Jump to content


Photo

LX90 tracking issues

  • Please log in to reply
19 replies to this topic

#1 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 20 January 2014 - 09:19 AM

Hello,

I was wondering if anyone has experienced an ongoing issue i've had with my LX90 12" ACF.

I complete my alignment, slew to an object which is not quite centered, it's especially annoying if i'm trying to use a camera as it's not in the field of view.
I adjust the view to center the object, but then the tracking stops and I lose sight completely, I know the tracking stops as the ticking noise is gone.
According to the manual it should just keep tracking, i've occasionally gotten it to track the new position by selecting GOTO and stopping the slew, or re-selecting the object.
It's very flaky though and often won't work at all.

I've spoken directly to Meade who said to reset and train drives etc, i've now done this three times to no affect. The last attempt I noticed it seemed to work correctly for the first few tries but then stopped. Meade said they'd get back to me but I haven't heard anything yet.


Has anyone else experienced this? I'm hoping there is a simple explanation for it that isn't in the manual.


Many thanks in advance for the replies.


Daniel

#2 Christopher Erickson

Christopher Erickson

    Vanguard

  • *****
  • Moderators
  • Posts: 2272
  • Joined: 08 May 2006
  • Loc: Waikoloa Village, Hawaii

Posted 20 January 2014 - 01:24 PM

Strange problem.

Are you using an Autostar 497 or an Audiostar?

Do you have access to another hand controller for testing purposes?

Do you have a spare handset cord?

What are you using for a power supply and how many amps of capacity does it have?

Are you in Alt/Az or RA/Dec orientation?


#3 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 20 January 2014 - 01:45 PM

I'm using the Audiostar, the issue has been apparent with both of the firmware versions i've used.
Unfortunately I don't have a spare hand controller, although I could probably get a spare cable.

I've used a 22AH Lithium Polymer and a 17AH Lead acid, both are quite new still.

This is in Alt/Az.

Was hoping someone would have replied with a "oh your doing this wrong".

Contacting the place I bought it from so hopefully they'll investigate

#4 Christopher Erickson

Christopher Erickson

    Vanguard

  • *****
  • Moderators
  • Posts: 2272
  • Joined: 08 May 2006
  • Loc: Waikoloa Village, Hawaii

Posted 20 January 2014 - 02:20 PM

I'm using the Audiostar, the issue has been apparent with both of the firmware versions i've used.
Unfortunately I don't have a spare hand controller, although I could probably get a spare cable.

I've used a 22AH Lithium Polymer and a 17AH Lead acid, both are quite new still.

This is in Alt/Az.

Was hoping someone would have replied with a "oh your doing this wrong".

Contacting the place I bought it from so hopefully they'll investigate


I have pinged the guru of all things Meade firmware-related (Andrew Johansen.) Hopefully he will have a moment to stop by and give his two cents.

#5 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 20 January 2014 - 03:35 PM

Gday Daniel

the issue has been apparent with both of the firmware versions i've used.



Which are????
Did you run patched firmware????
( so we can grab some extra data if reqd )

I havent heard of your specific problems in AltAz,
but a bit of deduction may get us further.

Andrew Johansen Melbourne Australia

#6 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 20 January 2014 - 06:16 PM

Sorry I didn't mean to be so vague intentionally, thank you for getting back to me so soon.

I am currently running A1F7 Audiostar firmware, which is the star patch version.

Previously I was running what came default with the mount, I do know the last time I used ASU to update automatically it forced 5CE2 onto my audiostar handset and I was stuck with it for a while until someone was able to help me.

On all version I had the tracking issue.

#7 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 20 January 2014 - 07:58 PM

Gday Dan

I am currently running A1F7 Audiostar firmware, which is the star patch version.



Starpatch hosts the std Meade firmwares, as well as our patches
so have you loaded raw A1F7 or patched A1F7????
That said, A1F7 when patched should work quite happily.
Unpatched, there are some bugs in the drive training process,
( where if your number is too high, Meade just truncate it back to a low default )
and these may manifest as "no tracking" as the scope works its way through the residual lash.
Soooo,
a) Is it patched
b) What drive train values does it have for RA and DEC
c) What backlash percentages do you currently have.

