Advice Please

[SteveRob]

Hi all,

Because of the amount of time I have available caused by irregular working hours I'm wondering if anyone has any input into what I am thinking of doing to save a bit of time when I want setup my scope in the garden.

My idea is to use some small pavers, one at each corner of the tripod - levelled and with a drilled indent into the surface where the feet go, so that I can just erect the scope and not have to worry about declination, my main concern is how to set it up so that I don't have to polar align after the first time setup, is that possible?

I have a compass, spirit level etc, has anyone else done this, if so any useful tips/diagrams appreciated.

Thanks

Steve

[nephilim]

Unfortunatley u have to polar align every time you set up as Polaris moves across the sky.

Steve

[SteveRob]

Oh dear, forgot about that duh!! Its a while since I've done polar aligning as well which doesn't help lol.

I think the first bit is feasible its just getting my head around how to do it, ideally I would like a pier, but I think this could do until I get round to making one.

Thanks for reminding me.

Steve

[Stu]

Hi Steve

You are not being dumb, Polaris doesn't move which is why it is used as a reference!

What you are suggesting makes total sense. Three slabs laid level with each other and aligned north would work very well. Drill a suitable hole for each tripod leg and then polar align properly. Should be pretty much bang on each time provided you've kept the legs extended fully. Certainly good enough for visual, may need slight tweeks for imaging.

Stu

[SteveRob]

Hi Stu,

I'm glad you clarified that, I guess I ain't so dumb after all, must have been a senior moment lol.

I think my main problem is getting my head around the relationship between magnetic North (using the compass) and polar north, as far I understand - (I could be having another dumb senior moment here) - I would start off using magnetic North, use one leg of the tripod at the north point and measure/ triangulate for the position of the other 2 legs, then get the bases in position, levelled, set RA, polar align, then mark the the legs and then drill the locator holes, does that make sense or have I missed something?

Cheers

Steve

[wookie1965]

Another member on here has done what you are proposing as long as you polar align properly then mark your tripod legs you will be fine, Then each time you set up you will be polar aligned as Stu said.

[Stu]

I think that all sounds right. I would probably just mark a triangle out orientated correctly and decide where to place the slabs. I would expect that you will have some leeway to correct for the difference between magnetic and true north. Just get it all setup and polar aligned, then mark the leg positions, drill the holes and Bob's your uncle!

Not sure where you are doing this, but if on the lawn you can inset below grass level so you can still mow over them.

Stu

[cfpendock]

I have done exactly this and it works fine. I chose a fine day with a promise of a clear night, and in the late afternoon I dug three holes in the ground approximately where I knew my tripod feet normally rest. Each hole was about six inches square and about ten inches deep and I then filled each one with concrete to just below ground level. I then set up the scope on its tripod on the wet concrete, pushing the tripod feet slightly to make sure it was perfectly level, polar aligned the scope and checked everything was OK. Then I carefully lifted the scope away and left the concrete to set. After a few weeks the grass effectively covered the concrete "feet" - I could mow over them without problem, and they are now virtually invisible. To set up the scope now, I just position the tripod in the indents in the concrete. Before putting it away I use a hibernate mode (Celestron scope), and alignment is then normally spot on.

Of course, to do this, you do need reasonable weather with the promise of a clear evening to get everything aligned. We don't have that sort of weather any more here, so I'm glad I did last summer...But I thought about paving slabs, and I think that I am correct that this provides a better solution. Moreover, in very dry weather there is significant ground movement here, and the foundation effect of the ten inch deep holes should help to overcome this. Naturally, we have had no dry weather since last summer so I cannot confirm this potential benefit.

Chris

[Josh Wilson]

For not need to align the scope each time I'd suggest a pier and there is probably a setting or something on your scope that allows you to save the alignment. I had a mode on my ETX that did exactly that but the mechanical reliability of that scope forced me to have to align it every time I went out.

Josh

[SteveRob]

Hi All,

From the replies it sounds like its a go-er, I think the main thing in my mind was having a solid, level base to start with and one of the legs oriented to North, a bit of tape on that leg should help me when its dark.

