HEQ5Pro mount levelling.

[cotterless45]

I' m used to a bubble level on the mount and checking before and after polar aligment. I'm visual, so it's not critical. However with the HEQ5pro, there are curved surfaces and no bubble. Currentlty I level the tripod usuing a spirit level and then attach the mount and ota.

Anyone managed to fix a bubble?

Nick.

[Cornelius Varley]

There is no reason to level an equatorial mount. The RA and DEC axis are both independant of the azimuth axis so having the tripod level or not doesn't affect tracking or alignment.

Peter

[iwatkins]

As Peter says.

But if you setup each time, like I do, then getting the tripod in the same place and level is a good way to get an almost repeatable position. If I'm careful setting up, my PA is usually spot on.

Way I do it is to leave tripod and mount bolted together and use a big bubble level on the eyepiece holder. Gets me close enough.

Cheers

Ian

[Tinker1947]

Whilst it doesn't have to be level, if your happier that way, there are spirit levels on the market with magnets on one side, i brought one from Screwfix......

http://www.screwfix.com/p/torpedo-level/35466

[Steve Ward]

Easiest way I've found is to rest a short level against the legs pressing the top of the level against the bottom of the sleeves that attach the legs to the mount.

Means you can leave mount attached to tripod.

Mount may not need levelling but I just find it an easier place to start alignment.

[cotterless45]

Many thanks,it's just out of habit to get as level as possible.

Nick.

[starguest]

There is no reason to level an equatorial mount. The RA and DEC axis are both independant of the azimuth axis so having the tripod level or not doesn't affect tracking or alignment.

Peter

Is this where I've been going wrong all this time, getting poor GOTO accuracy?

So, if tonight is clear, take the tripod out, set the legs the same length and plonk it down any old place, choose 2 stars and - 3 hours of dead centre bliss?

Let me run this past you.

Get a CD case, a pen-knife, a compass, a protractor and a bubble level.

Open the large pen-knife blade and use the protractor to roughly have your latitude, let's say 50deg. Find north with the compass and place the pen-knife centrally on the case pointing to north. Lift the case in one hand supporting it with your palm and fingers with the thumb steadying the knife. A wide Swiss Army or Leatherman will sit more easily. Use your other hand to place the bubble level on the case to check it's level. You maybe don't need the bubble or protractor, however.

Extend a finger of your free hand and just touch the knife blade tip.

Now tilt the CD case, left or right, forward or back. Blade tip not at fingertip.

The plane of the case no longer matches the plane of the earth/Earth and the 50deg angle doesn't point where it should.

[ollypenrice]

Let's be clear, the best PA routine on the market is Takahashi's and their tripods don't have adjustable legs and cannot be levelled.

Levelling the mount does two things.

1) it calibrates the polar scope reticle by setting it to vertical/horizontal and if that's the way it is designed to work it is best to respect that. If you are going to drift align don't bother. Put the time into drift aligning.

2) it reduces, by a very small amount, interaction between axes when drift aligning. This doesn't, in reality, add up to much.

It does nothing else and is not necessary in principle. Why does the universe care where your tripod legs are pointing?

Levelling legs takes a remarkably long time in my experience and the Tak system is finished and running by the time you've done it, so why don't more mount manufacturers wise up? Do Tak have patents? I'd be surprized.

Olly

[starguest]

Yes indeedy. Makes a change from the 'can't see stars' or 'can't focus' 'can't find my co-ordinates' texts. Maybe if my cleaned S.A. knife wasn't sitting there opened up to dry providing mischievious inspiration...

Perhaps just as seriously...

Imagine the production cost savings the manufacturers would be happy to pass on to you if on all their appropriate GEMs they:-

removed the bubble level,

omitted the declination markings,

removed refs to them in the manual text -all that ink saved and smaller pdf files.

Then who would be worried about having a consistent reference angle, certainly not those at some latitudes who otherwise now think their GEM is unusable.

[dph1nm]

The plane of the case no longer matches the plane of the earth/Earth and the 50deg angle doesn't point where it should.

Yes but the whole point is that an EQ mount needs to be polar aligned. Once you have done that it really doesn't matter where the tripod is.

By the way, to all those obsessed by levelling their mounts to a fraction of a degree, especially alt-az, I would point out that it is the mount head which you should be levelling, not the tripod.

So as I have yet to see a manufacturer who guarantees their tripods are precisely square on to the mount head, all those fancy spirit levels in the tripod legs etc give no more than an illusion of precision.

NigelM

[Etoille]

FLO used to do a bubble level that used to sit on a plate that fitted between the tripod and mount and is enough to provide a reasonable indication that the mount is level. Not sure if they still do them though. Couldn't find it on their website.

[StevieDvd]

Get an old 1.25 dust cap and stick one of those circular levels to it and you can put it in one of the tripod eyepiece holes for rough levelling.