Mounts with encoders - guiding

SFn8CieR

Hi,
I just purchased an Ioptron CEM70EC2 and Polar aligned it with my ASIAIR Plus (AA+). Its not perfect but pretty close. I did some autoguiding last night on various objects to see how the AA+ guided. I was hoping that you guys could take a look and my logs and give me some advice. I am using the AA+ with my 72ED Scope just to get some experience with guiding.
It calibrated pretty well I think, and started guiding using multiple stars. I got mixed results in terms of rms figures, from 0.3 to 1.7 and I could not seem to get it consistent when I tried guiding in different places.

I also tried unguided and was getting round stars at 3 mins and not so round at 5 mins.
Is there setting in the AA+ for using Mounts with Encoders? Also what would be the procedure to set up guiding with this mount?

many thanks..

phd2-guidelog-2023-11-05-204347.txt

367kB

cheers.
Nick

Tech@ZWO

SFn8CieR Turned off the encoder to try. or increase the guide exposure time to 10ms.
Encoder and guide may affect each other.

Kevin_A

Do you have to turn off the encoders when autoguiding so they do not fight each other?
I thought so but not sure with newer mounts.

w7ay

Kevin_A I thought so but not sure with newer mounts.

The RST-135E can be autoguided wth its Renishaw encoder turned on.

Chen

Kevin_A

w7ay not sure about iOptron mounts.
I know the older ones did not have a good time with it.

SFn8CieR

Hi Everyone,
Thanks for your replies. I did not realise that I needed to go to the forum to get your responses as I thought they would be emailed to me, so apologies for not responding sooner.

The Encoders on my new Ioptron CEM70EC2 Mount cannot be turned off as far as I know. I have been using 2 or 3 secs for Guiding Exposure time, so its bumping the mount too often. From what I understand the Encoders reduce the Mounts PE so it runs accurately and the Guiding Software should only occasionally bump the Mount where needed to keep it in line, so increasing the guide exposure time makes a lot of sense.

Also what calibration Step and MAX RA and DEC Duration figures should I use on the ASIAIR's Mount setup page?
The current ASIAIR defaults are 2000, 2000, 2000 and I have read that if you are using a ZWO mini Guide scope with FL=120mm these figures should be in the vicinity of 8000 to 10000? I know when you do a calibration, these higher values move the mount more than if you use the default 2000 values and requires less Steps to calibrate. However if you are using an OAG with the FL of the Guider being the same as the FL of the scope, then these figures should be in the range of 250 to 500ms. I would be interested to know your thoughts on all of this.

Also when guiding, what aggression values should I use? I would presume using lower figures such as 10 to 25% would keep the autoguiding bumps down to a minimum? Also with the Guiding Rate, should I try different values 0.25, 0.5, 0.75 x Siderial to see which gives better RMS values or just leave it at 50%?

My aim is to get this mount properly guiding with the ASIAIR and I really appreciate your feedback on this.
Cheers..
Nick

SFn8CieR

I forgot to mention that I am currently using a SW ED72 Scope with native focal length, with ZWO guidescope and camera, and once I have sorted out autoguiding my double encoder mount with this setup, I will try autoguiding my C11 with 0.63 Reducer and OAG, so autoguiding will be more critical then.
thanks.
Nick

kisslija

Nick,

Were able to get the setting figured out? I had the same experience with the AA+ and the CEM70EC2. The mount plays great with PHD2 when connected directly. There is something about the AA+ that throws it into a frenzy.

Jeff