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  #21  
Old 15-09-2020, 10:06 AM
jahnpahwa (JP)
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Originally Posted by The_bluester View Post
Well, I think I will finish off for now. I have had two more nights and it has been a pain free experience. Last night was around 1" guiding, which I think is perfectly acceptable out of a 120mm focal length guider, particularly when I am imaging at about 1.6" per pixel, every sub I shot last night had round stars and after all, that is the point. I need to set up under a moonlit night soon (So as not to throw away good dark sky imaging time) and just fiddle with the guiding as I am sure I could improve it with tweaks and fettling, but even as it is, it is performaing perfectly well.

The only "Issue" I have come up with I am going to document with some logs and feed back to iOptron via my vendor (As they might get some attention) as there appears to be a minor firmware issue. There are various selectable park positions, none of which I like, but you can set a user defined park position. The issue is that if you set the "home" position (Counterweights down, pointed at the pole, my preferred park position) as the user defined park position it does not park properly, it goes to the correct position but then keeps tracking. Offset the user defined park by even a degree or so and it parks and stops properly. Small beer if that is the worst thing it ever does.

Aside from that, I spent much of last night fiddling around and sent goto after goto after goto and it just did what it was told.
Sounds like a good outcome
I'd be keen to keep reading your thoughts here if you care to keep documenting them, especially with the fettling you do and what that achieves
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  #22  
Old 12-10-2021, 04:02 AM
BinaryBill (Bill)
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Hi Paul,
Any updates on the mount? I also have an AZEQ6 GT and have it tracking really well (0.4-0.7) all night but was after a little more carrying capacity, the CEM70G is top of my list.
Cheers,
Bill.
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  #23  
Old 12-10-2021, 10:09 AM
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The_bluester (Paul)
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I am quite happy at this point. There were a few early software and firmware niggles, some resolved, some easy to work around. There is a new revision of the motor control boards that reduces a tendency they used to have to oscillate slightly on the RA axis (Seemed to be as the motors went over each full step they would "Snap" to the full step where the micro steps in between did not) The park position issue listed above remains, I just selected one of the preset park positions instead and it parks perfectly every time.

On a still night with a 10"F4 newt on it using an OAG I regularly see 0.5" or better, it was running last night and PHD2 was reporting 0.36" total RMS using the PHD2 PPEC algo.

Once I worked out it's minor peculiarities, it just works.
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  #24  
Old 13-10-2021, 08:56 AM
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With the Park position - Ioptron support told me that you cannot park in the Zero position - you need to be slightly off Zero before it will park. Iv'e confirmed this behavior.
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  #25  
Old 13-10-2021, 09:07 AM
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I've had two CEM70's - first was a non G, and second was a G. Both were/are very good performers from my POV.

Niggles:
- iPolar is a great system in theory, but at least on my copies of the mount not accurate enough to use by itself.
- method to attach the mount to tripod/pier is annoying
- I wish the knobs to tighten the OTA were on the opposite side
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  #26  
Old 13-10-2021, 09:44 AM
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Originally Posted by toc View Post
With the Park position - Ioptron support told me that you cannot park in the Zero position - you need to be slightly off Zero before it will park. Iv'e confirmed this behavior.
I never got a response from iOptron but I did work that one out for myself. At the time the commander software tended to "loose" park positions including custom ones and default to what is a very strange (But safe) park position, so in Voyager I was sending it home instead of parking it. It seems to retain your selected park position properly now so I park it in one of the pre defined ones as I got used to it parking there. The trap to sending it to the home position instead of parking it is if the guider is not shut down and sends a guide pulse it restarts tracking! I came up with a work around in a Voyager script to ensure that the guider was stopped any time it was sent home, but when parked it does not respond to guide commands or restart tracking.

The default park position if it lost it's brains is 0-0 alt-az which would make sense in the northern hemisphere, but here it results in the scope being parked with the counterweight bar horizontal, scope on the east side of the pier and pointed backwards!