Cheers Guys

Steve

[E621Keith]

I wouldn't bother with accurate polar alignment if you are only doing visual observing. You can polar align once and then lock the altitude adjustment on the mount. As long as you don't change the altitude adjustment, your altitude will be correct for your next observation session.

As for Azimuth adjustment, I'd just put the mount down and eye up Polaris. One or two degrees off isn't go to be a big problem for quick visual observing.

I'd only do accurate polar alignment with the polar scope if I know I'd be observing for several hours, using GOTO, or imaging. It's not worth the effort for grab and go.

[laser_jock99]

Unfortunatley u have to polar align every time you set up as Polaris moves across the sky.

Steve

Polaris moves- but the pole doesn't (well only over thousands of years). In theory the idea might work but placing the tripod EXACTLY back in the same each time is probably nigh on impossible.

Good luck.

Edit- Polaris moving around a non-moving pole.

[Stu]

Yes it does, so my comment wasn't totally correct. But my main point was that if you polar align correctly based on the right position at the time then you should be able to get the setup back fairly accurately if you keep things constant ie the legs fully extended, level base, feet positions controlled then I bet it will be pretty close. It will certainly cut down setup time quite dramatically I should think.

Stu

[nephilim]

Hi Steve

You are not being dumb, Polaris doesn't move which is why it is used as a reference!

What you are suggesting makes total sense. Three slabs laid level with each other and aligned north would work very well. Drill a suitable hole for each tripod leg and then polar align properly. Should be pretty much bang on each time provided you've kept the legs extended fully. Certainly good enough for visual, may need slight tweeks for imaging.

Stu

I meant that Polaris isnt magnetic north and it does move in a small circle ( I should have explained myself better)

[SteveRob]

Hi,

? for BigMakStutov - I noticed that you said in one of your posts (fully extended legs), I'm only 5' 9" soaking wet will it really matter if they are not fully extended, so long as its balanced properly. Is it a problem ?

I also had another idea for locating the legs, mark up each paver and drill out, and araldite a big nut in each one, giving a positive position every time.

Cheers

Steve

[cantab]

Mark the legs so that you can extend them to the same length each time and bob's your uncle.

[SteveRob]

Hi cantad,

I think I will lock down the legs with self tappers at a height I can cope with (being vertically challenged lol), there's enough moving bits on a scope and in the sky without having to worry about tripod legs as well. I'll get there in the end!!

Cheers

Steve

[cfpendock]

With mine, I set it up in the concrete with the legs down as far as they would go. But this is a CPC1100 tripod and quite big - probably they are all different. The important thing is that the legs are set (and marked if necessary) so that you are as comfortable as possible.

Chris

[Stu]

Hi Steve,

The main reason I said about extending the legs fully was so that they were all extended the same amount. As said a couple of post ago, if you mark the legs at a lower height then you should be able to get them into the same position each time which will achieve the same result and be able to reach the eyepiece still :-)

Cheers

Stu

[SteveRob]

Hi Stu,

Thanks for the reply, I will set the scope up in the house first and extend the legs equally as you say - at a height that will let me at least see through the finderscope - this will be the highest point and then will be good for me, can't do it outside it's snowing again lol Maddening this weather innit!!

Steve

[SteveRob]

Hi Guys,

Just an update, I did a bit more research and found - solar noon calendar for my latitude, so this should give me true north, it gives me the months / dates / times each day, the only problem now is there has been either no sun to align to lol or I have been at work.

I guess I will just keep at it.

Cheers

Steve

[SteveRob]

Hi Guys,

Thanks for all the help, I now have the slabs all setup, level and the tripod set to true north, just what I needed for a quick setup being so time limited, finally got there.

I just wish the clouds would go away,

Clear skies.

Cheers

Steve

[66mikeg]

Polaris does move but by using the reticle in the polar scope and the offset of Polaris at the time you set it you align with the celestial pole which doesn't move.

I think