Meade LX high precision centering...

[tooth_dr]

Can anyone advise?

I do a two star alignment and then slew to a target.  The object always goes outside the field of view of the camera, below and left, after it’s finished the high precision centering.   Can it be ‘recalibrated’?
 

[tooth_dr]

Meade LX600 14”

[Davey-T]

Don't know if it can be recalibrated but my 10" has always been pretty useless at centering stuff even after spending ages using it's pointing accuracy routine and drive training stuff, it's also got Smart Drive which I switched off as more trouble than it was worth, spent  lot of time taking it to pieces and rebuilding and getting rid of all the backlash which didn't help, errors also seem to be different depending where it's pointing.

Not sure if it's mechanical or software related so just live with it now.

Generally switch on and sync on a bright star beginning with A then GoTo target or near by bright star and use finder scope to centre it as once synced on something nearby it is quite accurate if it only moves a few degrees and plate solve for invisible stuff.

Dave

[tooth_dr]

54 minutes ago, Davey-T said:

Don't know if it can be recalibrated but my 10" has always been pretty useless at centering stuff even after spending ages using it's pointing accuracy routine and drive training stuff, it's also got Smart Drive which I switched off as more trouble than it was worth, spent  lot of time taking it to pieces and rebuilding and getting rid of all the backlash which didn't help, errors also seem to be different depending where it's pointing.

Not sure if it's mechanical or software related so just live with it now.

Generally switch on and sync on a bright star beginning with A then GoTo target or near by bright star and use finder scope to centre it as once synced on something nearby it is quite accurate if it only moves a few degrees and plate solve for invisible stuff.

Dave

I don’t know is my scope is different, but it slews to a nearby bright star, platesolves then moves to the target. It just seems to be off by the same amount in the same direction each time 

[Davey-T]

47 minutes ago, tooth_dr said:

I don’t know is my scope is different, but it slews to a nearby bright star, platesolves then moves to the target. It just seems to be off by the same amount in the same direction each time 

Sounds like a time or location issue so could be a software problem, there was a useful Meade Yahoo Group but not sure if it's still going.

Dave

[tooth_dr]

1 hour ago, Davey-T said:

Sounds like a time or location issue so could be a software problem, there was a useful Meade Yahoo Group but not sure if it's still going.

Dave

Thanks Dave. It’s GPS controlled unless that’s wrong.  I wonder is the initial tel alignment critical. It was done with EP then camera added  

[Davey-T]

GPS should be right, check there's no offset set, should be zero.

If I'm imaging I use the camera for alignment with crosshairs on screen.

Dave

[michael8554]

Like others who've posted, I GoTo, Centre, and SYNCH on a star near the target, then the GoTo the target is in the middle of my DSLR FOV  (LX200GPS 1280mm FL)

That's what Meade High Precision does automatically.

How far off is your first Alignment Star ? Should be visible, not necessarily central,  in the finder.

 

21 hours ago, Davey-T said:

it's also got Smart Drive which I switched off as more trouble than it was worth,

That's Meade-Talk for Permanent PE Correction, you need that to help guiding, as the uncorrected RA PE is usually rather large.

But switch off the Dec PPEC !

 

 

[tooth_dr]

1 hour ago, michael8554 said:

Like others who've posted, I GoTo, Centre, and SYNCH on a star near the target, then the GoTo the target is in the middle of my DSLR FOV  (LX200GPS 1280mm FL)

That's what Meade High Precision does automatically.

How far off is your first Alignment Star ? Should be visible, not necessarily central,  in the finder.

Thanks Michael. Yes it’s within the finder.  How do you sync on an object?

If I say chose m51, and goto it, and it ends up just off centre. Can I manually move it to the centre of the camera FOV. Then is there a way to resync the mount position so that future gotos work?  

[paul mc c]

5 minutes ago, tooth_dr said:

Thanks Michael. Yes it’s within the finder.  How do you sync on an object?

If I say chose m51, and goto it, and it ends up just off centre. Can I manually move it to the centre of the camera FOV. Then is there a way to resync the mount position so that future gotos work?  

Hi Adam,i used to own an LX200,and it memory serves me right when the scope slewed and the object wasn't in the center of the field i would center it with the hand set and press enter a couple of times and that sorted it.

[michael8554]

To SYNC, you hold the ENTER key down for 2 to 3 seconds.

The display says "Syncing" for a couple of secs IIRC, and then it beeps to confirm.

Page 30 of the Manual, in the sidebar.

If your finder is well-aligned with your imaging camera, centre the star on the finder, then the camera, then SYNC.

Same for target if not quite framed to your liking.

Michael

 

[tooth_dr]

On 01/04/2021 at 09:05, michael8554 said:

To SYNC, you hold the ENTER key down for 2 to 3 seconds.

The display says "Syncing" for a couple of secs IIRC, and then it beeps to confirm.

Page 30 of the Manual, in the sidebar.

If your finder is well-aligned with your imaging camera, centre the star on the finder, then the camera, then SYNC.

Same for target if not quite framed to your liking.

Michael

 

Cheers Michael, appreciate the help.