Restoring Home Position

[JSeaman]

I had a small hiccup last night whereby my smart plug pulled power before the 'scope was parked. I've had to deal with this a few times for various reasons and, rather than spend an hour setting it back up each time, is there a way of restoring the home position a bit more scientifically than pushing the scope around unti l have the star in the middle? It feels like I should be able to store encoder positions in the home location or similar, any thoughts?

Thanks

James

[newbie alert]

6 hours ago, JSeaman said:

I had a small hiccup last night whereby my smart plug pulled power before the 'scope was parked. I've had to deal with this a few times for various reasons and, rather than spend an hour setting it back up each time, is there a way of restoring the home position a bit more scientifically than pushing the scope around unti l have the star in the middle? It feels like I should be able to store encoder positions in the home location or similar, any thoughts?

Thanks

James

Hi James , Are you talking about your star alignment being lost because of the loss of power? Or have you lost your home position because of it?

Edited January 16, 2020 by newbie alert
Added info

[JSeaman]

I'm not sure quite what you mean by star alignment? 

When I next power up, it will assume it's in the home position and is pointing towards IC401 at 1:30am! I normally just manually put it back to roughly correct and spend ages chasing my tail trying to hone in on a star. Once that's done I'm all back to normal but it's a painful exercise I'd like to avoid

[Merlin66]

No,  it should assume you're at the "Home" position - pointed to the pole counterweight down.

Set the scope to this position - unpark and you should be good to go.

 

[JSeaman]

That's the problem, it isn't just a case of point it at the pole, it takes a long time for the atik 314l to be pinned accurately enough at a star. I was hoping there would be a method of reading the encoder positions or similar to accurately position the scope

[old_eyes]

If you are imaging, can't you just platesolve to work out where you are and then synchronise to that location? It has revolutionised my astronomical workflow. If I have the problem you describe for any reason, I just get the scope back roughly to home (counterweight down, pointing at pole ), and I mean roughly. Slew to target, take an image, platesolve, sync and then centre target. So far it has worked every time for me.

[Merlin66]

Question:

Are you using EQMod or the Synscan hand controller??

 

[JSeaman]

Yes indeed, I could plate solve, simple and effective thanks!

 

I'm using EQMod 

[newbie alert]

19 hours ago, JSeaman said:

I'm not sure quite what you mean by star alignment? 

When I next power up, it will assume it's in the home position and is pointing towards IC401 at 1:30am! I normally just manually put it back to roughly correct and spend ages chasing my tail trying to hone in on a star. Once that's done I'm all back to normal but it's a painful exercise I'd like to avoid

I'm even more lost now..

What mount are you using, home position is counter weights down and both index marks aligned and pointing at the north celestial pole,  if you're northern hemisphere....

 

[newbie alert]

13 hours ago, JSeaman said:

That's the problem, it isn't just a case of point it at the pole, it takes a long time for the atik 314l to be pinned accurately enough at a star. I was hoping there would be a method of reading the encoder positions or similar to accurately position the scope

Polar alignment shouldn't be pointing at any star..should be at the ncp ..this should be done first

For star alignment this is for your accurate goto's

Plate solving will do the same thing

[JSeaman]

I must have made it sound more complicated than it is

 

This is an NEQ6 Pro running EQMod

Normally you park then power down

I pulled power accidentally while it was pointing at a target

 

Now I have to set the home position back to zero (very easy to do roughly) and spent ages trying to get it preceisely aligned so the Atik 314L on my ED80 sees a star, the smallest misalignment means no star

[newbie alert]

Seems to me you have lost your pointing of the star alignment..From your home/start position you need to tell the mount where the star actually is rather than where the mount thinks it should be from your latitude and longitude.. 

I don't use eqmod personally but this is how I do things from scratch.. I polar align, then I star align..take it you're using Artemis capture if you have a Atik?   I set the camera looping , goto the first star in the star alignment routine,  center it in the finder and then center it in the bullseye on the screen..do this for all your alignment stars, it maybe a 1 star alignment or a 2 star with calibration stars..

