Derek it's in the files section here in this group
Where
can I find that Beta ?? I am about to rebuild my G11 and would like to install
that..
Derek
?
?
If
you have the ability to plate solve, and to remotely power cycle, you can reset
the optimal CWD position (to within a few minutes in both RA/DEC) by the
following?process;
- I get the mount
roughly in the right place (I do this via CCTV, but eyeball would be fine
to?your?tape marks) and Cold/Warm Start it.
- Do? a slew to
somewhere just to the east of the meridian, near the celestial equator
- Do a?plate?solve?and
sync.
- Park back at?CWD.
- With tracking
stopped, slew manually in dec (note, from parked, a manual slew will start
tracking going again so you need to stop it again) ¨C at this point look at
the hour angle ¨C Ideally should be very close to +/- 6hrs.
- If it is not, work
out which way the mount needs to move when at?CWD?to
achieve this. (I find this the hardest step, and invariably get it wrong ¨C
try a small movement first!). Park at?CWD?and
do this movement manually using the hand control while watching the HA/RA
values.
- Immediately
Reboot/Power cycle and do a *Warm Start*
- Repeat the
process, by slewing to near the meridian. Hopefully, the HA should be
closer to +/-6. If not, you made the correction in the wrong direction.
- Repeat corrections
as needed to get closer to the right HA value ¨C I can usually get to
almost the right position in 1 or 2?iterations ¨C certainly close
enough to allow meridian flips to work (I flip at 12min past meridian ¨C
safety limit is 20min past).
The position will be slightly different if you
plate solve from the west in step 2/3 - I choose east because this is where a
flip starts.
Runaway slews: I know of 2 causes - a) On the
Gemini 2 firmware, there were issues with short corrective slews (eg for
centering after platesolve) - the beta (still??) from 2018 solved this. b)
broken cable/dry solder joint on the relevant port resulting in lack of encoded
feedback as Michael describes. I've experienced the latter with a remote G2 -
it's bad luck.?
?
?
I have
placed tape markers on the RA and DEC arms when I manually tightened the
clutches with the scope in the best CWD position. If I need to realign CWD I
can do this via manual slewing via remote camera to align my markers then
remote power off the mount and then power back on with cold start. This
*should* remove all modelling and restore the alt/az position for CWD.
I¡¯ll
cold start again and see if I can get the same behaviour to occur.
I¡¯m
thinking I might platesolve 6-8 stars around the sky to build a model, but in
imaging sequences ensure platesolves don¡¯t add additional syncs to the model to
rule out model getting warped.?
I¡¯m not
to concerned if it won¡¯t do things properly as I have a new premium mount
coming soon, but would prefer not to have collisions or bad accidents in the
interim. It¡¯s kind of a learning experience to see what can and can¡¯t be done
here for now..
?
Do
*not* plate solve at (or near) the
pole ¨C this can lead to all kinds of issues (a very small pointing error can be
many hours of RA out) and this can throw the pointing model out entirely.
?
Graeme
?
?
A Possible solution.. Maybe.. Plate
Solve at the pole, then select Park Here.. Cycle the power, and then cold start
and you be much closer to CWD / The startup position you seek.. Maybe Sharcap¡¯s
Polar Routine would be useful..
?
Synching to a known object and then
Parking at CWD should also work.. if not the above might..
?
I have read that remote operators
use video to monitor where their scopes are pointed / view the bubble level in
the saddle, etc so they don¡¯t have to physically return to ¡°fix things¡±..
?
I am always at my scope, so these
are just logical solutions, but might help..
?
Derek
?
?
Hi Daniel,
You are using a
Park feature that I've read about in the Gemini manual, but never
tried.??
That is the
ability to set your own Home park position that is separate from the CWD
position.??
Reading your
description, it seems possible the system got "set" so the Home
position was to the Western position you were last pointing to.? Then
after that, each time you tell it to go Home, it just goes to or stays at that
location.? However, if you tell it to go Park to CWD, it should go to CWD
as a universally known position.??
Anyway, if I've
misinterpreted your message, I apologize.? I would say though that
unattended operation of the Gemini system can be hazardous and should be
carefully monitored.??
One reason for the
caution is that there have been reports of runaway slews.? The causes have
not been resolved.? The Gemini detects only the motor rotation by getting
electrical pulses from the motor's optical encoder.? If those signals
don't get received, it seems that the Gemini can keep DC motor power going
without any "time out" protection.? This happened to another
owner recently, and that slew (when it was supposed to Park I think,) wrapped
his DEC cable and broke his gearbox.??
Best of luck
resolving your Park / Home issue,
?
On Wed, Jan 12,
2022, 7:47 PM Daniel Judge <dan@...>
wrote:
Was this one ever
resolved?
I'm experiencing the same issue after running the mount in a remote
installation. I'm becoming more confident in that the mount just isn't cutout
for this work. Bugs everywhere..
With the mount powered on for two days, it's suddently not able to park to CWD.
I have been powering on from CWD, Cold Start. I will plate solve and sync to
4-5 stars covering the West/East or the Meridian and then do my imaging run,
which does it's own plate solve and sync on repositioning and imaging run.
For two days it has finished the session, run HOME command, then PARK command.
And everytime it flews to CWD position and goes into Park mode.
Now just on the third night.. at the end of the session, HOME command just
stopped the mount in it's last position pointing at the Western horizon from
it's last image run, and parked in the same position. If I unpark, then from
the Gemini.net hand controller go to Park at CWD, it just parks itself in the
same position.
-- Brian?
Brian Valente portfolio
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