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ASIAir - Home Position

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#1 Liquidtravel

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Posted 23 September 2022 - 01:11 PM

Now that I have my scope all set up, I am trying to figure out the best way to set it up outside to make sure everything works as intended.  Out of the box, where does "Go To Home" go to?  I have only read one report that suggests it will point to Polaris.  If correct, that would mean when I set up the tripod, mount, scope, etc., I need to have it pointing at Polaris correct?  

 

Is the above true?  Is so, how to you ensure it is as accurate starting out as possible and what if Polaris is not available based on obstructions or too faint to see?  Normally, I have a pretty good line of sight to Polaris but some times, it is too faint to see.

 

Or

 

I place the rig and then let it plate solve wherever it is pointing and then it knows where Polaris is and the "Go To Home" just points there.  

 

thanks

 

 



#2 dave85374

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Posted 23 September 2022 - 01:53 PM

I set my AAP up just like my telescope.  The telescope is set up level and pointing north.  When I start the scope, I do a one star alignment, then I put on the Baht Mask to get a good focus, then I turn on the AAP and slew to someplace and let the AAP plate solve the location.  That procedure has worked now for 16 months.



#3 SkyHunter1

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Posted 23 September 2022 - 01:54 PM

I use the AIR on my rig. In my case with the CEM60, the hand controller has an search home option and it finds home for me. That's the only thing i use the handset for. Once I have the scope in home position the use of the handset ends. 

 

At that point I turn on the AIR. The air will consider ANY position the scope is in as home when its turned on. so if your mount is in a weird position when you turn the AIR on, that's where the air will move your mount go when you "go to home". This has been confirmed by other air users as well that I've imaged with.

 

I polar align using a polemaster and use the air to move the mount. You don't need it pointing to Polaris. The home position has nothing to do with polaris at all, just that the mount is in the home position. 

 

The process:

 

Either use the handset to find home, or home the mount manually using the numbered dials on the mount which most mounts have.

 

I use my phone and sky guide to orient the mount towards polaris so I don't have to move it later. I place the phone vertically on the mount saddle and point it towards polaris and get it in the center of the phone using the app by physically moving the entire setup, tripod and all.  This always gets polaris in the view of the polemaster camera when I'm ready to align after dark. DO NOT move the mount from home position during any of this process. 

 

Turn on the air. The air will take this position as home.

 

polar align using whatever method you use using the mount bolts etc as usual. 

 

I get .2 - .5 RMS guiding most nights.

 

I don't know what method you use to polar align, but the above is a guideline of how its done. 

 

Home is unrelated to polaris. Even if polaris wasn't in the FOV I could move the entire setup slightly to get it in view. the key is to have the mount in the Home position at all times. then begin your PA using whatever method you use. the air will go to the position (home) you had it in then you turned the air on. After your PA, then "go to home" using the air, and then do your star align (3 stars minimum)

 

Hope this helps smile.gif

 

Regards,

Skyhunter1


Edited by SkyHunter1, 23 September 2022 - 02:05 PM.


#4 c131frdave

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Posted 23 September 2022 - 01:55 PM

You have a unique setup in that you have an ASI mount.  Home should be straight parallel with the earth's axis.  I would imagine with your mount, just hit home and it will go home.  That mount doesn't have clutches, so you can't just move it where you want by hand.  I would suggest turning on AA plus and seeing what it does.  It will probably take care of all that on its own.



#5 Liquidtravel

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Posted 23 September 2022 - 02:29 PM

Yeah, since I am using the AM5 mount, I have to use the ASIAir Plus.  I took the mount out of the box, placed the scope on it with the AA+ and it was point up.  I turned everything on just to check it all worked, slewed the scope a couple of time, made it go back to "home" which took it back to the position it was in, then turned it off.  This was all done inside my house.  I have done that twice now.  

 

I am assuming that if I took it outside in this position, and pointed it north, it would be pretty close to polaris.  Not sure yet.  