Andrew Johansen Melbourne Australia

#8 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 21 January 2014 - 05:04 AM

I'm running the patched version, I applied the patch to the standard Meade A1F7.
AZ/RA Train - 269 ALT/DEC Train - 169
AZ/RA Ratio - -2.75074482 ALT/DEC - +02.75074402
I wasn't sure where that info was kept so I looked through all the menus on the hand controller.

I've spoken to the place of purchase and it seems like they'll take a look for me so trying to get it to them today.
Appreciate the help though it's good to know it's not the firmware version before I take it to them.

#9 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 21 January 2014 - 06:03 AM

Gday Dan

I wasn't sure where that info was kept so I looked through all the menus on the hand controller.



I wanted the Alt and Az Backlash "percentages", not ratios.
Also, as you are patched, you can use my PEC Editor to read all this data ( plus lots more ) out into a single screen as well.

That said, when you reverse direction, the scope has the ability to apply a very rapid spin to remove the bulk of the backlash. The amount of lash done fast is given by the Train value by percentage.
Based on your Az Train being 269, ( that means 269 arcsec of slop )
if you have a percentage of zero, no lash will be applied at high speed.
Assuming the axis was tracking at sidereal ( ie 15arcsec/sec ), it would take about 18 clock seconds to start moving. If you were tracking much slower in Az, then the time to reverse goes up. The motor is still moving, but until the gears fully reverse, the OTA will stay stationary.
If you set the percentages to 100, on reversing, the scope will apply the 269 arcsec very fast ( and may give a kick in the EP ), but should start visibly tracking almost immediately.
Soooooo, what lash percentages do you have?

it's good to know it's not the firmware version



The patched A1F7 has been running for years now and i have never heard of what you are seeing.
I suspect that maybe the lash is not getting taken up quickly enough, but a few checks can confirm that.
ie the motor may really be running, but as its unloaded, you may not hear it.
There is a special bit in my PEC editor that can read out the raw motor encoder values, and that can 100% confirm whats going on.

Andrew Johansen Melbourne Australia

#10 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 21 January 2014 - 09:53 AM

Thank you Andrew.

I ended up taking it to the place if purchase. When I mentioned I had your patched firmware they said they were sure it wasn't that and think it may be the motor controller.
Either way I'll update this thread so that anyone experiencing this in the future will know what the issue was.

#11 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 23 January 2014 - 06:06 AM

So I just got news back that the issue has been resolved!

They replaced the Dec motor driver and it seemed to fix it. He also mentioned that the issue persisted with my particular version of Starpatch, some how I had version 1 in stead of the version 3. He still doesn't think it's to do with the firmware but mentioned it anyway.
It's all good now with v3 of the Starpatch and i'm looking forward to collecting it tomorrow so I can start getting some images of M82!

Thanks again for assisting me so quickly Andrew.


Daniel

#12 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 23 January 2014 - 04:39 PM

Gday Dan

some how I had version 1 in stead of the version 3



I assume they meant V1 and V3 of the patch for A1F7???
If so, as they noted, it still shouldnt have had any effect,
as i have never heard of your particular symptoms.
There was a bug re really bad tracking at certain positions
but this only applied to early model motor cards that came out
with the first GPS enabled units.
Again, this was rough tracking only, not tracking stopping.
Anyway, see how it goes.

Andrew Johansen Melbourne Australia

#13 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 27 January 2014 - 06:41 AM

Yeah I was using V1 instead of V3 for A1F7.
I've noticed with the V3 i'm getting a message on boot up mentioning that i'm on a trial version and it then proceeds to get me to enter the time and date.
I understand that Starpatch was made to allow you to add GPS capabilities to non GPS scopes but correct me if i'm wrong the patch is also useful for GPS enabled scopes for the fixes?
Do I still need to purchase a licence to use these patches? As currently I need to enter date and time manually despite having a GPS mount. Or has it been patched incorrectly?

I will be messing around with it tonight but wanted to see if I was misunderstanding something.

