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  #21  
Old 05-06-2020, 03:49 PM
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codemonkey (Lee)
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Originally Posted by xthestreams View Post
"out of the box" +/- 1.5 arc second average tracking feels pretty good to me and certainly exceeds the result I was getting from (what was a relatively lightly loaded most days) EQ6-R
To be clear, do you mean tracking or guiding?
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  #22  
Old 05-06-2020, 08:21 PM
Startrek (Martin)
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Hi Paul
I have 2 questions for you regarding the new EQ8-R pro mount -
1/ what is the distance in mm between the extended tripod feet once levelled
2/ What is the height in mm from the tripod base to the ground once levelled before you plonk the mount head on

Reason - I have 2 off EQ6-R Mounts , one at my home in Sydney and one at my weekender south coast. I’m considering putting in a Nexdome Obs at my weekender later in the year and want to make provisions for a larger mount like the EQ8-R pro Initially as a tripod mount and maybe pier mount later on in the future. I will make provisions for concrete footings etc for my EQ6-R ( distance between tripod feet is 970mm ) and hopefully the EQ8- R pro will have a similar distance between the tripod feet

Await your advice

Thanks in advance
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  #23  
Old 06-06-2020, 09:31 AM
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The_bluester (Paul)
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Quote:
Originally Posted by codemonkey View Post
To be clear, do you mean tracking or guiding?

I would assume that is tracking, On a good night I get around 0.6 arcsec guided out of my Orion Atlas (AZEQ6) which more or less shares the mechanics of the EQ6R.
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  #24  
Old 06-06-2020, 12:59 PM
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xthestreams (Paul)
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Ah, sorry yes sloppy with terminology - tracking yes, guided I found the RMS down around 0.5 on DEC, 0.8 on RA, so something's obviously slightly out of whack somewhere.

As mentioned there was a lot of high level haze around too, so the seeing wasn't that crash hot, was using a guide scope vs. OAG and again, no PPEC training done yet.

It's all been pretty rough and ready here - I hate being "that guy" but as soon as I saw clear skies it was a bit of a race to get it all up and running. Yesterday and today spent some time tuning the levelling of the pier tripod and getting the balance biased more "weights down", oddly it was a little too balanced and I think I was seeing artefacts associated with that - ran some 300 second subs (at an optimistic 2000mm FL - I know...) and for certain some oval stars, how much of that is down to the image train vs. the mount itself - in my hurry I changed more than one variable at the same time, you would think I would know better....

Summary - it's no Paramount, but not too shabby for the price and I hope will only improve with tuning.

Tonight is a bust but tomorrow promises some decent skies, minus that amazing moon...

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To be clear, do you mean tracking or guiding?
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  #25  
Old 06-06-2020, 01:04 PM
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xthestreams (Paul)
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First up, thanks for your reply - I've shown it to the missus and now I can at least say "but I've only got ONE tripod now dear" :-)

1. roughly 900mm centre to centre
2. roughly 910mm in my setup, you can raise or lower the centre column according to the manual, I've mine set so that the hinged stabilisers are roughly parallel to the ground.

Pier itself is solid, rumour is that it's Russian designed, from what I can see, by a former tank designer.

Mines inside a Nexdome, happy to send whatever measures and photos you need.

Quote:
Originally Posted by Startrek View Post
Hi Paul
I have 2 questions for you regarding the new EQ8-R pro mount -
1/ what is the distance in mm between the extended tripod feet once levelled
2/ What is the height in mm from the tripod base to the ground once levelled before you plonk the mount head on

Reason - I have 2 off EQ6-R Mounts , one at my home in Sydney and one at my weekender south coast. I’m considering putting in a Nexdome Obs at my weekender later in the year and want to make provisions for a larger mount like the EQ8-R pro Initially as a tripod mount and maybe pier mount later on in the future. I will make provisions for concrete footings etc for my EQ6-R ( distance between tripod feet is 970mm ) and hopefully the EQ8- R pro will have a similar distance between the tripod feet

Await your advice

Thanks in advance
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  #26  
Old 06-06-2020, 01:18 PM
Startrek (Martin)
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Paul
Thanks so much for your information
I was hoping the distance between Tripod feet was around 900mm , so I can design my 250mm diameter concrete pads to be 1000mm apart , that would satisfy my existing EQ6-R and a proposed EQ8-R pro mount

A few photos of inside your Nexdome would be greatly appreciated !

