Meade LX90 Goto not tracking!

Draco (Draco) · #1 09-04-2014, 08:04 AM

Hi all

I have a 10" Meade LX90 ACF. Last night I took it out to view mars and wow what a sight it was. One of the poles was whiter than the other, though smudgy, I assumed it to be the ice caps.

Initially I used a 30mm eyepiece and though it was a less magnified image, things were still quite clear.

Then I changed to a 10mm eyepiece and to my dismay, mars shot through the viewing diameter in less than 10s.. Well it seemed around 5s. I had put mars on one edge and by 5s it had moved to the center and out of view.

I always thought that gotos would track an object, after I have put it into view. I do realise this is a planet so has more movement than the normal sidereal rotation of stars, but i had set my goto to target astronomical objects.

Is this expected behaviour or have I done somethig wrong in one of the settings?

Would appreciate all the help I can get. Btw I am unsure if this happwns in lower power since didnt check, however it could be more subtle in that power if it did and I will need to spend more time to see if it is happening

Thank you and happy mars viewing

mental4astro (Alexander) · #2 09-04-2014, 08:17 AM

You sure you followed the correct set-up proceedure for the mount? By what you are describing, there is NO tracking happening at all.

Draco (Draco) · #3 09-04-2014, 08:36 AM

Hi Alex

Actually I don't remember doing any set-up procedure for the mount. I had basically started using it as soon as I got it

So yea my bad.

Do you know how I can set it up?

Thank you

Merlin66 (Ken) · #4 09-04-2014, 08:50 AM

It should all be covered in the Instruction manual.....

jenchris (Jennifer) · #5 09-04-2014, 09:35 AM

I'm sure you missed something in the setup (especially if you didn't actually do one)
Once you have explored all possible problems, read the instruction manual.....
D'oh!

Draco (Draco) · #6 09-04-2014, 09:47 AM

Thanks JenChris. I guess its a simple case of http://en.wikipedia.org/wiki/RTFM

Draco (Draco) · #7 09-04-2014, 01:09 PM

Hi Guys

Checked the manual online and I am doing everything as expected. Will give it a go tonight again and if all fails, will take it to Bintel since it is still under warranty.

Thank you all

38degsouth (Dean) · #8 09-04-2014, 01:38 PM

Hi Niv -PM me if you'd like a basic setup run-through in simple point form. I run an older 8" LX90 for visual observing in alt/az configuration. Best of luck with getting your 'scope running and tracking.

Regards, Dean

AndrewJ · #9 09-04-2014, 02:46 PM

Gday Niv

Are you Polar or AltAz?
Have you done a drive train?
What Fimware version is loaded?
After fitting the 10mm, did you have to use the slew keys to recentre Mars?, and if so, what speed was the Hbx set at when you slewed?
If it is drive train related, the system may "appear" to stop tracking whilst the gears are reversing after you slew against the tracking direction.
ie it may take 10secs for the OTA to actually start moving again, depending upon how much slop is in your drive train.

Andrew

Draco (Draco) · #10 09-04-2014, 03:40 PM

Hi Andrew

Thank you for your response.
My scope is in Alt/Az (no wedge, just the standard mount)
havent done a drive train

I will boot the system up tonight and get the firmware version
yes, after putting the 10mm, i did have to use the slew keys. I think I used the digit 2 or was it 4. Dont know what speed that comes out as

Once I had changed eyepieces and used the audiostar to retarget mars, i used the slew keys to get mars in the center. however it just went through the field of view and out. I must have waited another 5 - 10 seconds to see if it came back into view but it didnt so I used the slew keys again to get it into view. All the time, while I wasnt doing anything, the motor in the mount was buzzing away, guess it was doing something but not the right thing?

If it makes any difference, I saw mars go from bottom left of the scope, diagonally to the top right. From memory, ACF/SCT have their left/right reversed so that would mean that mars was in actuality moving right bottom to left top, which would be what was actually happening. Does this mean that either my mount was not doing anything or wasnt fast enough to counter mar's movement or worse yet, it was going in the opposite direction to mars movement? (sorry too much caffeine.. cant think straight.. am uttering gibberish.. will end now)

thank you

Merlin66 (Ken) · #11 09-04-2014, 03:52 PM

Sounds like you need to set-up the "tracking" option....
Follow the procedure outlined on p17/18 of the Instruction manual to set up the Autostar controller.

