It appears that the latest version of SynScan for EQ mounts (v.3.32) has a bug in its polar alignment procedure.
The routine seems to be assuming a northern hemisphere setup with the mount pointing north. During polar alignment the altitude ("elevation") error is being corrected nicely and can be diminished after just a few steps. The azimuth error however roughly doubles with each run of the procedure.
This can be worked around during the polar alignment routine by bringing the alignment star as close as possible to the crosshairs via the altitude adjustment screws first and then using the azimuth knobs to not bring the alignment star into the crosshairs but doubling its distance from it.
After several public betas it's disappointing that this bug made it into the release and I hope it gets squashed soon. If I can find a feedback link for SkyWatcher I'll report it to them.
I noticed it too some time back. If I did a poor alignment, leading to an average GOTO, I would run the polar realignment routine, which was FINE for alt, but made it significantly WORSE in az. Where I was close to a DSO before, after the realignment it was WAY off.
I thought I'd just have a look on the forums while I waited for the download. Saved me banging my head against the ground tonight when it all went wrong!!!
I've just packed up after a frustrating night of fighting with the mount. There is another new "feature" I didn't notice before.
After successful 3-star alignment (and ignoring a small polar alignment error), the mount slews to objects I tell it to go to, and upon arriving there (pretty much spot on) slews away by about half a degree, slews back to the object and goes back and forth a couple of times until it stops half a degree away from the object. What's that about? It only appeared to happen for objects in the north to north-east (around Orion and Taurus tonight).
I thought it might be some sort of backlash compensation, so when it overshoots the target it goes back and tries to come again (in order to approach from the right direction). But it should eventually make it to the target and not stop way away from it.
What is a SynScan firmware version people are happy with? I might re-flash my controller with that one to get some reliability back.
I'm on 3.30 beta and I seem to remember that they said they'd fixed the northern hemisphere issue that was present in the 3.28 beta... obviously not though as the first time I tried the polar align routine I had a similar experience to you. I gave up and went back to drift aligning.
I've not noticed the slewing issue though.
Hi, I'm from Argentina and I've the same problem with the v3.32. I also wrote to "contact us" and they just send me a V3.33 beta to try.
As soon as I try it, I'll inform you. Right now I'm on 3.28b15, and the polar alignment works ok (if anyone wants the file, let me now).
Agustin
Dear Agustin,
Thank you for your inquiry.
Could you please take a look at the attachment (for firmware version 3.33 beta 01) ? We had updated the firmware regarding the polar alignment in the south hemisphere issue. Could you please test the firmware again with the new attached code and see if the polar alignment function works properly? Could you please also let us know whether the result of your test?
Thank you very much again for your interest in our products and inquiry!
hi everybody,
I recently bought a used HEQ5 Pro GOTO, and it is running
version 3.20. This seems to be working fine, except that some of the alignment star choices it gives me are either just above the horizon,
and hidden behind low trees, or have obscure names, and are not listed in Norton's list of 156 named stars.
raymo
I have just tried the Synscan 3.33B01 everything looked fine for the 2 star align. It was pointing nicely and then I tried the polar align... miaplacidus was the target of choice and it slewed to within a short distance of the star needing minor correction. When the routine ran it immediately tried to slew to 354 degrees and bury itself to the north . NOT the few Minutes of correction that it needed . It would seem that 3.33 is a bust as well. I will now go back to 3.28 which works.
Even though my dec issues continue, I did run 3.33B01 last night, and for a 3 star align, it offered me a LOT of stars! Nice change, compared to the few it used to offer in 3.28 etc.
Didn't try the realignment routine, for frustratingly obvious reasons.
Seeing it has all new firmware now, I thik I can rule out hand controller issues, and that leaves the motor or the board (AGAIN).
After reverting to the 3.28 beta, I performed a 2 star alignment successfully and then went to the polar align. This time the error was smaller than stated with the 3.33b? After adjusting I placed it back to home and then did another 2 star align. I expected it to nail Sirius in the cross hairs but for some reason I had to make adjustments. After the align I once again performed the polar align and instead of minor moves I had to make a significant az alt align?? I spent some time getting it right and watching for drift. I eventually was happy and confirmed the adjustment. I put it back to home and asked it to goto a star and it missed again? Apart from the strange goto problem the polar align seems solid and whilst imaging Jupiter it stayed near the center of a 640 x480 pic on a 1/3" chip for more than 10 minutes with no guiding at all just the mount tracking. Not perfect but then it is a beta!
I hope skywatcher can resolve these problems as a fully working version of syncscan would be fantastic.
First time use in guiding! No other polar alignment used than the sysnscan from 3.28b. 4 hours of guiding with a near perfect result. I did not even do any drift alignment or anything.
SynScan polar alignment bug
. NOT the few Minutes of correction that it needed 
. It would seem that 3.33 is a bust as well. I will now go back to 3.28 which works.
