From: albe albo <richter1956@yahoo.com>
Date: October 6, 2008 7:52:36 AM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Re: Custom drive ratios disrupt tracking?
For my personal experience the version 4 (i tried up to alpha 4) didn't really change the situation.
Maybe (maybe) the mount reaction is less strong than the earlier versions but the guide on my mount is still overcorrected.
I explain better: eveluating the results in the long period (after 2-3 hours or so) we can say that the guide globally works fine and the star is still centered.
Evaluating those 2 hours with more detail we see that the mount quickly and continuosly bounces (approx 1 time for second depending on the exposure time) in a range approx of 6-8 arcsec allowing only photo with extreme short focal length.
Leaving the mount unguided allow me to do exposures up to 1 minute (better 45 seconds or less of course) even if some of those shots (35% approx) will be discarded because the PE is faster in some positions rather than in other positions so the stars are trailed.
I will keep the group informed about Shoestring + 909 (clone) because i 'm really really curious about this matter and i'dlove to enter the club of autoguider!
Unfortunately autoguiding = more weight, cable cluttering and more complexity in the setup while the unguided exposures are easy and simple to set in few minutes.
It's not possible to have all the thinghs at the same time of course!!
I posted a couple of images done from my terrace with the classical 45 sec. of unguided exposure (or 20 sec binned 2x2) with The Imaging Source camera.
TTYL (Talk to you later)
Alberto
080901-NGC6960-mosaic-test.jpg
080908-NGC6992-mosaic-test.jpg
If you are interested in further unguided images you may check there:
http://88.54.176.169/TIS-DMK/TEST-CHROMA/
Cheers
From: KirkusMcGurkus <kirk@stenvall.net>
To: Astro_IIDC@yahoogroups.com
Sent: Monday, October 6, 2008 12:24:45 AM
Subject: [Astro_IIDC] Re: Custom drive ratios disrupt tracking?
Alberto,
Thank you for this post. It's comforting to know that I'm not the only
one who seems to have this particular problem. I'll be curious to know
how your 909 box works. After a short storm front moved through, I'll
be able to set up tonight and test a few things. As soon as I receive
my new unlock key, I'll throw version 4 of AstroIIDC into the mix and
see if that corrects the problem. I'll post my findings here.
Thanks again!
Kirk
--- In Astro_IIDC@yahoogro ups.com, albe albo <richter1956@ ...> wrote:
>
> Hello Kirk,
> i guess i had problems similar to yours.
> Milton an me had a very long and intense brainstorming about my
LXD75 (autostar 497) testing some changes in the serial port command
sequence but until now i'm not been able to guide with my LXD75 (belt
transmission) .
> The calibrations always seems to succeed but the response of the
guiding seems exaggerate both in number of corrections than in
amount of corrections, while, leaving the star unguided, it is stiff
into the center slowly moved only by the PE (approx +10 -10 arcsec on
10 minutes for my mount).
> Milton suppose that almost surely it is a problem of my particular
LXD75 configuration.
> Now i ordered a 909 box and i will try using the shoestring
interface instead of the serial interface.
> Who knows maybe i will solve.
> Alberto
>
>
>
>
> ----- Original Message ----
> From: KirkusMcGurkus <kirk@...>
> To: Astro_IIDC@yahoogro ups.com
> Sent: Sunday, October 5, 2008 12:35:08 AM
> Subject: [Astro_IIDC] Re: Custom drive ratios disrupt tracking?
>
>
> Milton,
>
> Thanks again for all your help.
>
> I've just ordered an upgrade to version 4. Along with that, several
> minor adjustments I made to my mount, and drift aligning (I've avoided
> doing that, I suppose because I'm lazy), hopefully I'll be able to get
> more than 30 second exposures. :)
>
> It may just be that my lower-end LXD75 simply isn't capable of doing
more.
>
> Anyway, thanks again for your support.
>
> Kirk
>
> --- In Astro_IIDC@yahoogro ups.com, "Milton Aupperle" <milton@> wrote:
> >
> > Hi KirkusMcGurkus;
> >
> > I would seriously doubt that has any influence at all.
> >
> > During the Calibration process, we measure how much and what direction
> > it moves for the 4 axis. We make no assumptions like "RA +ve should
> > moves an onscreen star to the right", and actually measure it.
> >
> > The reason we make no assumptions is because we don't know how the
> > Camera is oriented, don't know if you've enabled one of those
> > controller switches that reverse movement directions (E is W , S is
> > N), don't know if your using a prism or flip mirror, don't know if
> > your using a Off Axis Guider, and you might be using "Flip Horizontal"
> > or "Flip Vertical" in Astro IIDC too. All of the above things can
> > cause all sorts of reversals of left / right / up / down, so we
> > measure rather than guess.
> >
> > Hope That Helps..
> >
> > Milton Aupperle
> >
> > --- In Astro_IIDC@yahoogro ups.com, "KirkusMcGurkus" <kirk@> wrote:
> > >
> > > Milton,
> > >
> > > Here's a quick question for you. Because I went from gears to belt,
> > > the actual direction of the gear ratios in my Autostar have been
> > > reversed. "+'s" are now "-'s" and vice versa. I'll bet this is
what's
> > > going on.
> > >
> > > AstroIIDC is giving the mount commands to move, but because I'm
using
> > > belts instead of gears, the motors turn in the opposite
direction then
> > > what they used to. AstroIIDC is saying move the motor in direction A
> > > but because of the belts as opposed to gears, direction A moves the
> > > mount in the opposite direction.
> > >
> > > Doesn't that sound about right?
> > >
> > >
> >
>