Or if you have a platesolve software then just platesolve, sync and save..I choose to have my star alignment saved in the mount so I can hibernate and wake up next time around and no need to re-do the star alignment process

[JSeaman]

Sorry the point is obviously still not clear, I know how to set my home position and this has no effect on n-star alignment. The issue is that the FOV is small on the Atik so finding a star is a PITA, plate solving will help with this

Oh and I'm not using Artemis, it's Nebulosity

[Davey-T]

No idea about NEQ6 but when I muck up parking my Meade mount I simply turn it on select park and it wanders off to where it thinks park position is I then loosen the clutches and put it in park position ( up south ) and carry on as normal, do a one star sync using the finder if necessary then centre it I'm using the Atik 314 at 2500mm focal length and the GoTo generally gets the target on the sensor.

Dave

[newbie alert]

55 minutes ago, JSeaman said:

Sorry the point is obviously still not clear, I know how to set my home position and this has no effect on n-star alignment. The issue is that the FOV is small on the Atik so finding a star is a PITA, plate solving will help with this

Oh and I'm not using Artemis, it's Nebulosity

Having a well aligned finder helps..if I put the star in the cross hairs of the finder it's pretty much in the center of the imaging camera.. I've used the 285 sensor..it's not that hard unless you're using some large fl scope

[JSeaman]

If you keep going on about finderscopes I might have to put one back on

[JSeaman]

Oh and I assure you it's pretty damned hard to get the star in the centre!

[JSeaman]

Well that was a disaster, I got "all sky plate solver" working and it was the biggest mistake I've ever made. 

I don't see a way in CDC of syncing to an RA/DEC (you can view it though), I only seem to be able to synch to a target. Even if I could I don't think this will actually do what I need as it synchs one point but the home position is still wrong.

I got it to talk to the mount and it said it had synched with Betelgeuse (verified by it's own plate solving) despite the star being visibly nowhere near

I also found that it screws with all things ASCOM, it killed Nebulosity twice, made my Atik filter wheel get stuck between filters and has caused me 3 hours of trouble for nothing. I've never had any issues like this until tonight and it's going to take me another night at least to sort out. What a bad call that was. 

I'll go back to spending an hour moving the mount around until I find a star next time

[michael8554]

If I've correctly entered your ED80 and 314L correctly into my planetarium, then the moon fits nicely in your FOV ??

You ought to be able to "find" the moon by initially sighting along the OTA, then hand panning to find and centre it on the camera display.

Then Synch.

Now I assume it should then return to the home position when you request it ?

If not I guess you will have to switch on in the Home position, slew with the handset to the moon as above, and Synch.

I can understand that finding stars to Synch on can be tricky with a smallish chip, which is why an accurately aligned finder is essential to get you close IMO.

For example, the three stars of Orion's Belt should be obvious in a finder, you can then centre on say Alnitak, confirm on the camera, and Synch.

Michael

[Merlin66]

What plate solver did you use?

I use a C11 @f10 on the NEQ6pro with EQMod.

I also have a 60/ 220 eFinder (using a DMK51). I can plate solve the eFinder field to confirm centring of the target . I only do spectroscopy.

 

 

[Paul M]

Sooo, can you not pop an eyepiece in, sync to a known object(s) visually, check the GoTo quality. Ok? Then tell the mount to park. Will it not then take it self to Due South on the RA axis and 90 deg Declination? From there it's business as usual?

That's how I'd set Home, if I used home, which I don't for my non permanently sited, visual use only NEQ6.

[newbie alert]

8 hours ago, JSeaman said:

Oh and I assure you it's pretty damned hard to get the star in the centre!

Why is it so difficult.. what scope are you using with the atik?

[JSeaman]

Michael - I think the home position has to be set with the clutches, I'm not sure synching works. I agree with your approach and that's what I normally do, I just wanted a more scientific/repeatable approach, I took a big step backwards!

Merlin66 - It was "all sky plate solver"

Paul - I'm trying to avoid eyepieces, I want to leave the camera/focusser/filter wheel attached at all times

Scope is an ED80 per my sig

Last night was a bad night, tonight if I get a chance I'll just do things like I did before and ditch the plate solving

[michael8554]

I have a Meade so don't understand the subtleties of setting up an EQ mount. 

But I think the mount will have lost all knowledge of where it was when you got the premature power down. 

So IMO you can only return the mount to the Home Position, switch on, Synch on the moon, then a star near your target, then Goto your target and start maging!

Michael 

[JSeaman]

Yes exactly that.

I just finished taking the Atik EFW apart and found a defect in the metal ring which holds the O ring so that now runs freely again, I guess that was just coincidence as it was obviously a manufacturing fault.

I've rebalanced everything and set it to the home position by eye and will try and align on a star tonight if I get a chance