Edit: Sorry I should have mentioned that the service place installed the V3 version and I think they just used the default patch options which is why this happened.

Daniel

#14 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 27 January 2014 - 08:00 AM

Gday Dan

I understand that Starpatch was made to allow you to add GPS capabilities to non GPS scopes but correct me if i'm wrong the patch is also useful for GPS enabled scopes for the fixes?


Part of the patch is to allow the StarPatch GPS module to be integrated into the firmware, and the rest as noted is bug fixes and enhancements.
You really should apply the fixes if you want to remove the listed bugs.
We actually supply the patches in a different form ( ie without the StarGPS bits ) for use with Meades ASU, but StarPatch is so far superior to ASU, that we just tend to use the extended patches and deselect the StarGPS bits as required.

Do I still need to purchase a licence to use these patches?

Nope, the patches and loader are freeware.
Starpatch works fully as a loader without registration, but throttles back the speed for half the load. Other than that, it is fully functional.
Normally, if you did not have a registered version, you would simply load the patch but not select the first few options ( ie those related to the StarGPS module ).
If you just reload V3 without the StarGPS options selected, it will remove the "trial" notice functionality, and your GPS should work again.
( I didnt know the Meade GPS got bypassed, as the patch is supposed to default to normal operation if an external GPS isnt found, so im a bit confused there )

Andrew Johansen Melbourne Australia

#15 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 27 January 2014 - 08:08 AM

That makes perfect sense to me, thanks Andrew.
I'll reload without the GPS option selected tonight

Do you have any tips for me other than Training the drives and Calibration to improve GOTO accuracy?
The GOTOs were always on target before, at least in view of the eyepiece but now they are off by quite a bit. I was very careful with my alignment, which I tried three times.
I really want to get M82 on my cam but had a frustrating 3 hours last night with no luck.

Daniel

#16 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 27 January 2014 - 03:54 PM

Gday Dan

Good drive training is required, but LNT calibration has no effect on goto accuracy. ( LNT "calibration" only affects how well the scope finds the first align star. After that, it is no longer used, everything is based on the chosen stars and how well you centre them )
Auto align doesnt always give the best star pairs, so i always prefer to do a manual 2 star for best effects.
ie in AltAz, i try to get 2 stars that are pretty close to elevation 45deg and about 90deg apart in Az.

Andrew Johansen Melbourne Australia

#17 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 01 February 2014 - 06:56 PM

Hi Andrew,

I re-patched my firmware with A1F7 patch v3 today and got a good drive train procedure going then started my align. Straight away I noticed it was not tracking again.
I used Starpatch to apply a standard A1F7 and the tracking is fine.
Please understand I'm not blaming the firmware but I'm wondering if it is a symptom of another issue with my LX90?

A possible clue is now that I recall it the guy at the shop said I was using v1 of the patch but I remember now, by default Starpatch has V3 as default, am I correct in thinking this is true, if so I'm almost certain I had V3 before as well.

#18 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 01 February 2014 - 07:32 PM

Gday Dan

I am severely confused then :confused:
V3 has been out for 1 year, but had nothing new added that by default would possibly cause this.
The base patch ( V2 ) has been out for 3 years and this is the first report of this effect.
Can you tell me what patch options were chosen ( if different to default ) as that may narrow it down a bit.

Andrew Johansen Melbourne Australia

#19 dan_uk

dan_uk

    Sputnik

  • -----
  • Posts: 26
  • Joined: 15 Apr 2013

Posted 02 February 2014 - 04:17 AM

I turned off the first 3 options that aren't bug fixes. I left bug fixes as default and enhancements as default.

#20 OzAndrewJ

OzAndrewJ

    Apollo

  • *****
  • Posts: 1031
  • Joined: 30 Nov 2010

Posted 03 February 2014 - 07:49 PM

Gday Dan

Then i am currently at a loss to understand.
The only process now would be to remove options one by one till the culprit ( in your case ) rears its head. That may track it down, but it means lots of reloads, and thats just a pain unless you have a full version of the StarPatch loader.
Just for info, what RA/DEC train values do you now get??

Andrew Johansen Melbourne Australia






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics