Pier

Hi id like to know few things, some days ago i started to use nina for the first time and so i have no real experience with it, except this i have a whole fuctional rig, in fact usually my average tracking is below 0.2" as tot error or 0.5/0.6" as rms, even tho im loading 8kgs on a 12.7 kg payload mount, still this aint the issue, ive got the first issues when i tried the 3 star PA and many times it failed to platesolve, i guess it was because dslr gain was too low and even exposure and later on i fixed it, the real issue lies here, when i wanted to go image m1 and sent the pulse to slew and center, nina istantly told me as error arithmethic overflow operation, and if i wouldve ignored me platesolve wouldve told me no stars in field of view, now a thing i noticed yesterday was that i set the wrong camera parameters but it was because tbh wasnt specified very well, no measuring unit asked so i didnt know if it wanted to know pixels in whidt and height or size in mm, however yesterday i fixed this too, now unluckly i its always rainy and cloudy but idk if changing the parameters would allow the pulse to arrive regularly without giving issues, even because if i sent just the pulse from nina to mount to slew it wouldve worked! I'll attach a log abt that session, please let me know, i really have no idea how to get over this.

Thats supposed to be the part of the nina log where the issue is:

024-02-21T21:08:14.1196|ERROR|AscomTelescope.cs|SlewToCoordinates|717

ASCOM.DriverException: Overflow di un'operazione aritmetica. ---> System.OverflowException: Overflow di un'operazione aritmetica.

   in ASCOM.iOptron2017.Telescope.(Boolean )

   in ASCOM.iOptron2017.Telescope.SlewToTargetAsync()

   --- Fine della traccia dello stack dell'eccezione interna ---

   in ASCOM.DriverAccess.MemberFactory.CheckDotNetExceptions(String memberName, Exception e) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:riga 637

   in ASCOM.DriverAccess.MemberFactory.MethodTargetInvocationExceptionHandler(String memberName, Exception e) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:riga 685

   in ASCOM.DriverAccess.MemberFactory.CallMember(Int32 memberCode, String memberName, Type[] parameterTypes, Object[] parms) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:riga 421

   in ASCOM.DriverAccess.Telescope.SlewToCoordinatesAsync(Double RightAscension, Double Declination) in C:\ASCOM Build\Export\ASCOM.DriverAccess\Telescope.cs:riga 1216

   in Castle.DynamicProxy.AbstractInvocation.Proceed()

   in Castle.DynamicProxy.AbstractInvocation.Proceed()

   in NINA.Equipment.Equipment.MyTelescope.AscomTelescope.<SlewToCoordinates>d__143.MoveNext() in C:\Projects\nina\NINA.Equipment\Equipment\MyTelescope\AscomTelescope.cs:riga 0

1 hour ago, PhilB61 said:

Doesn't this mount use the spring loaded worm block like the CEM series? Unless it's actual free play, ie movement with almost no force applied, which it doesn't look like to me, then what you are actually doing by trying to rotate the mount is just causing the worm to ride up slightly on the worm gear and compress the preload spring. Unless you have problems with star shapes or guiding I wouldn't worry it's not a fault. If you really do have excessive backlash then the mount manual has instructions for adjusting in the appendix section.

Yes It does, it doesnt have free play in fact, just if i apply a decent force on the ra axis it slightly wobbles, ok then i'll just wait until i get the guide camera and see how the total error is!

56 minutes ago, Elp said:

 

This is exactly what I find with mine.

It's still the best tracking mount I've ever owned.

Well, if it's like he said then i should adjust the mesh, guess that's the probable issue here

59 minutes ago, SteveNickolls said:

Hi, the RA clutch knob is meant to be either in the fully locked or loose position to let you move the payload in RA but you have to get the payload/counterweight just right before locking again else you can think the RA is properly locked but it isn't and there's some wobble.  You can feel if the counterweight is either pointed down to the ground or at 90 degrees to polar align with. If there's any play it's not properly in position. Hope this makes sense. Perhaps another way to explain it is the RA lock knob can sometimes lock but not be propetly locked giving rise to the wobble.

If the mount's RA is not properly locked it will throw out your mount's 'Zero Position'.

Cheers,

Steve

Well idk about this, the clutch always been locked and i knew already those things, however the wobble is there if i put mount in 0 position, 180° or whatever you want, idk if its a maybe loose screw because i don't even know where i should check those, i saw abt cem26 but couldnt find anything for the gem28

1 hour ago, Elp said:

Have you used the mount yet, if not how do you know if it's an issue? The gearing will be biased to gravity in one direction east or west due to the load, the fact your load in is home position doesn't make a difference. Mine wobbles ever so slightly too, which is why I made reference to the axis locking knobs, you have to be sure they're locked right as they're not like a light switch on and off, there's a slight 1-2mm difference between the lock knob still being in a free state to being truly locked.

What you're referring to is backlash, most if not all mechanical gearing has this so it doesn't seize up.

If you do a search for "ioptron gem28 internal" an ioptron result comes up with a pdf for worm gear adjustment, it may or may not be relevant to your issue. But as questioned, if it works is there really an issue?

Hi, i was able to make the mount work 3 times because i always used to polar align in the wrong way but yea i never had real issues with it, thing is i just noticed this yesterday and so i started concerning i couldve maybe done something, the locking switches are always on and i noticed just with that on otherwise mount head feels steady and smooth, i worry about that because i use an RC ota on it so if i can improve tracking it's always better than leaving it as it Is, still i would like to try check tracking on phd2 but my guide camera didn't arrive yet so i can't do anything of this kind!

1 minute ago, Cornelius Varley said:

You posted two near identical threads, one here and the other in the Discussion-mounts section. Both threads are now merged in to a single thread and cleaned up a little. ie threads merged.

Ohhhh my bad, i thought u meant something threaded like worm wheel or so, okok ye i did it because i thought i posted that on a dead part of the forum so i wouldnt get answers so quickly, thanks for the info, however any ideas abt my issue?😅😢

6 minutes ago, Cornelius Varley said:

Threads merged.

Hi, could you explain better? Im not very handy with goto mounts i never had one before so i don't get what you mean with this

Um, look this mount only tracks if you lock both axis, that's how it's supposed to be, so i don't really believe it's fine if theres the lock switch on and it still wobbles 

Hi, i would like to know if somebody knows if i have an issue in the meshing or somewhere else, i never owned any mount like this so i have no experience at all, i started to notice this wobble just yesterday however it happens only if i wanna turn the mount on the left. Please let me know how i can or if i can fix this, i need to sort it out well because i have an RC on it