Draco (Draco) · #12 09-04-2014, 03:56 PM

Hi Ken

Thank you for your response. I already tried instructions on those pages, but didnt help

Regards and thank you

Merlin66 (Ken) · #13 09-04-2014, 04:03 PM

Hmm
When looking at a distant object...is the mount tracking? i.e. the telescope actually moves...
RA lock?
Batteries Ok?

julianh72 (Julian) · #14 09-04-2014, 04:58 PM

Quote:

Originally Posted by Draco

Hi Guys

Checked the manual online and I am doing everything as expected. Will give it a go tonight again and if all fails, will take it to Bintel since it is still under warranty.

Thank you all

Draco,

I'm confused - did you, or did you not, start the evening's viewing with a "Two-Star Easy Align" as set out on pages 18-20 of the user manual http://www.meade.com/software-manual...=6:lx90-manual ? (Page numbers are for Meade manual ref. 14-6700-21 rev001 07/12 - see the last page of the manual to see if we're using the same document.)

In this post you say you are doing it all "as expected", but in an earlier post, you said you "don't remember doing any set-up procedure for the mount". (You would remember aligning the telescope if you had done it. If you never saw the "Alignment Successful" message on the handset, you have NOT aligned your mount.) Once you have gone through the initial alignment procedure a couple of times, it only takes 2 - 3 minutes to get your scope aligned each time you set it up.

If you skip the two-star alignment procedure, you can drive the mount as a dumb powered Alt-Az, but it won't track stars, or GoTo targets. (I guess the telescope controller "assumes" that it started the night in the "Home North" orientation, or some other default orientation, so will drive the motors accordingly, but the tracking speeds will be all out of whack if that was not the case.)

Once you have done the initial alignment, you can GoTo any target in its database (or manually enter the coordinates), or just manually drive the scope around using the handset controller buttons (DON'T release the clutches to manually slew the scope!), and it will track whatever you stop on once you release the drive control buttons.

AndrewJ · #15 09-04-2014, 07:03 PM

Gday Julian

Quote:

If you skip the two-star alignment procedure, you can drive the mount as a dumb powered Alt-Az, but it won't track stars, or GoTo targets.

Not quite true. If you start the scope as AltAz when it is pointing North and level, and enter the correct time, it will still "assume" that it was aligned ( but maybe not too well ) and start tracking as soon as you set its Targets to "Astronomical". It is better to do a one or two star align ( even if dummy ), as that will automatically start it tracking.
I suspect its more a drive train / rubber banding error.
Using a 10mm EP is like looking through a straw with a 10" scope, and any slight drift/rubberbanding will allow Mars to drift from the FOV.
An easier test is to use the 32mm EP and "goto" a starfield near Mars, then watch and see if it has a delay before tracking resumes when you use the slew keys. Speeds 2 and above on the Hbx can cause the motors to reverse and hence invoke backlash application, which can be woofy if the drive train nos dont match the real gear slop.

Andrew

Draco (Draco) · #16 11-04-2014, 09:57 AM

Hi Julian

When I saw Alexandar's reply, I presumed he was talking about something I needed to do once-off when I had bought the scope. However when I went through the manual online (which I always try to read when I get something new

) to double check, the "setup" was basically what I was doing before each observation anyways. That is why I said I was doing "everything as expected"

The scope was correctly aligned since when I did a GoTo to Mars, it put mars dead center in the field of view of the main scope

Sorry for the confusion and thank you for your reply

Quote:

Originally Posted by julianh72

Draco,

I'm confused - did you, or did you not, start the evening's viewing with a "Two-Star Easy Align" as set out on pages 18-20 of the user manual http://www.meade.com/software-manual...=6:lx90-manual ? (Page numbers are for Meade manual ref. 14-6700-21 rev001 07/12 - see the last page of the manual to see if we're using the same document.)