I have found the ipolar to be accurate enough to avoid field rotation with 20 minute subs at 1100mm focal length. The fiddly attachment method to the pier does not honestly bug me though moving the altitude locks 10mm would be better. I cut the handle off a long, ball headed allan key and that makes it easy to start the bolts, only needing the original to finally tighten them. Funny enough I never noticed the saddle bolts being a pain on the side they are, but now I think on it it would be easier of they were on the other side. I tend to stand on the east side of the mount and hold the scope with my left hand, reaching around to the far side with my right to do them up.
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  #27  
Old 16-10-2021, 03:50 PM
metalage (Adrian)
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This is a very interesting thread! I have recently done some extensive research on these CEM70 mounts and intend to purchase one with the NUC option in a few weeks time. Mainly as I can swap this out at any time should connection standards change and all NUCs should have stable USB 3 Ports.

Glad to hear the iPolar works allowing to easy and fast setup. This was another bonus which led me to the mount and will be much faster than drift aligning my current HEQ5 Pro.

Do people here have advice on the base they use? Iím tossing up between the iOptron tri pier or the heavier 360 version that has an anodised paint finish?
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  #28  
Old 16-10-2021, 08:58 PM
Sitt (Simon)
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Originally Posted by metalage View Post
This is a very interesting thread! I have recently done some extensive research on these CEM70 mounts and intend to purchase one with the NUC option in a few weeks time. Mainly as I can swap this out at any time should connection standards change and all NUCs should have stable USB 3 Ports.

Glad to hear the iPolar works allowing to easy and fast setup. This was another bonus which led me to the mount and will be much faster than drift aligning my current HEQ5 Pro.

Do people here have advice on the base they use? I’m tossing up between the iOptron tri pier or the heavier 360 version that has an anodised paint finish?
I use the Tri-Pier 360 which is very stable plus should I upgrade mounts down the track I'm future proofing myself. One mod that I recommend is getting a pier plate adapter as the standard mount to pier fitting is very fidly. I have the CEM70EC btw with guiding at around 0.23-0.30 RMS Error on average
https://www.siderealtrading.com.au/p...adapter-plate/
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  #29  
Old 17-10-2021, 08:51 AM
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How does the mounting method change with the plate (I have one of those too on my pier but it uses the original attachment method on the mount itself) I honestly don't find the mounting method overly fiddly, and I set mine up night by night. I cut the L end off a long ball headed allan key to suit the mounting bolts and it allows me to start ans spin down the mount bolts easily, then I just nip them up using the original allan key that comes with the mount.

Regards the tripier versus tripier 360, if the 360 is all anodised finish then it will probably stay looking nicer for a lot longer than the painted finish parts on the standard one. Do the legs fold up in a way as compact as the standard one? On the standard one you remove the bottom portion of the legs and stow them inside the pier which makes it smaller to store.
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  #30  
Old 17-10-2021, 11:17 AM
Sitt (Simon)
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Originally Posted by The_bluester View Post
How does the mounting method change with the plate (I have one of those too on my pier but it uses the original attachment method on the mount itself) I honestly don't find the mounting method overly fiddly, and I set mine up night by night. I cut the L end off a long ball headed allan key to suit the mounting bolts and it allows me to start ans spin down the mount bolts easily, then I just nip them up using the original allan key that comes with the mount.

Regards the tripier versus tripier 360, if the 360 is all anodised finish then it will probably stay looking nicer for a lot longer than the painted finish parts on the standard one. Do the legs fold up in a way as compact as the standard one? On the standard one you remove the bottom portion of the legs and stow them inside the pier which makes it smaller to store.
So, if you adapted your Allan Key to suit then you must have found iOptron's method of securing the mount to the Pier fiddly?
When using the Adapter Plate, it’s a simple case of 4x bolts with easier access than iOptron mounting method. The mount is permanently fastened to the Adapter Plate via the two screws in the base of the mount. Its then a simple case of removing the 4x bolts and lifting the mount and adapter plate as one. A lot faster and nowhere near as fiddly.

The legs of the 360 don't detach like the smaller version, they fold along the Pier's length for storage. I've never used the smaller Pier but by all accounts the Tri-Pier 360 is a lot more robost as its max payload is 165kg whereas the Tri-Pier has 100kg payload

Last edited by Sitt; 17-10-2021 at 11:28 AM.
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  #31  
Old 17-10-2021, 05:48 PM
metalage (Adrian)
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Interesting about the adapter plate. Thanks for the link, I’ll look into that tonight. So you are finding the EC version’s performance really good then. From what I read there was early problems with EC versions and PHD when guiding. You didn’t experience any problems with this? On the Face of it you would think that an encoder to minimise PE on the RA axis would be a really good thing but from some of the online stories (mostly with the CEM60 mid you) it has made me nervous about purchasing one.

