EQ6 polar alignment woes

[palebluedot]

Hi again SGL,

I had a frustrating evening last night trying to polar align my new EQ6 for the first time. I spent so long squatting to look through the polar scope trying to find Polaris that it flared up an old knee problem and have been struggling today. Anyway, I was wondering if someone could give me a rough altitude setting for a level mount in the south of England so that I can at least be in the right half of the ball park this evening.

Looks like I could be a good one here

[palebluedot]

Scratch that. I have just discovered the latitude scale

[Skylook123]

My latitude scale is about five degrees off. I have to use an inclinometer (sort of a large protractor for making sure walls and shelving are level) to set the latitude. It cost me about seven dollars US at a builder's supply store. Try to learn the latitude of the location, then use the information to first level the tripod and add the mount head, then set the angle of the the dovetail slot with the inclinometer. To get Polaris into the scope does require leveling prior to the latitude angle set.

If you are within a few degrees of correct, I find it easier to do an iterative star alignment. Easier to do than describe. First, level the tripod and mount, and try to get it as close to 0 degrees azimuth with a compass, and elevation set with the inclinometer. Then, do a 1 star alignment followed by a GOTO Polaris. When the mount returns to Polaris, it will likely be some distance off. Take out HALF of the the difference with the mount's azimuth and latitude adjustments. Redo the one-star alignment, and again GOTO Polaris. Should be much closer. Again, take out half of the offset mechanically. If it seems like you are close enough to get Polaris in the polar scope, finish the task with the polar scope. The reason to only take out half of the offset at a time is that it is possible to worsen the misalignment if you take out more, because of the way the math works. I set up at different schools five or six times a month, as far as 380 miles apart, and it only takes me six or seven minutes to get the polar alignment sorted.

Good Luck!

[ollypenrice]

The altitude setting is just your latitude which you can get from a map, GPS or the web.

(At the North Pole it would be 90 degrees, directly overhead, and at the equator it would be on the horizon, 0 degrees. I guess you'll be in the low fifties somewhere.)

A way to save your knees in all forms of aligning and quick finding (in my case it's my neck I have to save) is simply to shoot a green laser through your polar or finderscope. In your case it's the polarscope. The scope will direct the beam pretty accurately along its axis and show you where you are pointing. There will be howls from some about the evils of lasers but a little sense goes a long way. Don't fire them at aircraft.) This is a brilliant joint and time saver.

Have you checked that your polarscope is on axis? Arrange the mount in the daytime so that you can see a distant object in the polarscope. Rotate the RA axis and ensure that the central cross remains on the same spot. Use the three adjusting screws to correct it if it doesn't. Unless you are an imager, don't kill yourself to get it dead perfect.

Olly

[palebluedot]

Thanks guys. Olly I have checked axis of the polarscope, it didn't need adjusting thankfully. I love the laser pen idea, I happen to have one, I'll give it a shot tonight, and yes I will be sensible.

[Skylook123]

...A way to save your knees in all forms of aligning and quick finding (in my case it's my neck I have to save) is simply to shoot a green laser through your polar or finderscope. In your case it's the polarscope. The scope will direct the beam pretty accurately along its axis and show you where you are pointing. There will be howls from some about the evils of lasers but a little sense goes a long way. Don't fire them at aircraft.) This is a brilliant joint and time saver....

Olly

Gosh, Olly, where is the "fun" and feeling of triumph over adversity in that? Isn't wrecking one's back and knees a part of the admission price to setting up a GEM?

Great suggestion. I try not to bring out the laser pen too early at the elementary schools; the first time the students see it, you've lost them (the boys, anyway). But I could do without sitting on the ground doing polar, then wondering if my 64 year old knees will work one more time, and worrying if I'll topple the mount accidently when I stumble getting off the ground.

Thanks for the hint!