Vixen SXD Question

[issdaol (Phil)]

Here is a question to all those Vixen SXD mount owners out there :-)

I was reading up on the SXD mount just recently and from reading the manual it appears that you do not actually have to polar align the mount.

Apparently you just setup do a very rough physical alignment then use the starbook and do a 2 star alignment and then it will track and goto.

Is this correct or did I read it all wrong?? Plus I am asuming that if it is correct it is only suitable for visual use and for AP you will still need to do a full polar alignment??

Thanks in Advance :-)

[RobF (Rob)]

Hi Phil,

It may then be aligned to point ok with mathematical corrections for position and how level, but it won't be polar aligned for astrophotography - you'll get field rotation if you try for long exposures unless you're well aligned sufficient for your focal length. If that's what you were asking?

[issdaol (Phil)]

Hi Rob,

Yes partially :-)

I had already assumed that if it was not properly polar aligned that you would not be able to do reliable long exposure astrophotography.

What I was trying to confirm is:

1. Will the mount track well enough for visual use without polar alignment and just using the 2 star alignment?

2. Will goto/pointing work too ??

Cheers

[Profiler (Profiler)]

Originally Posted by issdaol

Hi Rob,

Yes partially :-)

I had already assumed that if it was not properly polar aligned that you would not be able to do reliable long exposure astrophotography.

What I was trying to confirm is:

1. Will the mount track well enough for visual use without polar alignment and just using the 2 star alignment?

2. Will goto/pointing work too ??

Cheers

1A - Yes - Although I have found that it tracks best after 4-6 alignment points (you don't have to use stars). It sounds like a lot but inputting new alignment points IMO becomes quite easy with some practice.

2A - Yes

[JohnH]

Hi,

Yup it will track in both RA and DEC if the polar alignment is off and you have done 3 or more align stars. I am talking from memory here so I am not 100% sure (sold my Sphinx a while ago) but I seem to recall you cannot turn this feature off so, for AP work, it is best not to do more than a 2 star alignment as you do not want the mount moving in DEC and possibly fighting against your guiding. I think this will apply to any Vixen mount driven by the starbook - not just the SXW/SXDs. BTW I found the DEC backlash to be so large as to make AP very difficult (mind you I had a VC200L on it) but that is another story....

[LewisM]

If you are considering an SXW or SXD mount, you REALLY need the Nex boards - eliminates the dec backlash issue, and reduces noises.

http://www.nexsxd.com/NexSXD/NexSXD_eng.htm

I am still contemplating an SXW, just need to know it will run OK, since Dec backlash is a serious problem with the Starbook.

[issdaol (Phil)]

Hi All,

Thanks for the information.

Lewis the Nex board looks interesting but it seems they are not compatible with the Starbook.

Is the Starbook the cause of the backlash problem or the controller board which the Nex board replaces??

cheers

[LewisM]

Starbook is at fault. Vixen could never fix it, so they replaced it with Starbook TEN,which is NOT compatible with Starbook mounts at all.

If it is an SXD and you want to do astrophotography, you need to replace the board and hand controller.

Best bet is wait for an SXD2 or SXP. I have been offered a near mint SXW, at a VERY nice price, but it will take an additional $500 to get it decent for astrophotgraphy (when they work, they are BRILLIANT).

To be honest, photographically the SX range only holds 2 kg more than the VERY tried and VERY respected GPD2 - a true legend. Many a good astrophotographer use them for their travel mounts with smaller scopes. The GPD2 handles my 2 refractors VERY easily and accurately. I use the Synscan GOTO kit on it, and found it superbly accurate (though needed a recent tune up)