by two-star method seemed
to do OK. Customizing the tracking speed to positive 113 percent again
kept Mars in the fov at high magnification {about 300X} for views of the
polar ice cap and some land features. A quick star test showed almost
textbook Airey discs. I'm really impressed with this 5 inch refractor,
I'm glad I opted for it instead of the 6 inch newtonian {which I was
told has an almost 40 percent secondary obstruction. That seems rather
drastic for a little six-inch primary IMO}. I have a solar filter
intended for a six-inch Newtonian that I'm sure I can rig onto this Ar-5
for some solar viewing today.

Once I started getting familiar with the Autostar I found it to not only
be fun but rather educational when I paused to pay attention to the
words scrolling across the display screen.

I hope clear skies hold out for you and everyone for the rest of the
holiday weekend.


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