Bubble level

[bottletopburly]

Whilst in Axminster tools spotted a large bubble level looked about right size to fit on eq5 spreader plate and it does perfect fit used clear silicon cost was only about £3.50 ish

[Tony H]

Nice.  And a great price.  I'm using a traditional foot long level with 3 level tubesin it at present.

I think you could help me here as I'm fairly new to all this.

If I used a round bubble level approach as you have, should I buy 3 and put one adjacent to each leg to get my mount level?

Thanks in advance for any help here.  :-)

[steviegall]

nah tony, the round bubble acts as a level for all the legs, 

once its in the middle your platform(whatever that may be) will be level

you just need a flat surface to put it on, adjust the 3 legs until the bubble is in the centre = dead level on all axis

[Tony H]

Cool

I'll be getting one of these then.

Thanks for that.

[laudropb]

Good idea. Think I will give it a go. Thanks for posting.

[bottletopburly]

Link here http://www.axminster.co.uk/bullseye-level

[bottletopburly]

Oh maybe available at other hardware stores incase link breaks any rules

[Beulah]

That's a brilliant and simple idea.

[JamesF]

They're handy, those.  I bought two or three.  I have one on my dob base (it has height-adjustable feet).

James

[ollypenrice]

You know that EQ mounts don't need to be level? It is widely believed that they do but they don't. An approximation of level can be helpful in terms of repeatability and reduced interaction between axes during drift alignment but on SW mounts you level so as to set your polar scope reticle to vertical. Now think about this. How accurate is your polarscope anyway? Is it worth finessing the tripod legs for ten minutes in view of this accuracy? I'm going to say not. Nor do I think the spreader plate is likely to be precisely parallel with the mount top.

Takahashi got it right. You can't even adjust their tripod legs to level the mount but their fast PA routine is the best there is. Mount levelling is worth no more than a minute in my view. Spend the time elsewhere.

Olly

[bottletopburly]

It gives me something to do just done polar scope alignment ,cone error next

[bottletopburly]

Update levelled tripod today took head off checked with spirit level it was out so reset level as I knew tripod was now level as long as I set up with spreader in same orientation .

[cjdawson]

You know that EQ mounts don't need to be level? It is widely believed that they do but they don't. An approximation of level can be helpful in terms of repeatability and reduced interaction between axes during drift alignment but on SW mounts you level so as to set your polar scope reticle to vertical. Now think about this. How accurate is your polarscope anyway? Is it worth finessing the tripod legs for ten minutes in view of this accuracy? I'm going to say not. Nor do I think the spreader plate is likely to be precisely parallel with the mount top.

Takahashi got it right. You can't even adjust their tripod legs to level the mount but their fast PA routine is the best there is. Mount levelling is worth no more than a minute in my view. Spend the time elsewhere.

Olly

After a little thought, it does make sense that there is no point Alt-Az aligning the scope, then polar aligning it, other than to make the process more repeatable.  This does make it less effort if you are going to setup a peir, as you can simply build a column with a flat top, and fixings for the EQ head/wedge.   For polar alignment the only things that matter are the RA and Dec alignment.  For a wedge based scope, that's simply rotating the Az part of the wedge, then setting the Alt part.

However, for tripod work, with my scope, it's easier to make sure that the tripod is level, then I can put the scope on, use a polar scope to align the wedge to polaris, Then life the 20Kg of scope into place and start performing the drift alignment.  As I tend to observe from the same place each time, I will know that once the alignment has been done the first time, it's unlikely that I'll need to do much in the way of adjusting the Dec each time.  It should only require the base of the wedge to be corrected in Az.  Which will make life easier.

As for the time taken to level the tripod, without having the OTA attached, I'm able to level my tripod in about a minute with the use of a spirit level (foot long job) so for the amount of time that it takes, I don't think it will hurt to do it.  Having the whole repeatable part means that the drift alignment phase would be quicker on the 2nd setup as there will be fewer corrections needed.

[theghettostylus]

I am going to agree on the leveling aspect and accuracy of polar scopes.

I know my mount is of lower quality as it is the eq 3-2 on a home made level pier but I know for a fact the whole in my mount for the polar scope isn't bored correctly as it will never fully align and always has a bit of shift but then if I was to drift align then this would correct that error. What is level anyway? I read somewhere you should calibrate your spirit levels anyway and I know for a fact the one in the mount is way off anyway so I just do a quick level and leave it at that. But I am soon to try the drift alignment process and see how inaccurate my mount actually is.

[de0s]

You know that EQ mounts don't need to be level? It is widely believed that they do but they don't. An approximation of level can be helpful in terms of repeatability and reduced interaction between axes during drift alignment but on SW mounts you level so as to set your polar scope reticle to vertical. Now think about this. How accurate is your polarscope anyway? Is it worth finessing the tripod legs for ten minutes in view of this accuracy? I'm going to say not. Nor do I think the spreader plate is likely to be precisely parallel with the mount top.

Takahashi got it right. You can't even adjust their tripod legs to level the mount but their fast PA routine is the best there is. Mount levelling is worth no more than a minute in my view. Spend the time elsewhere.

