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INDI Library v1.9.6 Released (Yesterday)

Bi-monthly INDI Library released with new drivers and bug fixes.

RST-135 mount - what are the best practices?

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I sometimes encounter problems where the mount travels the opposite direction of where it's been asked to go. For this reason, I home the mount every single time I boot it up. I've also seen where I might start it up, home it, and let it sit for a few hours, then issue a GOTO command and it doesn't know where it's pointing. So I have to home again, then reissue the command. I have no idea what causes this erratic behavior. I've also seen on occasion that if the mount moves from west to east, and you send it back west again, sometimes it thinks the shortest route is to continue east until it gets back to the point you sent it to. This makes the cables wrap around the mount. I also don't know why it does this.

But typically homing before using the mount in anyway keeps all these scenarios from happening.
-Andrew
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Mac Observatory - All about using the Mac for Astrophotography: www.macobservatory.com
Astrobin: www.astrobin.com/users/Lead_Weight/
The following user(s) said Thank You: Greg Stark
1 year 1 month ago #70272

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Yes, I think it's a good idea to have the HC handy in case the mount gets confused.
I intend to use this mount mostly for travelling to dark sites - I will need it anyway to update the location.
Max S.

RPI 4 B (4Gb) with SMate
Askar FRA400, TPO RC6, Nikon D5500 full spectrum (with IDAS clip-in filter).
ASI2600MC Pro
ZWO ASI120MM Mini on ZWO 30F4
ZWO ASI224MC-S on Orion 50 mm f/3.2
ZWO EAF x 2
SW AZ-GTi
SW HEQ5
RST-135
1 year 4 weeks ago #70350

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I found that leaving the mound in the "standard" parking position - scope pointing at NCP is pretty safe in terms of the backdrive.
So, in the end of a session I don't bother anymore driving it to RST's default home position (horizontal facing West).
Just reporting.

Waiting for the good weather to return and the Moon to go away to play more.
Max S.

RPI 4 B (4Gb) with SMate
Askar FRA400, TPO RC6, Nikon D5500 full spectrum (with IDAS clip-in filter).
ASI2600MC Pro
ZWO ASI120MM Mini on ZWO 30F4
ZWO ASI224MC-S on Orion 50 mm f/3.2
ZWO EAF x 2
SW AZ-GTi
SW HEQ5
RST-135
The following user(s) said Thank You: Stephen Wong, Greg Stark
Last edit: 1 year 3 weeks ago by maxthebuilder.
1 year 3 weeks ago #70565

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Update...

-- good people here on INDI forum recently fixed the driver (thanks!). Location push is now behaves as it should. It's only available on beta channel at the moment.
-- I went out to a remote dark location with RST-135 and RC6.
-- had the hand controller connected and GPS signal acquired.
-- launched KStars/Ekos (KStars was set to Mount updates KStars). Location got updated nicely.
-- all was good but I didn't realize that I had to change my parking position (pointing to NCP) - it was still using my usual location/longitude.
This caused some issues since it was parking in a crooked way. Once I copied/pasted the new longitude to the parking position everything became OK.

-- new thing I didn't know before - if you click Home Mount in INDI control panel RST-135/Main Control this will home the mount as the hand controller would (horizontal facing West)
Max S.

RPI 4 B (4Gb) with SMate
Askar FRA400, TPO RC6, Nikon D5500 full spectrum (with IDAS clip-in filter).
ASI2600MC Pro
ZWO ASI120MM Mini on ZWO 30F4
ZWO ASI224MC-S on Orion 50 mm f/3.2
ZWO EAF x 2
SW AZ-GTi
SW HEQ5
RST-135
The following user(s) said Thank You: Jasem Mutlaq, Greg Stark
11 months 6 days ago #72329

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I was thrilled to find this.  I did read the thread (tome?) on CloudyNights, but it doesn't seem like many there are on the INDI platform (I'm running StellarMate 1.6.1 on a Pi 4 with 8 GB).  Plus, I've forgotten much of what I've read since it's long, I'm getting old, and the thread is kind of all over the place.

I'm trying to set up a Borg 90FL with Starizona Apex feeding a QHY268C on an RST-135 (f/3.6, 325 mm when all is said and done).  I'm seeing the spikes you mentioned and look forward to trying the counterweight (my system is pretty light).  Also, my RMS numbers are horrid (~6 or worse), and I'm guessing that is a mix of operator error (I'm new to guiding... didn't really need it much in the past at this short focal length) and not enough light reaching the sensor of my ASI290MM Mini (I'm using an OAG, and the mirror is quite small—the guider keeps losing the stars and starting over).

I also have a 30mm f/4 guide scope, and I'll give that a try with your guide numbers tonight, skies willing.  What I was wondering is whether you have updated numbers?  I figured I might as well start with the latest-and-greatest.

Finally, I'm also seeing the unpredictable mount behavior mentioned above.  On a couple of occasions, it's lead to cord wrap—one time bending the USB socket of the mount (I'm learning this is a weak spot on the Rainbow Astro design but am learning to work around that).  I reached out to both the vendor and manufacturer, but neither have been responsive—a little disappointing and scary when you're trying to work through issues on a $4000 USD mount.  Anyway, I digress, but it does both me that the support has been lacking.

Here's hoping that you're still monitoring this thread!

