tracking vibrations

[callaway19662003]

Hello,

Whenever my scope is automating tracking and object I will get just a little bit of vibration. About every 10 seconds it will move just a bit and when doing so the object is blurred from the vibrations? Is this normal and what can I do to minimize or stop it?


Thanks,
Brad

[Mark Sibole]

what scope model?
Visual or when imaging?

Mark

[callaway19662003]

Mark,

LX90 8" GPS. Visual.

Brad

[callaway19662003]

I just got off the phone with Meade customer service. They want me to send it back so they can repair it. They said it would take a few months before they could get it back to me. I was really hoping that this was just a minor problem that could be resolved easily. I am so dissapointed... . I waited years to get a real good scope and this is really my worst nightmare.

Brad

[WoodDragon]

Months to get it back, I've nad my lx90gps a couple of months and
no problem but with repairs taking that long I consider that unforgivable
for a company to do bussiness in such a matter. I'm really thinking about
going ahead and selling it now while I can still recoup most of my investment
and just going back to my old scope,

WoodDragon

[Mark Sibole]

Brad
I can imagine with the move of the facilities it would take a bit longer.
Does the scope make any noises when this happens?
Have you trained and calibrated the drives?

Mark

[autostaretx]

These vibrations are becoming a too-common topic in the LX90 Yahoo group, too.
http://tech.groups.yahoo.com/group/lx90/

In the early (2002) release of the LX200gps there is/was a programming error
in the PIC chips on the motor cards which caused a similar symptom.
(the motors would -stop- for 6 milliseconds if there was a speed change,
and Alt/Az motion gets speed updates once per second).  After mid-2002,
the LX200gps cards no longer had this problem (and had an updated Pic
part number).

What is puzzling about the sudden upsurge in LX90 vibrations is that it's happening to scopes
which did -not- exhibit it before.. so that lets out the Pic programming.  Some have been caused
by worm gear misalignment, some have been fixed by motor assembly replacement (which
also received gear re-alignment, so there may have been a common thread there).

At certain positions in the sky, the Alt motor is asked to turn -very- slowly... and if the
gearing has excessive drag that may cause it to bind and release.. and those releases
are the source of the vibration.   If you're mechanically inclined, you could open the fork
and inspect/assess the gear meshing. 
An alternate to Meade's repair service is Dr Clay Sherrod, as described here:
http://www.weasner.com/etx/techtips/tuneup_service.html

good luck
--dick (whose LX200gps goes "tick tick tick" at certain positions)

[callaway19662003]

Brad
I can imagine with the move of the facilities it would take a bit longer.
Does the scope make any noises when this happens?
Have you trained and calibrated the drives?

Mark

Mark,

Yes the noise is coming from inside the forks. It's like a clicking sound. It's sometimes worse than others and when it happens the image in the eye piece shakes for about 5 seconds. I estimate for every minute, it shakes about 20 seconds. I noticed it the first night but I thought that maybe I just didnt have something tight. I double checked and have trained and calibrated the drives. Since it has been less than 30 days since I have bought it, I called telescopes.com and they are going to send me a replacement. I like everything else about the scope and I hope that my next one is perfect.

Brad

[Mark Sibole]

Brad,
Im glad they are going to send you a replacement.
Read bac to Dicks post.
He is very knowledegable in these scopes.
Keep the info for future reference.

Regards

Mark

[autostaretx]

Another (two, actually) instances of ticking/vibration in new LX90s...
happening to  Mike Weasner:
http://www.weasner.com/lx90/second_first_light.html

One take-away lesson is: buy from a Dealer who's willing to exchange a sick scope...

I feel Meade's "dead fresh out of box?  You get to ship it to us  on your nickel
and then wait an indeterminate time for repair" "Warranty" is woefully inadequate
(and may violate "performs as advertised" consumer protection statutes).

One ticking scope is anecdotal.  Three or four begin to approach statistical.

good luck
--dick

[callaway19662003]

Another (two, actually) instances of ticking/vibration in new LX90s...
happening to  Mike Weasner:
http://www.weasner.com/lx90/second_first_light.html

One take-away lesson is: buy from a Dealer who's willing to exchange a sick scope...

