Re: #Keypad Park Positions: AP 1100 GTO with encoders #Keypad


Roland Christen
 

Using your keypad only (no other program attached to the mount) I would test the parks this way:

1) level the mount as best you can. It does not need to be perfect
2) send the mount to Park3 and adjust the RA and Dec axes manually so that the reference marks on the side of the axes line up
3) send the mount to Park2. The DEC will swing 90 degrees to point due East. See if the Dec axis reference marks line up. The RA axis will stay where it was in Park3.
4) send the mount to Park5. The RA should swing exactly 90 degrees until the reference marks on RA line up. The Dec axis will point the scope to the northern horizon. If it points low or high, adjust the altitude axis until the scope is level.

Forget about Park4, I never use it because it puts the scope in an awkward position where the camera is towards the north end and it tends to stretch out my camera cables.
Forget about Park 1, it is an obsolete park position that is at the cwt up position and is not useful any more (even though it was once our preferred starting position).

Parks 2, 3 and 5 are the only really important ones for daytime polar alignment. They have no other purpose really, except that they can be used to recover a mount after being lost due to an errant sync or recal. You can use them for initial setup if you are always tearing down the mount after each use, but have no function for a permanent setup. You NEVER have to park the mount at any of these park positions when you are finished with a session unless one of them happens to be convenient. You can pull the plug at any point and wherever the scope happens to be pointed and the CP4 servo will remember exactly where it is the next time you apply power, unless you loosen the clutches and move the axes manually.

If you have any questions about your 3 park positions, run thru the above 4 steps and send me a quick picture of the exact position where your mount ends up in each of these 3 parks. From that I will have a much better idea of what is happening with your rig.

Rolando

-----Original Message-----
From: Thomas Giannaccini <tgiann3@...>
To: main@ap-gto.groups.io
Sent: Tue, Sep 21, 2021 7:37 pm
Subject: Re: [ap-gto] #Keypad Park Positions: AP 1100 GTO with encoders

Hi Roland,
I used the GPS coordinates from the compass app on my iPhone for where I was standing right next to the mount. I'm somewhat tech savy but not immune to  the learning curve. As a related disclaimer, I am able to get the pier somewhat level but not completely level due to landscape features. I am able to polar align the scope using the RAPAS. I did realize that I had set the time zone and daylight savings settings incorrectly early on but have long since fixed that. I do check time and location each time I start the mount up. The mount only moves about 20 to 30 ft between uses (from inside a tarp shed to outside the shed). Sometimes I even leave it in place overnight if the forecast is dry and I'll be using it the next night. I've used the mount approximately 8-10 times and the keypad seems fairly intuitive at this point but I do verify that I am not making mistakes.

As per George, an issue I was having early on was that I was hitting a limit. I had been starting at Park 1. The issue was resolved by slewing to Park 3 then manually adjusting the scope to Park 3. Generally, from Park 3 I can attain Park 1. Generally, I cannot attain both Park 4 and Park 1 simultaneously. When I try to attain Park 4 by slewing to it then manually adjusting, it throws the other Park positions off. Park 2 has been hit and miss depending on the sequence prior to an attempt to reach it. I cannot tell if I am hitting other limits somehow. A good question to ask now is when the mount is in Park 1 and slews to Park 4 which way is the main objective of the OTA supposed to swing? South or North? 

It seems as though polar aligning then starting at Park 3 and just moving forward is the easiest and most reliable process.

George did mention that it would probably be easier to run the mount from my PC, so I am deciphering that process now. I have already downloaded the drivers and such from the AP support page. I will be using Prism to run the mount which is ASCOM compliant.  In terms of hardware connections, I will be using an ethernet cable directly from my PC to the CP4 ethernet port.

Thank you for your help,

Tom

On Tue, Sep 21, 2021 at 5:51 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
All this only works if the latitude location data is correct. If the keypad is set for Miami and the mount is in Montana, then this will cause the park positions to be wrong.

Rolando

-----Original Message-----
From: Mike Dodd <mike@...>
To: main@ap-gto.groups.io
Sent: Tue, Sep 21, 2021 6:43 pm
Subject: Re: [ap-gto] #Keypad Park Positions: AP 1100 GTO with encoders

On 9/21/2021 6:57 PM, Thomas Giannaccini wrote:
> After speaking with George (who was very helpful) I have come to realize
> that Park 3 is the position which is central to all else. One would
> think that once Park 3 is re-established that Park 1,2 and 4 would then
> be attainable

Park 1 used to be the "reference" position, but now Park 4 or 5 is
recommended instead. Loosen the clutches and command the mount with the
keypad or ASCOM driver to park in Park 4 or Park 5.

Next, loosen the clutches and physically make the counterweight shaft
and the OTA level. Once you do this, unpark the scope from "last parked."

If the mount has your date/time and your local coordinates, you should
be able to slew to a target with good accuracy.

> I spent several sessions with the mount where I thought that because I
> was unable to achieve all (1-4) Park positions, that I would not be able
> to find my targets.

I use a machinist's level accurate to 20 arcsec to level my 1200's CW
shaft and OTA in Park 1(I'll use Park 4 next time), and when I unpark
and slew to a target, it's within the central 50% of my camera's sensor.

I don't think one Park position is related to any other one. They ARE
related to coordinates and date/time.

--- Mike







--
Roland Christen
Astro-Physics

--
CN: HasAnyoneSeenMyNeblua

--
Roland Christen
Astro-Physics

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