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Levelling the mount


The Warthog
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I left my scope out last night, covered, as it wasn't going to rain (and didn't) and today I decided to level it up properly. I started by putting an ep tube on the accessory tray to see which way it rolled, and adjusting legs to reduce the roll. After a while, I said to myself, "Gee, I wish this thing had a ... bubble level," just as I spotted the bubble level located on the west side of the mount.

I had a little trouble with my RA and Dec readings last night. I had polar aligned the scope after using a mark on the west side of the mount to line up at 90 degrees. When I rechecked the alignment a little later, using the nice chromed pointer, I was about 10 degrees off. Does anyone know that mark I am referring to, and what it's for? I took a look today in broad daylight, and it is not anything but an arrow pointing at the scale.

Can I reliably use the RA and declination scales to find stuff in my soupy skies, after carefully polar aligning? I hope so, as I'm getting fed up with shooting in the dark, as I am doing a lot of the time.

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Ummm, isn't "shooting in the dark" the whole idea? :D

Not sure what the arrow would be for, unless you point it North, maybe. ? That said, the only reason a mount has to be level for polar aligning is if it's an alt/az and computer controlled. Goto or not, the computer gets soggy and hard to light if it doen't know its exact alignment and orientation. For manual setting circle navigation, the drift align method works fine, levelness notwithstanding.

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I find that bubble levels dont work for me when im setting up at night as holding a torch and messing with tripod legs at the same time is a pain. I just make sure all the legs are the same length and where i plonk the tripod is level ish. I dont have a polar scope so i dont get massivly acurate alignment but as the night goes on i nudge the tripod in the right direction and by the end of the session it's close enough that my motors leave the target in the eyepiece for as long as i like, although not necessarily in the center of the eyepiece.

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WH

I assume that your EQ3 is an undriven mount?. If so, there isn't much advantage in properly polar aligning your mount.

Don't know the EQ3 mount but there is usually one pointer for the Dec scale and one for the RA scale. The Dec scale does not need to to be set to 90 deg when you polar align.

Ive polar aligned my mount since it's a driven mount but I didn't set the Dec scale to 90 deg. Provided I initially set the Dec & RA scales to a known star and keep the RA drive running I can use the setting circles to find a new object. With an undriven mount you have to keep turning the mount back to the reference star each time you want to look at a new object.

I polar aligned the mount after I'd levelled the mount using a carpenter's spirit level. I then marked the position of the tripod legs on the deck using an indelible marker. Since I had to adjust a tripod leg to level the mount I also marked the extension of the leg with the same marker. Now when I set up the tripod I've only to place the tripod legs on the three marks and extend one of the tripod legs and the mount is level and polar aligned. With the RA motor running I can keep most objects centred for many minutes and in the FOV of a high mag. EP for a very long time.

MD

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