Meade LX10 RA Drive Speed

[RadarDave]

Hi, Fist post on forum.

I have been gifted a Meade LX10 from a widow of friend who sadly passed recently.

Getting on ok but I am unsure of how to make use of the drive mechanisms. I understand that the Dec has a limited use, but I can sort of get that given the mechanics of the system, The RA drive however is a bit confusing. Having done an accurate alignment on the pole star, with the wedge latitude set correctly etc, I then found a brightish star to the North, about 35 deg above my horizon. I then switched on the RA drive and was surprised to find the star moving fairly quickly out of the FOV. It appeared that the speed of drive was too fast. I checked the drive speed using a stopwatch and it appears to be correct at 15 deg per Hour.

Am I expecting too much from this system ? I thought the idea was to allow accurate star tracking for long exposure pics. If I  am wrong, how do I use the 2 axis controller when taking long exposure pics of stars and planets etc.

 I know this telescope is now more than 25 yrs old, but was hoping to get some good use of it for a few years yet !!

Any advice would be greatly appreciated.

Dave

South Scotland

[michael8554]

Could be Periodic Error.

Over a long period of time the speed will appear to be correct, but over a 4 minute period (the worm drive period) the speed will be, for example, fast for 2 minutes, then slow for 2 minutes, in a roughly wave pattern.

If it is PE the left to itself the star will drift out and back in to the eyepiece FOV over 4 mins.

Michael

[RadarDave]

Hi. Thanks for taking the time to reply.

I think my problem is rather more basic. The Meade LX10 with it's wedge mount etc, I believe constitutes an equatorial drive system, when aligned correctly on the North Pole.  There is no computation, with RA and Dec auto movement. Just a 24 hr RA clock driving system. I cannot see how this system could possibly keep a star in the FOV, (rotating around the pole star) with the RA compensating for the Earth's rotation in one axis direction.   Is it that this rather crude system would work for Planet observation (and to some extent for the moon) for observations / camera exposures, for perhaps a few minutes or so, but cannot track the stars, (without movement trails) to enable for very long exposures ie several minutes or tens of minutes ?

Is it not the case that more modern drive systems work both RA and Dec axis, in two directions, driven by computer software ?

Anyway, I obviously have a lot to learn in regard to using this telescope. It will be fun, I am sure !!

Regards

Dave 

 

 

Edited June 3, 2020 by RadarDave

[michael8554]

Hi Dave

The LX10 lacks the features to do DSO imaging.

I had a LX6 which had a very accurate RA drive system plus PEC plus guiding, but the crude Dec drive, same as yours, made imaging difficult.

With Good Polar Alignment a star should remain in the eyepiece in terms of vertical movement, but a basic RA drive with no Periodic Error Correction means the star will drift in RA as I described.

You could modify the HBx to allow guiding, but the crude Dec drive would be the limiting factor, as with my LX6.

A good Visual and Planetary imaging scope.

Michael

[Ceramus]

I've had an LX10 for 23 years now and it has given me many hours of great observing. But attempts at imaging have not been successful . The RA drive has quite a large periodic error and so trailing  star images on long exposures. Accurate and precise polar alignment also difficult as I suspect the fork mounting is not perfectly ortogonal in both axis.

Visually though it's a great scope and I'm sure will seve you well, especially as it has been gifted! 

[RadarDave]

Ok Thanks folks for the replies.

So, am I correct then, then that the LX10 RA mechanism is designed to allow time movement tracking of say a few minutes, on our solar system objects, but does not allow for long camera exposure times for stars (eg objects outside our solar system. ) ie stars, galaxies etc.

Regards

Dave

[michael8554]

Generalising here,  most mounts costing less than £8K won't track accurately enough to image with long focal lengths such as the LX10 for more than a few minutes, usually much less, without Guiding.

Michael

[RadarDave]

OK Thanks for that.  I really appreciate the help here.

I do understand that my LX10 does not have a sophisticated (expensive) motor drive system, but surely it has some use !

Maybe if I can ask a few, I hope simple, Yes / No questions. Assuming my RA drive is ok, ie 15 deg / Hr, and the wedge is correctly aligned to North Star etc at my latitude. 

1. Will my LX10 RA drive system help to give me long exposure (2 or 3 mins) pics/viewing of stars and galaxies, without trails.  Yes or No ?

2. Will my LX10 RA drive system help to give me long exposure (10 to 60 secs) pics/viewing of our Planets or the Moon.  Yes or No ?

3. If answer to both questions is No, what use is the LX10 drive system ?

OK I can use the control box to switch RA and Dec motors when viewing, but I can just as easily use the manual controls for this !

Sorry if I am being stupid with all this, so please be patient...…...

Regards

Dave

 

[michael8554]

1) and 2) I have no experience of this mount.

3) It's a fine Visual scope.

Touching the manual controls can make the view wobble, the Hbx can apply smooth corrections.

Michael

[RadarDave]

OK thanks anyway.

Maybe I need to get on a Meade forum.

Cheers from South Scotland

[Mark2022]

On 05/06/2020 at 16:47, RadarDave said:

OK thanks anyway.

Maybe I need to get on a Meade forum.

Cheers from South Scotland

Hi Dave, I'm South Scotland too and have just bought an LX10 used. It has the RA and Dec drives but, while the hand controller seems to operate, when the drive is switched on, my RA drive just doesn't move. No sound. Nothing. When I press 'W' on the HC, it will engage and move but pressing 'E' does nothing at all and, while my plastic DEC gears will turn when pressing 'N' and 'S', the DEC does not actually move. When the drive switch on the mount is switched on, there may be a very faint red light but it is only when I press 'W' that the light appears bright.

Have you had any luck with yours since posting this?  If so, did you get someone in the UK who either can fix or guide one toward fixing things? Like you, I feel like I have bought a complete dud since, while the OTA/Optics are fine, an entire mount drive (expected to work) appears useless. I didn't buy it to use manual slow motions, I bought to do as you wish too.

Cheers.

[Cornelius Varley]

@Mark2022 the OP (Radardave) hasn't visit the forum since 2020. I doubt you will get a reply.

[gordon-t]

On 23/10/2022 at 13:09, Mark2022 said:

Hi Dave, I'm South Scotland too and have just bought an LX10 used. It has the RA and Dec drives but, while the hand controller seems to operate, when the drive is switched on, my RA drive just doesn't move. No sound. Nothing. When I press 'W' on the HC, it will engage and move but pressing 'E' does nothing at all and, while my plastic DEC gears will turn when pressing 'N' and 'S', the DEC does not actually move. When the drive switch on the mount is switched on, there may be a very faint red light but it is only when I press 'W' that the light appears bright.

Have you had any luck with yours since posting this?  If so, did you get someone in the UK who either can fix or guide one toward fixing things? Like you, I feel like I have bought a complete dud since, while the OTA/Optics are fine, an entire mount drive (expected to work) appears useless. I didn't buy it to use manual slow motions, I bought to do as you wish too.

Cheers.

Take a look at the LX10 forum at https://groups.io/g/LX-10

You should find help there. Press E simply stops the motor.

New pcbs are available if required http://www.clearline-tech.com/repair-parts/lx10/lx10-main.html

Edited October 24, 2022 by gordon-t