#6 Liquidtravel

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Posted 23 September 2022 - 02:43 PM

 

 

Home is unrelated to polaris. Even if polaris wasn't in the FOV I could move the entire setup slightly to get it in view. the key is to have the mount in the Home position at all times. then begin your PA using whatever method you use. the air will go to the position (home) you had it in then you turned the air on. After your PA, then "go to home" using the air, and then do your star align (3 stars minimum)

 

Hope this helps smile.gif

 

Regards,

Skyhunter1

So, you are saying that "Go To Home" is just a resting point.  It is not really pointing anywhere specific?  I don't have a hand controller so I have to use AA+ as soon as I turn everything on.



#7 kathyastro

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Posted 23 September 2022 - 02:45 PM

"Home" is a mount function, not a software function.  The ASIAir will just issue an instruction to the mount to "go to Home" (wherever that is), and the mount goes to wherever its home position is.

 

Most mounts are set up so that the Home position is, as you said, pointing at the celestial pole.  (Not to be confused with the Park position, though many mounts default their Park position to be the same as the Home position.)  Home is the starting point for a goto alignment.

 

To set an accurate Home position, swing the mount so that the counterweight arm is horizontal.  Measure that it truly is horizontal using a level.  Set the setting circle (hopefully you have one) to 0 hours.  Now swing in RA so that the counterweight is down.  Use the setting circle to ensure that it is exactly 90 degrees (6 hours) from the horizontal position.  This is the RA component of Home.

 

With the RA axis locked in the Home position, swing the scope so that it is horizontal.  Again, measure that it is horizontal using a level.  Note the reading on the Dec setting circle.  Swing the scope in Dec until it is pointing at the pole.  Use the setting circle to ensure that it is exactly 90 degrees from the horizontal position.  This is the Dec component of Home.

 

The mount is now in an accurate home position.


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#8 unimatrix0

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Posted 23 September 2022 - 03:02 PM

So, you are saying that "Go To Home" is just a resting point.  It is not really pointing anywhere specific?  I don't have a hand controller so I have to use AA+ as soon as I turn everything on.

Easy way to sum it up, the Home position will be the position how your mount was (in RA and DEc) before you turned on your system.  For about 99% of the people, this is the position where the mount weights are down, scope is pointing straight ahead. 

If it would be polar aligned, it would be looking at Polaris. 

 

Other people may have other "home position". Maybe they have a dome and the scope needs to point to a specific location so they can close the dome above it. Maybe it slightly turned left or right in the DEC axis. Stuff like that. 


Edited by unimatrix0, 23 September 2022 - 03:03 PM.


#9 kathyastro

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Posted 23 September 2022 - 03:35 PM

Easy way to sum it up, the Home position will be the position how your mount was (in RA and DEc) before you turned on your system.  For about 99% of the people, this is the position where the mount weights are down, scope is pointing straight ahead. 

If it would be polar aligned, it would be looking at Polaris. 

 

Other people may have other "home position". Maybe they have a dome and the scope needs to point to a specific location so they can close the dome above it. Maybe it slightly turned left or right in the DEC axis. Stuff like that. 

That is the Park position, not the Home position.  They may or may not be the same.  Home position is the starting reference for a goto alignment.



#10 hyiger

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Posted 23 September 2022 - 04:39 PM

"Home" is a mount function, not a software function.  The ASIAir will just issue an instruction to the mount to "go to Home" (wherever that is), and the mount goes to wherever its home position is.

 

Most mounts are set up so that the Home position is, as you said, pointing at the celestial pole.  (Not to be confused with the Park position, though many mounts default their Park position to be the same as the Home position.)  Home is the starting point for a goto alignment.

 

To set an accurate Home position, swing the mount so that the counterweight arm is horizontal.  Measure that it truly is horizontal using a level.  Set the setting circle (hopefully you have one) to 0 hours.  Now swing in RA so that the counterweight is down.  Use the setting circle to ensure that it is exactly 90 degrees (6 hours) from the horizontal position.  This is the RA component of Home.