I feel Meade's "dead fresh out of box?  You get to ship it to us  on your nickel
and then wait an indeterminate time for repair" "Warranty" is woefully inadequate
(and may violate "performs as advertised" consumer protection statutes).

One ticking scope is anecdotal.  Three or four begin to approach statistical.

good luck
--dick

I am starting to get a bad feeling about this now. I always seem to get screwed over and I hope this is not another one. Dick, thanks for all of the info.

Brad

[autostaretx]

On the bright side: historically, Meade *has* worked things out with conditions like this.
Having a dealer the size of telescope.com or OPT working on your side is very good,
they can get Meade's attention and action moving faster than having individual reports
trickling in.

But if it's a recent systemic error, you may have to wait (with a mostly functional
(except for the tick) scope) for them to sort it out and -really- correct it.
It may only happen to scopes asssembled on a certain day, and you and Mike
might just have the bad luck to have one of -those-.  The week later's
production could be fine... so i wish you the best of luck with the replacement,
and we're all avidly awaiting to hear how it goes.

Be aware that an Alt/Az scope -is- going to have some places in the sky where it is
almost -impossible- to avoid some effects caused by the motors trying to spin very
very slowly.  99% of the sky may be great, but there -will- be places where (if you
-really- check) there may be ticks/vibrations.   It's simply due to the compromises
required to -generate- Alt/Az motion trying to follow a sidereal sky with a drive system
costing less than $50,000.
If it bothers you at that spot, just wait a few minutes and the target will move to a
"better" spot in terms of the demands upon the drive.
Or mount the scope on a wedge (Polar mounting), and the issues disappear by
removing the need to operate two motors at continuously varying rates of speed.
On the wedge, the RA motor runs continuously at one speed, and the DEC drive
only moves during GoTo's.

have fun
--dick

[callaway19662003]

Hello,

I just received my replacement and this one is worse than the first. Now I am really frustrated and not sure if I should just give up and return everything back.

Brad

[autostaretx]

Opinion follows:
Although four to six reports is still possibly "anecdotal"
versus "statistical", there appears to be a problem with
new LX90's.   What i'd recommend (for the people unwilling
to open the fork and attempt worm-mesh adjustments) would be
to get on the phone with Meade and -escalate- it to -Meade-
paying the freight both ways to fix the sick-from-new scope.
New buyers should -not- be faced with an immediate $100 to
$200 (for LX90) shipping impact when -multiple- new scopes
demonstrate the same problems.

Meade should proactively just -offer- free inbound shipping
for new LX90's.  They may have had (or, dread, still have) a
production problem which they can (did?) resolve, but they'd
do a -lot- towards regaining customer loyalty if they 'fessed
up to it and "made it good".

In both your (telescope.com) and Mike Weasner's (OPT) case, the dealer
has been willing to eat the expense of shipping a 2nd try.
The dealers are going to stop doing that when they find
-all- (or a significantly large percentage) of the product
requiring replacement, with those replacements also being faulty.

For those folks willing to -work- on their scopes, inspecting
the worm area for alignment (worm shaft centered and parallel
to tangent of driven gear) and mesh (not too tight!) might
actually -fix- the problem.  This seems to be showing up
in new LXD75's (shims missing, too tight).

Yeah, you shouldn't have to -do- that, but if you'd prefer
to have a functioning scope than spend time packing and shipping
to Meade, it's the approach i'd take.  (it has the down-side of
Meade not seeing -all- of the scopes with the problem, so the
corporate mind thinking "it's not -that- bad", but that's the
coin-flip one has to accept.. although i suppose you could send
them a bill for your time)

good luck
--dick

[Mark Sibole]

It may just be a simple fix of tightening the 2 screws that hold the assembly to the base.
I had one a while back where the screws that hold the motor on the base were loose as some one didnt tighten them up.
Its a very simple thing to check and it beats sending scopes back and forth.

Mark