Martin

Cheers

PS: My Nexdome will sit on a 2600mm x 3100mm timber deck about 350mm off ground level with free standing 250 dia concrete pads , 3 for the tripod feet and one in the centre for a possible future pier mount
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  #27  
Old 09-06-2020, 08:39 AM
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xthestreams (Paul)
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EQ8-R further experience

NOTE: Edited as I think I figured out what I've done wrong, will test tonight.

Despite having a 6AM start today I used the little bit of cloud free sky last night to get a couple of hours in with the EQ8-R and it's not all great news.

For clarity, my anti-Windows stance gets me into trouble as it limits be to INDI based drivers and some of the issues described MIGHT be attributable to that, but I suspect there's something deeper going on.

First up, the Autohome feature and API is almost certainly different between the EQ8 and EQ8-R due to the lack of Freedom Find Aux encoders on the EQ8-R with the new home sensors being in place instead. Logged a bug report with teh INDI developers and have gone to SkyWatcher to see if they can shed any light, but from what I can see this might also be a problem for the ASCOM drivers - if anyone has a different experience, would love to know.

Then there's PPEC - it all started with trying to diagnose the tracking and guiding challenges I was having.

Again to be clear this is with a local FL scope (2000+mm) and the seeing during my first attempt at tracking/guiding wasn't great - how much of this has to do with the mount versus my still poor grasp of EKOS is up for debate, I am sure at least 50% of this is me.

Anyways, last night I set EKOS to guide but disabled the sending pulse commands to the mount to see how well it would track without guiding. The answer was pretty well on the E/W axis but terribly (+/- 5arcsecs) on the N/S - I am guessing the scope is too symmetrically balanced, something that will hopefully be less of an issue when the new motorised Moonlite arrives to add some ballast East-side down, until now I might try a small weight on the left hand side of the dovetail.

So, I decided to play with PPEC - did that through the INDI control panel, started training first the Dec and then the RA axis - took about 4 minutes a piece and here's where the fun started.

I enabled PPEC after training and the mount started slewing the RA axis rapidly, like it was tracking at a custom (faster than sidereal) rate to the point that it exceeded my horizon limits. I left it go as long as my heart-rate could bear and then had to switch off PPEC at which point the mount appears to be behaving normally.

Then I took at look at my OAG images and noticed it wasn't holding stars at all - it appeared that the DEC axis was going something similar albeit at a much slower rate.

So, long story short - if you're using INDI EQMOD and an EQ8-R I'd love to know if I'm the only one having this problem and if so, how are others using the PPEC feature?

I guess the same question applies for EQMOD on ASCOM.

Even shorter story, EQ8-R may still have some teething issues when it comes to direct control via USB (vs. handset)

P.S. I thought I would play around with teh handset controller and see if there was anything obvious and of course as I looked at the PEC training function I think I realised my mistake, with guiding "on" but inactive (not sending pulses) there was nothing correcting the scope and so the training was erroneous. Hopefully I can clear the training back to factory and start again tonight.

Last edited by xthestreams; 09-06-2020 at 09:04 AM. Reason: I'm a dummy!
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  #28  
Old 09-06-2020, 09:34 AM
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The_bluester (Paul)
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What is the worm period on the EQ8-R (If that is any different to the older EQ8) You would need to train the PEC for at least a full worm cycle. The EQMOD PEC trains over at least four worm cycles to average out the corrections (Might be 5) And yes, you will need guide commands to the mount to train it.

That said, there would not normally be PEC on the Dec axis, that should only be getting guide pulses to deal with the PA not being quite right or a bit of wind moving the scope off target and similar errors, it does not run continuously at a theoretically fixed rate like the RA, so periodic error is not as important.
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  #29  
Old 11-06-2020, 02:50 PM
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xthestreams (Paul)
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Belt drive on both (and I can confirm that as I removed the cowl that covers teh belt and motor system today to ensure that it was there and in good working order).

