HEQ5 - Polarscope alignment - HELP!

[Dante]

I have attempting to align the polarscope on my mount with no success.

I have been following the excellent guidance published by Astrobaby.

I have tried in daylight, in the house and tonight in the dark.

I can't see anything except the ret and that's not too clear.

I pointed the scope at v.bright lights about a mile away, certainly brighter than any star but I can't see them in the scope.

Am I missing something or, not doing something.

I do need your help:icon_scratch:

Danny

[Earl]

does this help?

[Earl]

Also

CG-5 Easy polar alignment using the polar scope

[samtheeagle]

Have you extended the counter weight bar and rotated the dec axis so that the hole in it is lined up correctly? I always forget to do that bit myself when setting up, and then the penny drops!

[Dante]

Hi All

Laptop battery ran out last night so couldn't respond.

I shall look at the websites suggested

Sam - I didn't extend the weight rod but i will go now and have a look in daylight again. It never ocurred to me to extend the rod. What a wally:rolleyes:

Danny

[samtheeagle]

Heh heh, don't worry about it, I forget to do that pretty much everytime I trying to polar align! Maybe I'll get the hang of it one of these days

[Breakintheclouds]

I don't want to admit how often I've stood in the garden, shuffling my tripod around completely unable to find Polaris, before realizing I've not rotated the dec axis...

[Dante]

Hi All

Been downstairs and tried again.

Low and behold dropped the weight rod rotated the axis to reveal the hole through which the polarscope views

Now that's sorted. One more question. The grub screws that hold the reticule. Are they metric? The smallest I have is 1/16 hex and it doesn't fit.

Danny

[IanC11]

The grub screws that hold the reticule are 1.5mm, so yes they are metric.

Ian

[Breakintheclouds]

My HEQ5 came with a 1.5mm allen key, so might be worth checking?

[Dante]

Hi All

No Allen key with the ,ount but I've bought a set of Metrics. Glad to say I've aligned the polarscope to the mount next is to align it all with Polaris (if I ever see it again )

Danny

[Psychobilly]

My EQ3 pro came with the wrong size allen key...

Peter...

[great_bear]

Glad to say I've aligned the polarscope to the mount next is to align it all with Polaris (if I ever see it again )

See also my post <here>

[Dante]

Hi great_bear

Printed your other post and I will check what I have done. Your remark re the date ring puzzled me but it also highlighted my particular Date Ring. It's not just floppy but it easy to turn by touching it. If it doesn't matter why is it there in the first place.

re: It's actually fun - well what can I say? Maybe have my prescription changed

[Astro_Baby]

You can adjust the tension on the date ring. Remove the polar scope and there is a series of collars on the back held on by set screws. These can be lossened and the collar holding the date ring tightened.

You cal also adjust the focus of the main polar scope tube by loosenning the set screws and rotating the polar scope tube. Its a bit hard to explain without pics but easy to see when you take the polar scope out.

Mel

[great_bear]

If it doesn't matter why is it there in the first place.

Yeah it's really mind-boggling initially, until you "get it".

It's hard to explain, but I'll give it a try:

The white mark on the Index Ring (once locked with the set-screw) provides the Polar Scope with a fixed reference point. This is important.

Now, every 24 hours, the earth rotates once on its axis

If that statement were 100% accurate, then since the RA ring is divided up into 24 hours, all you'd need to do is align the index mark with the current time, and the reticule would always show the correct position for Polaris

Unfortunately, that statement not 100% accurate Every day that goes by adds about 4 minutes onto our rotation, because our daily reference point is the Sun (which we're orbiting) rather than the background stars, which are fixed (relatively-speaking)

Therefore, for every day "into" the year we currently are (at today's date), we need to subtract 4 minutes (approx).

So by using the Date Ring as an intermediate reference point between the current GMT time on the R.A. Ring (midnight at top) and that white mark on the Index Ring, we're subtracting 4mins x "number-of-days-into-the-year" from the current time. Kind of like a slide-rule.

In addition the meridian marks will offset the result by the correct number of minutes for your location - so that you're dealing with the genuine time-of-day where you are, rather than the official time-of-day.

The alignment procedure that I outlined in the other post, just guarantees that the white line on the Index Ring is in the right place for this all to work properly.

It's pretty neat really.

Quite beautiful in it's own simple way.

[great_bear]

my particular Date Ring. It's not just floppy but it easy to turn by touching it. If it doesn't matter why is it there in the first place.

I may have misunderstood your post (above) when I first read it. Anyway - just to be clear - I meant that the lack of precision doesn't matter; not that the Date Ring itself "doesn't matter" (I've now updated the original post in the other thread in order to make that clearer)

If I've left anything else unclear, let me know...