EQ Platform Adjustment

[Mr Spock]

My EQ platform tracks pretty well. Other than that new motor I fitted which is erratic (I'm putting the old one back on tomorrow).

However, I do find I have to, when pointing West, lift the scope up every now and then. I assume because the previous owner was at a different latitude and it was set for there. I'm guessing as that was south of here I'll have to lower the South of the platform to tilt the scope up a little. Is that correct?

This is probably going to be trial and error as I've no clue how to measure it.

[michael8554]

Hi Michael

I don't have an EQ Platform, so I'd guess:

Google the Latitude for where you are.

Let's say it's 40N.

With the base level, set the tilt angle to 90-40 = 50.

Alternatively:

Point north.

With the scope tube parallel to the tilted plate.

Alter the tilt until you can see Polaris in the finder, then with increasing mag eyepieces.

Close enough for Visual use.

Or finally there's  online info for the Watchhouse EQ platform.

Michael

Edited April 27, 2023 by michael8554

[PeterStudz]

There’s some good info about doing just that from John at the end of page 5…
 

I polar aligned mine following the details here (right at the end of the link) It’s a faff but I did it once and marked the position of the platform on my patio. As long as I place it right there it’s all that’s needed to be bang on.

http://www.astrosurf.com/aheijkoop/Equipment/EqPlatfor2.htm

[Mr Spock]

Aligning to North is easy - my patio is perfectly aligned. It's the azimuth I'm confused about - something tells me I need to lower the S or raise the N for it to track accurately. With the old motor, E-W tracking was perfect. It's that little bit of N-S drift I need to eliminate.

[PeterStudz]

8 minutes ago, Mr Spock said:

Aligning to North is easy - my patio is perfectly aligned. It's the azimuth I'm confused about - something tells me I need to lower the S or raise the N for it to track accurately. With the old motor, E-W tracking was perfect. It's that little bit of N-S drift I need to eliminate.

Polar aligning will fix that as it includes raising/lowering the platform depending on how Polaris behaves. 

 

[westmarch]

14 hours ago, Mr Spock said:

My EQ platform tracks pretty well. Other than that new motor I fitted which is erratic (I'm putting the old one back on tomorrow).

However, I do find I have to, when pointing West, lift the scope up every now and then. I assume because the previous owner was at a different latitude and it was set for there. I'm guessing as that was south of here I'll have to lower the South of the platform to tilt the scope up a little. Is that correct?

This is probably going to be trial and error as I've no clue how to measure it.

Hi Michael,

I suspect you and Peter are correct, you will have to correct the height of the south bearing. If the platform is level, and you wish to correct for a more Northerly latitude, you will need to depress the southern bearing height. 

If you start by incrementally raising the northern bearings with plywood packers, you will get an idea of the amount of South bearing shimming needed. 

Alternatively, you can just incorporate the Northern bearing packers into your set up. 

Just remember your design is optimised  for a different latitude, it will always be somewhat of a comprise  and the bigger the difference in latitude, the bigger the compromise  

John

Edited April 27, 2023 by westmarch

[AstroMuni]

2 hours ago, Mr Spock said:

Aligning to North is easy - my patio is perfectly aligned. It's the azimuth I'm confused about - something tells me I need to lower the S or raise the N for it to track accurately. With the old motor, E-W tracking was perfect. It's that little bit of N-S drift I need to eliminate.

Before you make alterations to the actual platform, suggest you put props under the unit to raise the level at the appropriate end. That will give you an idea of how much correction is needed. And then you can decide best approach.

[Mr Spock]

Thankfully the feet are on bolts. All I have to do is raise the north feet - adjust then try. It’s not a big problem as it is, but I’d like it to be spot on.