Had a really long session with the mount last night, gave it a few hours of guiding in what were reasonable skies compared to the thick cloud of the last few days.

I'm guiding internally to EKOS, not PHD2 (yet) so feeling my way compared the volumes of docs available for PHD2 - last night's session with an 8" SCT and a ED72 guide scope gave me about 0.8arcsecs RMS on RA and 0.4 on DEC which is far better than my first night.

I then moved to the OAG (ASI290mm) and after opening up the window to 128pixels had far more success in finding and keeping the star in frame this time. Got a good 90 minutes of imaging in and saw 0.6 RMS on RA and 0.2 DEC - I'm not sure about everyone else here, but I was pretty pleased - I would even theorise that I was seeing limited last night vs. the mount but I'm not the best judge of these things yet.

Moving swiftly onto the PPEC training problem. Well.....

Initiated the training again through the EKOS control panel, WHILE guiding was running (providing the feedback pulses) and again, shortly after enabling the RA PPEC in EKOS the mount goes into what looks like 50x sidereal tracking speed (from the meridian to the bump stops in 60-90 seconds - terrifying to watch even with horizon limits switched on!)

Not entirely sure how I solve for that problem other than for now, avoiding the "feature" altogether.

If anyone has any experience or thoughts with this feature with ASCOM or going the the SkyWatcher app, I'd love to hear about it.

Quote:
Originally Posted by The_bluester View Post
What is the worm period on the EQ8-R (If that is any different to the older EQ8) You would need to train the PEC for at least a full worm cycle. The EQMOD PEC trains over at least four worm cycles to average out the corrections (Might be 5) And yes, you will need guide commands to the mount to train it.

That said, there would not normally be PEC on the Dec axis, that should only be getting guide pulses to deal with the PA not being quite right or a bit of wind moving the scope off target and similar errors, it does not run continuously at a theoretically fixed rate like the RA, so periodic error is not as important.
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  #30  
Old 11-06-2020, 03:28 PM
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Merlin66 (Ken)
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Paul,
with the guiding performance you're seeing, why bother with PEC corrections?????
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  #31  
Old 11-06-2020, 04:44 PM
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I think I would agree with that. I spent some time training the EQMOD PEC, but I could not make out any discernible difference in the guiding quality. I have had nights without it when I have had 0.6 arcsec total guiding errors and sometimes minutes between corrections, and nights with it like that but jumpy, jittery nights too. I had a power outage which zeroed out the EQMOD PEC and didn't bother to retrain it after that given it means giving up on the best part of an hours good imaging time to train it.

Last edited by The_bluester; 12-06-2020 at 06:47 AM.
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  #32  
Old 11-06-2020, 11:51 PM
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xthestreams (Paul)
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Why bother with PEC?

Bloody good question! Mainly because I figured if it was there then “why not see if there’s any more gas left in the tank?” From an optimisation standpoint and the other being that RMS and absolute jumps are not the same thing, and it still seems to swing pretty wide, the average only tells part of the story.

But truthfully, now that it appears to be a bug, and one that’s potentially damaging to real world objects and gear, it’s turning into a slight obsession as I’ve gotten further into plans to go long distance remote it’s nightmare scenarios like a mount going off to crash into a pier and/or not recovering to a home position after a power failure that do my head in) (Don’t panic, this will not be the mount for that, there’s an ME lined up for that task but I am using it to shake down other parts of my workflow, Toadhall has inspired me, and scared the missus.

In other news, the controller was well behind on firmware despite being new, so assumption is that Tasso are probably sitting on original stock. Firmware update did nothing to address the bug.

Summary - lovely product but not without its teething problems as a remote ready device.

Quote:
Originally Posted by Merlin66 View Post
Paul,
with the guiding performance you're seeing, why bother with PEC corrections?????
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  #33  
Old 11-06-2020, 11:57 PM
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xthestreams (Paul)
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Makes perfect sense and now that I’m seeing much better numbers after a few nights I am more confident using the platform at the FL I’m targeting.

