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mount "park position"?

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#1 KDizzle

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Posted 16 May 2011 - 09:41 PM

I've read bits and pieces about having mounts being "parked" when they are not being used. Usually this looks something like what you'd expect while you are trying to balance a scope. I ws wondering if anyone could explain what the reasoning is and/or what positions are better/worse for whatever reason? Does the OTA size make a difference in any way?

#2 M13 Observer

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Posted 16 May 2011 - 11:26 PM

I've read bits and pieces about having mounts being "parked" when they are not being used. Usually this looks something like what you'd expect while you are trying to balance a scope. I ws wondering if anyone could explain what the reasoning is and/or what positions are better/worse for whatever reason? Does the OTA size make a difference in any way?


Known park positions make setting up a portable outfit easier for one major reason. If you know the 'park' positions a mount has you can put it together and manually place it in that position. Then when you start it up, resume from park, and it will be in a known configuration and should point roughly where you want. Of course you will have to polar align and fine tune the alignment but it is far better than having to restart from who knows where.

#3 Mary B

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Posted 17 May 2011 - 12:07 AM

With an observatory the park position is used to clear the roof as it closes.

#4 JAT Observatory

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Posted 17 May 2011 - 02:18 AM

I have a domed obs so the configuration doesn't have an issue with roof clearance.

The park position I use for my mount points south and is just a few degrees below horizontal. I chose this position because it keeps the dust off of the aperture of OTAs (since they are not covered) and it allows the camera pigged backed on one of the OTAs to see the volt meters mounted on the dome.

Since I sometimes use the system remotely being able to see the meters allows me to confirm a few things. The 1st thing is the meters tell me if the shutter battery is fully charged before I start a session and if there will enough power for the rain sensor to auto close them if needed during the session. Also at the end of the session if I can see the meters, I know the scope and dome have been correctly parked. That confirms the solar panel on the outside is facing south and will see the maximum amount of sun during the day in order to keep the battery charged.
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#5 skybsd

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Posted 17 May 2011 - 03:41 AM

Hello,

I've read bits and pieces about having mounts being "parked" when they are not being used. Usually this looks something like what you'd expect while you are trying to balance a scope. I ws wondering if anyone could explain what the reasoning is and/or what positions are better/worse for whatever reason? Does the OTA size make a difference in any way?


Various computer-controlled, GoTo mounts provide a feature that allows the end-user to power off the mount in a pre-defined position setting in the mount's software that enables the mount to resume operation from that known position and retain pointing accuracy defined previously.

This allows the end-user to resume operations without needing to repeat mount alignment procedures each time they turn off their mount. This is the primary purpose of this feature.

Nearly all such mounts have a factory default defined position, which is commonly referred to as the "Park Position". For example, Losmandy GoTo mounts use the CWD (Counter Weight Down) position, whilst, Astro-Physics GTO mounts use the horizontal scope (as you mentioned in your initial post) position.

Many mounts allow the user to define their own, custom park positions to suit their own local requirements. As Marcus has suggested, folks with appropriately sized dome observatories do not generally need to use the scope horizontal position for clearance problems, whilst the majority of roll-of-roof observatory owners need to use the scope horizontal position in order to be able to close their rolling roof without hitting the scope.

Hope that makes sense, and that it helps..,

Regards,

skybsd

#6 jmiele

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Posted 17 May 2011 - 08:09 AM

The AP ASCOM driver allows for a "resume from last park" and "park at current". Additionally, there is a beta driver and the new APPC software that should be along soon that I believe has substantially improved OBS control protocols.

edit:
Ray Gralak (ASCOM) and the AP teams commitment, along with the current products like PEMPro are the only reason I still own Windows OS. I would be totally MAC at this point were it not for products like PEMPro.

I do run them mostly virtually at this point but they are Windows OS non the less. :)

Joe

#7 Phil Sherman

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Posted 17 May 2011 - 10:11 AM

Another reason to park amount is that (Synta) stepper motor driver mounts always base their motor position using the power on position as 0. If you're using PEC; you need to align the PEC data with the worm gear position and parking the mount before powering it off will always have the worm starting from the same position.

If your mount uses something other than a count of the number of steps to figure out where it's pointing; then parking to a known position may not be necessary to resynchronize the PEC data with the worm position.

Phil

#8 mtibor

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Posted 20 May 2011 - 07:23 AM

The "parked" feature is a very nice one.I only use my scopes for imaging.Having 2 rigs, setup time takes some time,since I don't have permament place for my scopes.When I setup my scopes in my backyard I always check the weather forecast for the next few days or so.If the weather is going to be clear I usually leave both of my rigs outside sometimes 4-5 days.When I do that I "park" both mounts.The next day all I have to do is power up both of them and I'm ready to go!That saves me lots of time,because setting up 2 rigs takes a LOT of time,especially the lx200 on the wedge and the "polar-alignment"

The Atlas mount I always use the "park in home position"since I have the 10"Newt. on it.On the lx200 rig I use the "use current position"option.Basicly what it does it saves you time not having the mount re-aligned every night if,you have obeservatory or if you leave the mount/scope out for a few days....

Tibor,

#9 djallar

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Posted 20 May 2011 - 07:51 AM

On my CG5, I set the home position so the C6-R clears the roof of the observatory when I close it.

#10 KDizzle

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Posted 20 May 2011 - 10:45 AM

If the weather is going to be clear I usually leave both of my rigs outside sometimes 4-5 days.When I do that I "park" both mounts.The next day all I have to do is power up both of them and I'm ready to go!That saves me lots of time,because setting up 2 rigs takes a LOT of time


I have still not yet gotten up the courage to leave my rigs outside all day. I bought a big tarp thinking I would like to cover them but for some reason I haven't gotten over the mental block yet. Maybe this summer sometime. OTOH, twilight is so extended right now that even though setup takes awhile I can see enough stars to get things aligned properly before my imaging session can start.

I was really concerned that "while resting in the garage" there was some special position the mount should be left (i never take the ota off) to increase mount longevity or something to that effect. Sounds like that's not the case but that it is something for convenience instead. Thanks for all the answers and input!

#11 skybsd

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Posted 20 May 2011 - 11:19 AM

Hello,

If the weather is going to be clear I usually leave both of my rigs outside sometimes 4-5 days.When I do that I "park" both mounts.The next day all I have to do is power up both of them and I'm ready to go!That saves me lots of time,because setting up 2 rigs takes a LOT of time


I was really concerned that "while resting in the garage" there was some special position the mount should be left (i never take the ota off) to increase mount longevity or something to that effect. Sounds like that's not the case but that it is something for convenience instead. Thanks for all the answers and input!


As long as your mount is balanced, it doesn't matter mechanically what orientation it is parked in.

Though for practicalities of storage, or clearance, you may wish to leave it in a particular orientation based on your needs in its storage space.

Regards,

skybsd






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