Olly

I definetly agree with Olly on one thing: you've got no guarantee that the spreder is paralel with the mount's top surface. As for the necessity of leveling an EQ mount, I agree I'm not so experienced, but I was under the impression that it's guite a big deal. At least part of it. I agree that if the mount is not leveled in the North-South direction this can easily be fixed with the Alt adjustment bolts during the drift alignment procedure. Whoever, if the mount is not leveled on the East-West direction, this cannot be fixed with the Az adjustments and you end up with a tilted RA axis. Am I mistaken?

[ollypenrice]

Let's call on Harry Potter for a demonstration! Harry will cause a steel shaft, the right thickness to fit snugly down your mount's polar axis, to hover in a fixed position and pointing precisely at the celestial north pole. No force, however strong, can affect the polar alignment of this hovering shaft. Thanks Harry.

Now we slip your mount's polar axis over this hovering shaft. The mount becomes perfectly aligned, by definition. Whatever we now do to it it will remain perfectly aligned. So let's attach a pier to it but a pier which doesn't quite reach the ground. We loosen the polar alignment bolts and point the pier wherever we like - and this has no effect whatever on polar alignment.

On Skywatcher mounts, and the many which are like them, levelling serves only to put the polar scope reticle into the right orientation. If doing a drift alignment there will be a slightly reduced need for multiple iterations but it is slight.

Since the EQ6 is very obviously a copy of the Takahashi EM200 in most respects, it's a shame that they didn't also copy Takahashi's polar alignment routine. You cannot level a Tak tripod. It has no adjusters. The bubble level is where it should be, on the RA housing. It is easier to rotate an RA housing than to level a tripod. This sets the reticule to the correct orientation. There is then a time zone offset on the mount which means that this orientation is locally correct. The reticule resembles a planisphere so you rotate the time to meet the date and this gives you the right position for the Polaris box. Centre Polaris and you're done. Why most other manufacturers have not picked up on this system is a mystery, though I think the Vixen Atlux uses it.

Olly

[laser_jock99]

Might I also remind any potential pier constructors at this point - leveling bolts & plates serve no purpose either! Except, perhaps to make the scope and mount less stable.......

All the adjust you need is built into the mount.

[Mr Spock]

It's a simple, inexpensive and useful thing to have. Like many others though I never bother leveling the mount - near enough is good enough as they say.

[ollypenrice]

Might I also remind any potential pier constructors at this point - leveling bolts & plates serve no purpose either! Except, perhaps to make the scope and mount less stable.......

All the adjust you need is built into the mount.

Exactly so. All that concrete to end in three of four levelling bolts...

Olly

[Scott]

You know that EQ mounts don't need to be level? It is widely believed that they do but they don't. An approximation of level can be helpful in terms of repeatability and reduced interaction between axes during drift alignment but on SW mounts you level so as to set your polar scope reticle to vertical. Now think about this. How accurate is your polarscope anyway? Is it worth finessing the tripod legs for ten minutes in view of this accuracy? I'm going to say not. Nor do I think the spreader plate is likely to be precisely parallel with the mount top.

Takahashi got it right. You can't even adjust their tripod legs to level the mount but their fast PA routine is the best there is. Mount levelling is worth no more than a minute in my view. Spend the time elsewhere.

Olly

quite correct, but for the sake of a few seconds, why not? as you said, it helps for drift alignment and why not get your alt/az to actually be alt/az.

the time its taken me to type this, I'd have leveled my mount.

[Scott]

Might I also remind any potential pier constructors at this point - leveling bolts & plates serve no purpose either! Except, perhaps to make the scope and mount less stable.......

All the adjust you need is built into the mount.

True, but why would anyone go to the trouble of building a pier and not take a few minutes to do so square/level. for this reason I don't need leveling bolts either.

I just don't get why anyone would build something permanent and not do it right?

[ollypenrice]

It's a matter of 'how right is right.' People fit levelling bolts to fine tune their levelling after concrete setting, settlement and over time. This just isn't necessary.

On the tripod levelling question, I don't find I can get them precisely level in a minute. It takes me longer. Time spent going from 'close' to 'perfect' is, I'm arguing, time wasted. 

Olly

[laser_jock99]

It's a matter of 'how right is right.' People fit levelling bolts to fine tune their levelling after concrete setting, settlement and over time. This just isn't necessary.

On the tripod levelling question, I don't find I can get them precisely level in a minute. It takes me longer. Time spent going from 'close' to 'perfect' is, I'm arguing, time wasted. 

Olly

My advice would be quickly get mount level but spend a good deal more time doing two or three iterations with a PA routine.

Regarding the levelling of the pier- this important step should be whilst the concrete is setting- get it right at the start then no further adjustmentt is required.

[astronymonkey]

I would agree that polar aligned mounts dont necessarily need levelling as long as the axis is aligned but I do find it helps a lot woth alt az goto and push to systems where there is no fixed axis aligned. This is especially important when doing a single star align , which is all my push to uses , or if I do a synscan 2 star align and the two alignment stars are not very far apart.

For levelling though I use a bubble level app on my phone and find it works very well.

Cheers

[Stub Mandrel]

I wouldn't put too much faith in those bubble levels - their sensitivity as much as accuracy. If you did have to level your mount with the same sort of accuracy you want for polar alignment, say an accuracy of 1 minute, you'd need a level like THIS Moore and Wright one, a snip at £145...