Thanks,
Greg
The following user(s) said Thank You: Jasem Mutlaq
5 months 2 weeks ago #78318

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I think most of these problems have been eliminated through firmware and driver updates. You’ll learn to religiously home the mount after boot, or connection to software so that the mount knows it’s starting point. After that it will goto pretty good. A single plate solve using the align/sync will get you centered on an object. Really most default settings, even for guiding will be pretty straight forward. You will want to use .5 second guide exposures so the mount can correct quickly for the large periodic error that it has. Anything slower than .5 seconds and it can’t correct fast enough to keep up with the error rate, and you’ll drift off target and back again over a full cycle of the strain wave gear.

PHD2 can also be used with KStars/EKOS, and a full run of the strain wave gear using guiding assistant (4 minutes 20 seconds) will give you good settings to use for the mount. Ignore any backlash recommendation. Then the only other thing worth looking into is just how good you can get polar alignment.

Last, make sure you have the latest firmware.
-Andrew
––––––––––
Mac Observatory - All about using the Mac for Astrophotography: www.macobservatory.com
Astrobin: www.astrobin.com/users/Lead_Weight/
5 months 2 weeks ago #78343

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Greg,
I used the mount quite a few times since my last post.
Here's my latest practices.
-- I don't use the hand control. At all. Except for the initial setup months ago.
-- I have KStars set to "KStars updates all devices" for Time and Location.
(If I image at a remote location - I create a custom location in KStars beforehand)
-- After Starting KStars/Ekos it is important to "Home Mount" from INDI control panel
-- "simulate the pier side" should be OFF.
-- then I unpark/park to a preset position - scope pointing to NCP and do the rest from there.

Guiding.
-- I still do have those occasional spikes in RA (and DEC too)
They might have to do with seeing/light pollution since I just returned from a dark site where I didn't have those spikes.

My latest settings for guiding:
GPG off.
Guiding rate 0.5s (this is important - it should not be higher than 1s)
0.60 0.45
0 0
0.05 0.05
20 20

That's about it.
HTH and do not hesitate to as questions.
Max S.

RPI 4 B (4Gb) with SMate
Askar FRA400, TPO RC6, Nikon D5500 full spectrum (with IDAS clip-in filter).
ASI2600MC Pro
ZWO ASI120MM Mini on ZWO 30F4
ZWO ASI224MC-S on Orion 50 mm f/3.2
ZWO EAF x 2
SW AZ-GTi
SW HEQ5
RST-135
5 months 2 weeks ago #78344

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Yes, I know that a new and much improved driver was released but I hadn't tried it yet - I didn't want to break anything before going to a dark site.
Will try soon.
Max S.

RPI 4 B (4Gb) with SMate
Askar FRA400, TPO RC6, Nikon D5500 full spectrum (with IDAS clip-in filter).
ASI2600MC Pro
ZWO ASI120MM Mini on ZWO 30F4
ZWO ASI224MC-S on Orion 50 mm f/3.2
ZWO EAF x 2
SW AZ-GTi
SW HEQ5
RST-135
5 months 2 weeks ago #78345

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Andrew -
Does the new firmware make a difference? I was hesitant to install it and didn't.
Thanks!
Max S.

RPI 4 B (4Gb) with SMate
Askar FRA400, TPO RC6, Nikon D5500 full spectrum (with IDAS clip-in filter).
ASI2600MC Pro
ZWO ASI120MM Mini on ZWO 30F4
ZWO ASI224MC-S on Orion 50 mm f/3.2
ZWO EAF x 2
SW AZ-GTi
SW HEQ5
RST-135
5 months 2 weeks ago #78346

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A lot of firmware fixes have been bug fixes. For the 135E there was a fix for DEC excursions that were happening randomly when guiding. But the firmware has been better with every update. There has been work done on a new driver for INDI, which allows you to make a simple sky model with 7 point alignment. That could improve tracking as most imagers only solve a single point. And prior to this new driver, it only allowed one sync point to be stored.
-Andrew
––––––––––
Mac Observatory - All about using the Mac for Astrophotography: www.macobservatory.com
Astrobin: www.astrobin.com/users/Lead_Weight/
5 months 2 weeks ago #78347

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Thank you.  I have built homing the mount into my start up routine, and since I’ve starting doing that, I’ve not had issues with cord wrap.  Maybe I need to add homing after starting INDI, too.  Plate solving seems to work great.  Maybe the some of the guiding issues had to do with my polar alignment being off.  I’ve purchased a new MacBook Pro, I’ve had issues with the PoleMaster software failing (it worked fine on my old MacBook Air).  So when I tried this last night, my PA was undoubtedly off.  I have been trying 0.5 and 1.0 second exposures.  I’ll revisit that with better alignment.  Maybe it’s time to try the internal PA routine until the PoleMaster software is sorted.

I was hoping for a clear night but maybe tomorrow… thanks for the suggestions.
 
5 months 2 weeks ago #78349

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Max,

Thank you for the updated guiding settings and list of the steps you take during setup.  Sounds like I need to add homing the mount from the INDI control panel to my routine.  Plus, I’ll turn off “simulate the pier side”, too.  You mentioned that you don’t use the hand controller.  Is there an operational reason for that other than simplifying the setup?  I’ve already had the mount damage itself once (cord wrap), and I kind of like the extra assurance of having an easy to reach panic button.

Unfortunately, it’s cloudy here tonight, and so I’ll have to try again later.

Thanks again,
Greg
5 months 2 weeks ago #78350

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