Altitude scale on Skywatcher EQ2 mount

[FenSkies]

I need a sanity check.

Just how inaccurate can I expect the latitude scale on the Skywatcher EQ 2 mount to be?

With the altitude set correctly, the mount levelled pointing to magnetic North, and the scope in the home (top) position, my understanding is that rotating the mount a little should bring Polaris into the field of view.

I am in Cambridge UK at latitude 52 and a bit, but I'm having to wind the mount to 60 degrees, according to the scale, to get Polaris in the FOV.

Am I doing something stupid, or is the altitude scale hopelessly out? The tripod was levelled using a circular bubble level before fitting the mount.

Help! Thanks.

[Cornelius Varley]

True north not magnetic north. The tripod doesn't need to be absolutely level, near to level is sufficient. Probably best to ignore the latitude scale and just use it as an approximate guide. 

[FenSkies]

12 minutes ago, Cornelius Varley said:

True north not magnetic north. The tripod doesn't need to be absolutely level, near to level is sufficient. Probably best to ignore the latitude scale and just use it as an approximate guide. 

Thanks Peter. Yes, magnetic North was just a starting point to rotate from.

I take it I can assume the altitude scale is nowhere near accurate then?

I've installed an inclinometer app on my phone now, so I'll sit the phone on the bar between the scope rings to roughly set the altitude.

[Bugdozer]

The difference between magnetic/geographic north shouldn't give you an 8 degree error. It sounds like the scale is not lined up right. It may be adjustable? Then once you have the pole in sight you can manually calibrate it?

[Elp]

Considering how small such scales are and likely not made to any sort of accuracy tolerance I wouldn't take much notice in it. The number however maybe close to a target, I've noticed some altitude scales are printed "backwards" so they're not set at the number one would expect but 90 minus though yours is no where near.

Edited November 7, 2023 by Elp

[FenSkies]

2 hours ago, Bugdozer said:

The difference between magnetic/geographic north shouldn't give you an 8 degree error. It sounds like the scale is not lined up right. It may be adjustable? Then once you have the pole in sight you can manually calibrate it?

 

2 hours ago, Elp said:

Considering how small such scales are and likely not made to any sort of accuracy tolerance I wouldn't take much notice in it. The number however maybe close to a target, I've noticed some altitude scales are printed "backwards" so they're not set at the number one would expect but 90 minus though yours is no where near.

 

Yep, I think the scale must be way out. With the mount set to 52 on the scale, the inclinometer app on the phone (placed on the bar the scope rings are fixed to) reads 47 degrees.