Starbook S Controller goto system Polar Aligining

[ashcb1]

I have a Vixen Starbook S controller I purchased some time back and I don't seem to be able to polar align my scope. I was wondering if there is anyone else using such a system that I might be able to contact for advice. Thank You

[marki]

I use the starbook in conjunction with an ascom driver and alignmaster which gets it pretty close. Not sure if thats any help?

http://enzerink.net/peter/blog/2008/06/28/ascom-star-book-driver

http://www.alignmaster.de/en_download.html

Mark

[selste]

Hi Mark,

using one on a Vixen GPD2 mount - what kind of problem are You facing?
Usually i simply align the mount with the built-in Polar Axis Scope and afterwards initialize the Goto system - generally with pretty good slewing results even at high speed.
Regards,

Steffen

[ashcb1]

The problem that I have is I can't see the scp from my location. One of my friends has a similar setup and is having the same problem as me.

My date/times/lats are correct and double checked. After a one or two pair alignement some times the scope gets close to the object that I am seeking and other times its way out.

[marki]

Hence why alignmaster and similar programs are really useful, you do not need to be able to see the pole to get close. Are you visual or trying your hand at AP? Which mount is it?

Mark

[selste]

Hi Mark,
the way i read your last comment You don't have an issue with Polar Alignment but with the GoTo setup.
After finishing the Polar Alignment procedure You should initialize the GoTo system with at least 3 stars for acceptable accuracy.
I think choosing the right reference stars is also quite important - east and west of the meridian as well as south and north of the (celestial) equator otherwise accuracy will noticably decrease depending on the area of sky You wish to observe!
Regards,

Steffen

[ashcb1]

I setup my scope with an iphone app setting the mount to true south and also have used a compass with a setting of 168deg. My scope is pointing East as per instructions. I use an Ipad app called SkySafari I connect via wireless to starbook and try aligning to a star pair. Sometimes after the alignment I get close to the object that I want and other times it is way out.

I really won't to get into AP but cant until I get this problem sorted. I don't know if its my setup or the me.

[marki]

You need more then two points. Try using 4 or 5 from all over the sky and it wll drop the target in the EP everytime. Which mount is it?

Mark

[ashcb1]

Yes sometimes I do try more than a one pair alignment where possible. When the weather improves again I will keep trying. If I can't get it right soon may ditch the starbook for something else that will work with my GPD2 mount and Vixen scope.

[marki]

Something must be wrong some where as the starbook is really one of the best you will get for visual use, a bit of a pain for AP but great for visual. I have two vixen mounts (SXW and SXD) that run the starbook and it works great on those. I know this is basic stuff but check for slop in your drive train and adjust it out. Also check that the clutch's are not slipping due to grease etc. Once you have the mechanical side the best you can get it set the backlash on the starbook so it responds immeadiately to direction input when the speed is set to the second lowest possible speed. Once that has been done use a GPS to get exact time and position and put these values in the starbook. Polar align the best you can using what ever method is easiest. From there it should be a no brainer, align on several points all over the sky and it should drop the object close to the centre of the EP every time.


Mark

[selste]

Hi,

although the Starbook S has a few quirks once You get the hang of it it works really well with the GPD2 ...
Slewing is very fast and precise and the noise levels are 'neighbourhood-friendly'.
Could You tell us how You normally try to do the Polar Alignment, step by step - maybe this would help to nail down the problem?
Regards,

Steffen

[ashcb1]

Hello Steffen,

here is how I set things up.

check level of scope and ensure that the north facing leg is pointing true south by using a Iphone app and checked with a compass and the scope is pointing East checked with Iphone app and compass

Check correct lat on mount

turn on starbook controller check time and date also lat and longs are correct if not adjusted

I use an Ipad to connect via wi-fi and I also check setting are correct and connect to starbook. On the Ipad I use skysafari. I then got to my first alignment star at present I am using Arcturus, Spica, Antares, Rigil Kentaurus or Hadar. I use the alignent key in Skysafari not starbook. Sometimes then when I want to go somewhere its close, spot on or way out.

I have checked the starbook map and the Ipad map as I thought it might be the Ipad app but both agree. Before using my Ipad to control my scope I still couldn't align.

Thank You for all your assistance

[marki]

Assuming all is right mechanically, have you adjusted for magnetic declination? From the coordinates you have listed on your profile the magnetic declination at your site is 10 deg 22" east. If you are aligning your scope using compass then thats how far you will be off which is a fair bit. Try aligning by finding magnetic south then shift the azmith to point the scope 10 deg 22" west of that line and you will be much closer to the pole. Also drop all the "i" bits and pieces and just use the starbook on its own to see if it works. All alignment points must be entered on the starbook as that is how the pointing model is built.

Mark

[selste]

Thanks for the detailed setup description.
Well, i second Mark - get rid of all the 'i' bits until You're proficient enough with the mount and the Starbook.
I know that the user interface can't compete with iOS ;-) but it's not that bad and once You're accustomed to it it's quite fun to use and really fast.

Right, after You've turned on the Starbook make sure the counterweight is in the lowermost position - R.A. axis pointing south.
Point the telescope EAST (because this is what the Starbook display will show when powered up), select a bright star (You can navigate + zoom in/out the display to select one) and let the scope slew to the position.
There will obviously be a positional error because the scope is not perfectly aligned therefore You need to make manual adjustments.
Repeat at least two times and be careful with the selection of the stars - east and west of the meridian and south and north of the equator for maximum precision.
The third star should already be placed almost dead center in the eyepiece with only minimal corrections necessary.
Afterwards You should be able to use GoTo without any problems - try it with a few selected targets.

Right, and NOW would be the time to attach all those 'i' gizmos to the scope.
Point the scope (via Starbook!!!) to a bright star, sync it to the app You're running and that's it ...
Cheers,

Steffen