Interesting that the swings with guiding were so erratic first few nights and then settled down. I changed too many variables at once to be sure, but I am starting to think I’d set the box for my OAG too small and the guider/mount/scope started chasing the seeing and making it worse.

Such are the silly things I do. The downside of being a n00b.

Quote:
Originally Posted by The_bluester View Post
I think I would agree with that. I spent some time training the EQMOD PEC, but I could not make out any discernible difference in the guiding quality. I have had nights without it when I have had 0.6 arcsec total guiding errors and sometimes minutes between corrections, and noghts with it like that but jumpy, jittery nights too. I had a power outage which zeroed out the EQMOD PEC and didnt bother to retrain it after that given it means giving up on the best part of an hours good imaging time to train it.
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  #34  
Old 12-06-2020, 07:06 AM
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I can't comment on Ekos and it's guiding performance, but if you switch to PHD2, the guiding assistant is a quite useful tool. I run it once on most nights. What that does is disable guide output and monitor the star position to nail down the seeing related movement of the star to recommend the minimum move settings, then unless you untick the box it measures the Dec backlash and calculates a suggested backlash compensation amount. It takes about 5 minutes and I have found it handy to dial it in to decent starting settings fairly quickly. Depending on the focal length of the imaging scope, I have generally found less active guiding to be better than more. IMO, if the guiding RMS is markedly less than your pixel scale all you are likely to achieve by trying to tighten up the guiding with more aggressive corrections is blobby stars as you chase the seeing.

The RMS is really what matters if everything is functioning OK. Unless you have spikes in the tracking errors (Indicating a probable mount issue) or unless the bigger deviations are greater than your pixel scale or are common (In which case the RMS will suffer as well) I reckon the most likely thing is to go down a rabbit hole chasing what turns out to be seeing effects. It is why guiding can be superb one night and awful looking the next. That is what happened to me last month. One night I had a guiding graph that looked like my mates typical Tak mount graph (i.E. a "He's dead Jim" ECG plot) and the following night it was nothing like as good. I did not even physically touch the setup between nights, the only thing that changed was the sky.
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  #35  
Old 12-06-2020, 07:13 AM
Startrek (Martin)
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Paul,
The guiding numbers on your new EQ8-R are excellent, both my EQ6-R’s in Sydney and South Coast on an average night of seeing guide around 1 arc sec , down south on a good night 0.80 to 0.90 and under excellent seeing 0.75 to 0.85 and that’s with 15kg on board , 1000mm FL , a guide scope and no PEC
If your getting 0.6 arc sec and below out of the box on an average night of seeing then that is excellent , maybe on an excellent night you will get down to 0.4 to 0.2 arc sec which is ridiculously good. I too wouldn’t worry about PEC
I’m still getting round stars at 1 arc sec error pushing +5 minute subs for hours and hours at my focal length
2 weeks ago I imaged the keyhole with a 2 x Powermate which gave me a 2000mm FL and 15 kg on board pushing 5 minute subs for hours and stars were pinpoint. That EQ6-R out of the box is a proven performer as I’m pushing its limits with 15kg on board
Your EQ8-R is definitely in a class of its own
Cheers
Martin
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  #36  
Old 12-06-2020, 02:16 PM
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xthestreams (Paul)
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Thanks Martin, agreed the EQ6-R is a lovely mount as I managed similar results with mine, if I had the money to keep both I would have - great for more portable requirements!

I've attached last night's plot for LOLs - Melbourne treated us to a lovely mix of scattered cloud, high level haze and generally the type of night that makes you wish you had a different hobby - there's almost no doubt in my mind I was chasing the seeing last night, so this one's more of a worst case situation. As soon as I have the time and patience to dial in PHD2 and connect it to EKOS I'll post something that it more familiar to the group and we can start to compare more meaningfully.

