EQ8 problems

[Ken]

After two nights of not being able to locate any objects I need some help. After performing the auto homing feature and doing a two star align the hand control says align successful I press enter and it says caution value of previous NPE is applied.
The mount slews to the object then as the RA drive is slowing down to stop it speeds up again then slows down then speeds up about 3 or 4 times putting it way past the object. If anyone knows what the issue is I would be most grateful.
Clear skies Ken.

[Startrek (Martin)]

Some basic questions
Is the mount perfectly level ?
Have you set your altitude correctly for your location ?
Is the mount and scope balanced
Have you set your home position correctly ?
Are you polar aligned before this happens ?

Sorry to ask silly questions but they all relate to your issue in some way

[The_bluester (Paul)]

Is is speeding up and slowing down, or is it moving in different directions? I have noticed that with the Goto dob I have (Also Skywatcher) when it does a goto tends to slew to the rough area (Often with the target visible in the EP) stop, slew away briefly at high speed then back again slowly and it repeats this routine a couple of times before settling.

If you send it to the home position does it end up pointed at the pole?

[Ken]

Thanks Martin and Paul for the reply, the mount is polar aligned in a observatory it had two scopes side by side so I had a 90 deg. offset programed in which let the goto work correctly as the home position.I manually park it on its side so I can close the roof but the pointing was getting a little off target so I did the auto home bit added 90 deg. offset then the tube moved to point at the south pole as it should. I completed the two star align, the second star was dead center in the camera with no corrections but when I hit enter the warning about NPE came up what ever that is? After the object slew missed I sent the mount to the home position and the RA shaft was about 30 deg. from being strait down.
Last night I removed the side by side saddle plate and just had a single normal setup did every thing again removing the home offset but got the same error message, the mount still had the same problem. Last resort I cancelled the factory settings and reinstalled my settings but still ended up with the same result.

[Wilso]

Hi Ken,
Just did a quick search, this might help (there were a few others that came up)
stargazerslounge.com/topic/313977-skywatcher-eq8-synscan-controller-problems/

[Ken]

Thanks Darren I will read that, just came in from the mount. I have some success tonight did the two star align then goto Acrux which was a small hop from the last align star it missed it by a few deg. I tried a 1 star align using acrux and it moved it to the centre so it knew ware it was then sent mount to home position again the counter weight shaft was about 30 deg from straight down. I disabled the aux encoders and did a two star align, after that it found all the objects I sent it to. Tonight there were no multiple slews like the last two nights? I guess I am happy that it is usable again even though something is not quite right.
Clear skies Ken.

[The_bluester (Paul)]

Seeing your mention of the previous NPE being applied sent me googling today, it seems that it is a message that can generally be ignored. It is supposed to be a correction for non orthogonality between the two axis and it will only be re calculated on a three star alignment.

I use my AZEQ6 (The Orion version but it is quicker to type AZEQ6) with ASCOM and manually home it before use with ASCOM, but my sons goto dob pops that message up pretty much every alignment.

[Ken]

Thanks Paul that makes sense I have probably seen that message before and not taken any notice of it, the multiple slews in RA even running till it hit the limit stop spooked me into looking at every thing.
I have never done a three star align.
Clear skies Ken.

[Startrek (Martin)]

On both my HEQ5 and EQ6-R mounts with Synscan the warning NPE comes up after a 2 star alignment , I then press enter and it then gives you the PA alignment error in arc minutes and seconds for both Elevation and Azimuth , I take note of those numbers and then press Polar Alignment , pick a PA star , slew to it , centre it press , enter then the mount goes through its PA routine both in Elevation and Azimuth. The mount moves away from the PA star and comes back near it , you then centre it using the Altitude bolts , press enter and it moves away again and comes back near it , you then centre it as close as possible to the Altitude position previously using the Azimuth bolts press enter then do another 2 star alignment , then the NPE warning comes up , then press enter and it gives your PA error again for Alt and Az
You keep doing iterations until you get the error down to under an arc minute
That’s my Synscan Star alignment and PA procedure
Whooosh .......

[Ken]

Thanks Martin I don't use this mount much, it is permanent on a home made pier, the polar align is good but probably not perfect I think it was originally drift aligned using a ccd camera. I noticed those error numbers after 2 star align, any way there is a lot in the Synscan manual I should learn.
Clear Skies Ken.

[Adox (Adriano)]

1. Turn off the auxiliary encoder.


2. Eventually try to reinstall the motherboard firmware


3. Lastly, chance the motherboard.

[Ken]

I think it is now working OK with the Aux encoders turned off will do some testing when this wind goes away.
Clear skies Ken.