 

With the RA axis locked in the Home position, swing the scope so that it is horizontal.  Again, measure that it is horizontal using a level.  Note the reading on the Dec setting circle.  Swing the scope in Dec until it is pointing at the pole.  Use the setting circle to ensure that it is exactly 90 degrees from the horizontal position.  This is the Dec component of Home.

 

The mount is now in an accurate home position.

He has an AM5, there are no clutches, nor setting circles nor (usually) a counterweight arm. 



#11 Liquidtravel

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Posted 23 September 2022 - 04:45 PM

"Home" is a mount function, not a software function.  The ASIAir will just issue an instruction to the mount to "go to Home" (wherever that is), and the mount goes to wherever its home position is.

 

Most mounts are set up so that the Home position is, as you said, pointing at the celestial pole.  (Not to be confused with the Park position, though many mounts default their Park position to be the same as the Home position.)  Home is the starting point for a goto alignment.

 

To set an accurate Home position, swing the mount so that the counterweight arm is horizontal.  Measure that it truly is horizontal using a level.  Set the setting circle (hopefully you have one) to 0 hours.  Now swing in RA so that the counterweight is down.  Use the setting circle to ensure that it is exactly 90 degrees (6 hours) from the horizontal position.  This is the RA component of Home.

 

With the RA axis locked in the Home position, swing the scope so that it is horizontal.  Again, measure that it is horizontal using a level.  Note the reading on the Dec setting circle.  Swing the scope in Dec until it is pointing at the pole.  Use the setting circle to ensure that it is exactly 90 degrees from the horizontal position.  This is the Dec component of Home.

 

The mount is now in an accurate home position.

thanks but my mount is a harmonic drive mount and does not need a counter weight.  This is the ZWO AM5 mount. 



#12 kathyastro

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Posted 23 September 2022 - 04:50 PM

thanks but my mount is a harmonic drive mount and does not need a counter weight.  This is the ZWO AM5 mount. 

OK.  But the principle is sound: you need to measure the position relative to the Earth's surface to get an accurate Home position.  If you have accurately levelled the mount, you can take measurements from it.  What you measure and how is up to you.



#13 Liquidtravel

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Posted 23 September 2022 - 05:16 PM

OK.  But the principle is sound: you need to measure the position relative to the Earth's surface to get an accurate Home position.  If you have accurately levelled the mount, you can take measurements from it.  What you measure and how is up to you.

OK, it may be sound but it is not practical for the mount I have.  I appreciate your thoughts but I was hoping someone with an AM5 might jump in to answer where it is supposedly pointing out of the box and whether or not it was Polaris and if so, do I need to set it up to point at Polaris each time I set it up.  That is the real question.  

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Edited by Liquidtravel, 23 September 2022 - 05:18 PM.


#14 kathyastro

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Posted 24 September 2022 - 05:54 PM

OK, it may be sound but it is not practical for the mount I have.  I appreciate your thoughts but I was hoping someone with an AM5 might jump in to answer where it is supposedly pointing out of the box and whether or not it was Polaris and if so, do I need to set it up to point at Polaris each time I set it up.  That is the real question.  

You are going to have to read the device's manual for that.  If it has absolute encoders, you don't need to do anything except polar align it.  If it doesn't have absolute encoders, then you literally have to tell it which way is up, because it has no way to tell.  That's what setting it in the home position is for: telling it which way is up.  So, yes, you will likely have to point it at Polaris every time.



#15 unimatrix0

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Posted 24 September 2022 - 06:06 PM

You can also try to contact someone with the same mount in the Mount- sub forum. 

 

This thread is all about the AM5 and a couple of people have the gear. 

https://www.cloudyni...e-mount/page-70



#16 Liquidtravel

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Posted 24 September 2022 - 08:11 PM

You can also try to contact someone with the same mount in the Mount- sub forum. 

 

This thread is all about the AM5 and a couple of people have the gear. 

https://www.cloudyni...e-mount/page-70

thank you.




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