I *dream* of a "she's dead Jim" trace... (and a 16xxx series camera with a fully populated filter wheel attached to a 16" Planewave somewhere in the Coonabarabran area and a VERY understanding partner)

Quote:
Originally Posted by Startrek View Post
Paul,
The guiding numbers on your new EQ8-R are excellent, both my EQ6-R’s in Sydney and South Coast on an average night of seeing guide around 1 arc sec , down south on a good night 0.80 to 0.90 and under excellent seeing 0.75 to 0.85 and that’s with 15kg on board , 1000mm FL , a guide scope and no PEC
If your getting 0.6 arc sec and below out of the box on an average night of seeing then that is excellent , maybe on an excellent night you will get down to 0.4 to 0.2 arc sec which is ridiculously good. I too wouldn’t worry about PEC
I’m still getting round stars at 1 arc sec error pushing +5 minute subs for hours and hours at my focal length
2 weeks ago I imaged the keyhole with a 2 x Powermate which gave me a 2000mm FL and 15 kg on board pushing 5 minute subs for hours and stars were pinpoint. That EQ6-R out of the box is a proven performer as I’m pushing its limits with 15kg on board
Your EQ8-R is definitely in a class of its own
Cheers
Martin
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  #37  
Old 12-06-2020, 02:56 PM
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Just once, my guiding has looked like this with the AZEQ. Not the night before, not the night after and I didn't touch the gear after initial setup on the first night. 0.51 arcsec RMS.

There were times you could not see a correction on screen. 0.6 to 0.8 arcsec is more typical and 1ish is not that unusual. But that is still around half of my pixel scale.
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  #38  
Old 12-06-2020, 08:40 PM
Startrek (Martin)
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Paul ( The bluester )
I crunched some payload numbers on the Evostar 72 and your guide scope plus misc AP gear and ended up with around 7.5 to 8.0 kg on your AZEQ6 which is around 50% loaded on an AP payload rating. I think your AZEQ6 has a kilo or two of spare additional AP payload capacity compared to both my EQ6-R mounts
So it’s no wonder your getting superb guiding numbers at around 0.50 to 0.60 arc sec on your mount. I’m actually overloaded ( AP payload rating wise ) at 15kg on my EQ6-R Mount. Full load AP payload rating on my Mount would be in the order of 13kg to 14kg ( hence why I can never get below 0.80 arc sec on a night of excellent seeing )
NB: From numerous forums I’ve read, a figure of 60% of the maximum recommended payload rating of a mount is a good gauge for recommended AP payload rating

My assessment could way off base ?

Your thoughts on my numbers ?

Cheers
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  #39  
Old 12-06-2020, 09:10 PM
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You mean with the SVX80 on there? That guide graph was with the SVX80 and the Evostar piggybacked on top as a guidescope while I was waiting for a new OAG assembly to arrive. I didn't ever weigh the whole kit but the SVX80 is about 5KG on it's dovetail and riser setup, plus odds and sods fittings and the Evostar on top. 8ish KG is probably about right.

I am not really sure if the AZEQ has any real world payload advantage over the EQ6 mounts, though the counterweight shaft is thicker (So more rigid) which would help to some degree I assume. I am looking at replacing mine with an EQ6-R to be honest as balancing the AZEQ type mounts for AP is a pain. I would love a bigger and heavier mount like the EQ8-R or a CEM60 but budget says no.

I did manage to get round stars out of my SCT with reducer at about 1500mm focal length on this mount for a couple of 20 minute test subs but I never noted down the guiding figures. I would bet they were not half arcsec, and the stars might have been round but they would probably have been a bit bloated.
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  #40  
Old 12-06-2020, 09:39 PM
Startrek (Martin)
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Yes sorry I meant the SVX80 scope
If your considering buying an EQ6-R Mount soon make sure it’s not old stock as the newer model has the additional USB2B port on the mount for EQ direct via Ascom. The handcontroller also has an additional USB2B connection just for firmware updates
I have both older and latest models but still using the old shoestring EQ direct cable for both to run EQMOD, StellariumScope and Stellarium. I might try out the newer mount with a USB cable soon as I found the procedures on CN a few months ago , haven’t been bothered to try it yet
Good luck with your future purchase !
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