In this post you say you are doing it all "as expected", but in an earlier post, you said you "don't remember doing any set-up procedure for the mount". (You would remember aligning the telescope if you had done it. If you never saw the "Alignment Successful" message on the handset, you have NOT aligned your mount.) Once you have gone through the initial alignment procedure a couple of times, it only takes 2 - 3 minutes to get your scope aligned each time you set it up.

If you skip the two-star alignment procedure, you can drive the mount as a dumb powered Alt-Az, but it won't track stars, or GoTo targets. (I guess the telescope controller "assumes" that it started the night in the "Home North" orientation, or some other default orientation, so will drive the motors accordingly, but the tracking speeds will be all out of whack if that was not the case.)

Once you have done the initial alignment, you can GoTo any target in its database (or manually enter the coordinates), or just manually drive the scope around using the handset controller buttons (DON'T release the clutches to manually slew the scope!), and it will track whatever you stop on once you release the drive control buttons.

Draco (Draco) · #17 11-04-2014, 10:00 AM

Hi Merlin66

I can hear the gears running when it is pointing to an object. Cant remember if it was tracking when I had the 30mm eyepiece in but definitely not tracking when the 10mm eyepiece was used.

RA locks was done. Batteries are ok - I use a jumpstarter and it was fully charged.

Quote:

Originally Posted by Merlin66

Hmm
When looking at a distant object...is the mount tracking? i.e. the telescope actually moves...
RA lock?
Batteries Ok?

Draco (Draco) · #18 14-05-2014, 04:41 PM

Hi Guys

The telescope came back from Bintel. I was told that the firmware was updated and the drive trained.

However I am having the same issue. I did some more tests over the last few nights and came up with some more specific instances when the drift happens

After ensuring the tripod, telescope are level and telescope is pointing North, I Easy Aligned the telescope (using 2 stars, I am using Canopus and Spica).
Using the GOTO I was able to get to Mars (Mars seemed a bit off center so I used the arrows to get it to center and then pressed Enter 3 times to synchronize the new position). I then found that the LX90 tracked Mars for at least 1 hour! The same was for any object that I used the GOTO function to get to.

Now once I had done a GOTO to an object, if I used the arrow keys to even move the smallest of distance, the object started drifting! This was the same even if after alignment, I used the arrow keys to get to an object!

Is this normal? I want to learn star-hopping so that I have a deeper grasp of the night sky. I know a Newtonian is more made for this but having a GOTO as a backup when I cant find what I am looking for is nice.

Am I able to use the arrow keys to get to an object and have it tracked by the LX90 or is tracking only available when the GOTO function is used? BTW with a 10mm eyepiece, Mars went from one end of the field of view to the other and disappeared out in close to 15s.

Thank you

AndrewJ · #19 14-05-2014, 04:51 PM

Gday Niv

What firmware version is loaded??
What are you backlash settings set to?

In altaz, you can slew using the hand control after a goto to any object and it should keep tracking. The only time it ( normally) drifts after aligning is if the backlash isnt applied correctly/quickly enough on reversing.

Andrew

julianh72 (Julian) · #20 14-05-2014, 05:06 PM

Quote:

Originally Posted by AndrewJ

Gday Niv

What firmware version is loaded??
What are you backlash settings set to?

In altaz, you can slew using the hand control after a goto to any object and it should keep tracking. The only time it ( normally) drifts after aligning is if the backlash isnt applied correctly/quickly enough on reversing.

Andrew

As Andrew says:
How long did you wait before concluding that the tracking wasn't working after manually driving to a new target?

If I recall correctly, when we first set up my father's LX90, it would sit still (apparently) for about 15 seconds or so after manually driving it to a new target (depending on which directions you approach the new target from), and then the tracking would pick up again. At high power, the target would often drift out of view before the scope started tracking again.

I think we needed to re-set the backlash settings (Alt Percent and Az Percent - see page 28 of the user manual), and now it tracks pretty well instantaneously at all times, whether manually driven to a target, or using the GoTo functions.