Levelling a mount without a spirit level?

[jbdtaylor]

Hey guys, I'm new here so I hope I'm not ballsing up somewhere, couldn't seem to find anything on this anywhere else.

I have a Skywatcher Explorer 130p with a Supatrack mount.

Now, this mount does not have a spirit level anywhere on it. So my question is, what is the best way of levelling it?

I do have a spirit level, but not a round one, just a regular one for checking if something is straight only on one axis.

My solution when I went out tonight was to put it across the accessory tray near each of the three corners, and adjust the legs until the bubble was in the middle when it was placed any of them.

While I managed to get that done pretty easily, I don't know if the tray is actually parallel with the drives for the motor!

Does anyone know if this is fine; the accessory tray should be as flat as the drive, or at least only be out a negligible amount. Or if I'm just doing it totally wrong!

[glowjet]

Maybe a solution to this is to obtain one of those small circular plastic bubble levels from a hardware shop, then attach this to the tripod baseplate top in some way or another, it will be your least expensive Astro outlay to date I should think, it will also check whether your accessory tray is level with the rest of the tripod, for future reference

John.

[cotterless45]

I think that the circlar spirit levels are inaccurate .

I did see a camera cube spirit level on fleabay which went into the flash bracket, this could be stuck on somewhere useful.

Is there nowhere beneath the tray that you can fit a plum bob ?

If you're using the scope in the same place you could just lay 3 tiles and with a long spirit level or wood get them level to sit the tripod upon, neat,

Nick.

[Tinker1947]

If its a EQ mount just getting it so it looks level will do.........

[Stu]

Levelling as you are doing should be fine. I think your mount is a tracking alt-az so the only issue will be how close it gets to the first alignment star. Give it a go, should be ok, you may just have to slew a little to the first star but that's not so unusual

Stu

[Stargazer33]

Is there anyway that you could set your scope to 0 deg altitude? You could then place your spirit level on top of your scope tube and level it that way, by adjusting the legs. You could then just rotate the scope in azimuth and check that the bubble doesn't move outside of the lines as you rotate. That might compensate for any miss-alignment in the mounting plate of your tube too.

Just a thought, not sure if it would work or not!

[jbdtaylor]

plumb-bob does sound like a good idea. Although southerndiver357, your idea with putting the spirit level on top while the OTA is at 0 latitude sounds best, if I get it to turn around with the spirit level on top then I could check that it's fine in all directions!

Cheers guys!

[Rustmonkey]

I use a spirit level. Just take the head off, drop the level across the 3 plains ( direction of legs), level it up and then replace the head......job done. A bit of a faff but works fine.

[cantharis]

I use a spirit level. Just take the head off, drop the level across the 3 plains ( direction of legs), level it up and then replace the head......job done. A bit of a faff but works fine.

I do EXACTLY the same !!

[LukeSkywatcher]

You could try a Wixey. Its a digital angle reader.

[breezy]

There's an inclinometer app on iPhone , just lay it in the tray and go from there , I don't know if you have to get it 100%

[jbdtaylor]

I use a spirit level. Just take the head off, drop the level across the 3 plains ( direction of legs), level it up and then replace the head......job done. A bit of a faff but works fine.

For some reason I hadn't thought to take off the top part of the mount! That's perfect.

Thanks everyone for your suggestions. I don't know if it has to be 100% perfect, but I would prefer it to be haha!

[Stu]

It doesn't have to be perfect, but the nearer you are, and the more accurately pointing north, the.closer you should get to your alignment stars

Stu

[x6gas]

It doesn't have to be perfect, but the nearer you are, and the more accurately pointing north, the.closer you should get to your alignment stars

Stu

Surely it's the accuarcy of your polar alignment that dictates how close your initital alignmment stars are? In truth, a GEM doesn't have to level at all - what's important is that the RA axis is aligned with the North Celestial Pole and so as long as you have enough adjustment in you Alt and Az knobs you can achieve this without the tripod being level, or the tripod itself pointly exactly North (looking at it another way, the tripod doesn't have to be exactly level any more than it has to be pointing exactly North).

The only purpose of having the tripod levelish is that it gives you a better starting point for the polar alignment; in my case I roughly level the mount so that I can be sure that Polaris unabiguously appears in my polar scope...

[russellhq]

I've heard a level mount helps with balance i.e. centre of gravity and also helps alignment after a meridian flip. Though I don't know enough myself to know whether that's true.

I guess a level mount also helps if you don't have a permanent set-up. It'll give you a datum next time you set up so your polar alignment won't need as much tweaking. That's the hope anyway!

[great_bear]

The Sky-Watcher SupaTrak mount is Alt-Az - not an EQ mount - so yes, it most certainly does have to be level for the tracking to work properly!

Furthermore, since (using the supplied controller) it is only a tracking mount, not go-to, then alignment stars don't come into the equation at all.

I don't recommend using the accessory tray as a reference.

On my SupaTrak, I use the a levelling method similar to those outlined by others above: With all three legs adjusted to have a bit of spare travel in them, and the mount head unscrewed and placed to one side, I place a bog-standard spirit level across the top of the tripod approximately above where two of the legs join the assembly. After I've got that measurement level by adjusting either or both legs, I then slide the spirit level across to measure between either of those two legs just done, and the one remaining leg - adjusting that one remaining leg up or down to get things level. After a final check by swivelling the spirit level around to check it's all definitely leveled up in all directions, you're good to go.

Don't forget to set the latitude to your current location if it's changed since you've last set it, and make sure you power up at 0 degrees (i.e. scope horizontal) both when you set the latitude and on subsequent observing sessions.

J.

[Stu]

Totally correct about PA being the significant factor in pointing accuracy on an EQ mount, it doesn't matter if the tripod is totally level so long as PA is correct.

However, my understanding is that the Supatrak is an Alt-Az tracking/goto mount, in which case levelling to mount properly and pointing north accurately will be all you can do to ensure the initial alignment stars are found easily.

Stu

[Stu]

Must type faster.....

...I was wrong about the alignment stars bit, but at least correct about it being alt-az and thus needing accurate levelling/north pointing.

Stu

[jbdtaylor]

Thanks great_bear, perfect info. For some reason there doesn't seem to be much info on the mount on the internet, so good to get an answer from someone who also uses the same type.