Looks like the 360 version will be the way to go . Thanks.
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  #32  
Old 17-10-2021, 07:58 PM
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So, if you adapted your Allan Key to suit then you must have found iOptron's method of securing the mount to the Pier fiddly?
When using the Adapter Plate, itís a simple case of 4x bolts with easier access than iOptron mounting method. The mount is permanently fastened to the Adapter Plate via the two screws in the base of the mount. Its then a simple case of removing the 4x bolts and lifting the mount and adapter plate as one. A lot faster and nowhere near as fiddly.
I would call it somewhat fiddly, but not enough to rearrange my pier to be taking the adapter plate off the pier instead of the mount off the adapter. Even with a normal allan key I only find it about a minute or so of work to put the mount on the pier, just it is quicker and easier to start the bolts and run them down to finger tight with a straight ball head key.

I am thinking of buying a tripier for when we can get back out to star parties, I did have it set up to mount on the tripod from my old CPC925, but I remounted and sold that scope. I doubt I will ever top 100KG of load so I will probably buy the regular version not the 360, it is a fair chunk of money for what for me would be functionally identical, just prettier.
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  #33  
Old 18-10-2021, 12:26 PM
Sitt (Simon)
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Interesting about the adapter plate. Thanks for the link, Iíll look into that tonight. So you are finding the EC versionís performance really good then. From what I read there was early problems with EC versions and PHD when guiding. You didnít experience any problems with this? On the Face of it you would think that an encoder to minimise PE on the RA axis would be a really good thing but from some of the online stories (mostly with the CEM60 mid you) it has made me nervous about purchasing one.

Looks like the 360 version will be the way to go . Thanks.
No problems with PHD2, everything works as it should. Attached screen shot of PHD2 taken from my last session.
Attached Thumbnails
Click for full-size image (PHD2 Guiding.jpg)
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  #34  
Old 18-10-2021, 12:50 PM
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No problems with PHD2, everything works as it should. Attached screen shot of PHD2 taken from my last session.
good grief, that is impressive guiding!!
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  #35  
Old 18-10-2021, 04:48 PM
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Wow, that is pretty flash looking guiding. I had heard the issue was with the encoders output more or less over riding the guiding. People were reporting behaviour like PHD would make a correction, then the mount would come back again. With guiding like that you would have to say it looks like they have the encoders playing nicely with external guide inputs now. I could never see why they shouldn't work right, unless they implemented them really strangely, guide inputs are really no different to pressing a key on the hand controller.
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  #36  
Old 18-10-2021, 04:56 PM
Sitt (Simon)
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Originally Posted by The_bluester View Post
Wow, that is pretty flash looking guiding. I had heard the issue was with the encoders output more or less over riding the guiding. People were reporting behaviour like PHD would make a correction, then the mount would come back again. With guiding like that you would have to say it looks like they have the encoders playing nicely with external guide inputs now. I could never see why they shouldn't work right, unless they implemented them really strangely, guide inputs are really no different to pressing a key on the hand controller.
I found the key was long exposures in PHD2, I typically expose for 6-7 seconds. Don't get me wrong, the mount isn't without its flaws as I'm sure you found but overall I'm pretty happy.
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  #37  
Old 19-10-2021, 08:51 PM
metalage (Adrian)
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That is amazing guiding! Thank you for sharing the graph. What do you experience with guide camera exposures sub 6 seconds? Do you see oscillations in the guiding graph etc.?

Last edited by metalage; 19-10-2021 at 09:05 PM.
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  #38  
Old 19-10-2021, 10:15 PM
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That is amazing guiding! Thank you for sharing the graph. What do you experience with guide camera exposures sub 6 seconds? Do you see oscillations in the guiding graph etc.?
Shorter exoposures increases Total RMS Error
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  #39  
Old 20-10-2021, 06:38 AM
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I was actually wondering which would give better real world results. I was just digging in to if I can run two instances of PHD2, one connected to my OAG camera and one to the inbuilt iGuider cam and guide it via various settings on the OAG and monitor the real world behaviour via the other.
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