Remote Indicating Compass- needle pivot off center

[Terry Dactil]

The needle pivot point is not concentric with the circular scale. It is on the vertical center line, but is some distance below the horizontal center line.

The tail of the pointer needle should be 180° off the head.

It is OK on the N-S axis.

But will have about 10° errors on Easterly and Westerly headings. (The needle should be horizontal if indicating East or West}.

 

[Hiob]

Lower your head to be on the same level as the center point of the instrument. The needle is quite a bit in front of the scale. I assume the problem is gone then.

 

[Terry Dactil]

On 2/7/2023 at 6:45 PM, Hiob said:

The needle is quite a bit in front of the scale.

 

Yes. You are right and I stand corrected. It is a parallax problem with the needle so far away from the scale and not a shaft/pivot point problem.

From a high viewpoint here is what appears to show 270°

But down at a level viewpoint it is really 280°

Here is what 270° looks like from the level viewpoint.

And how we see it from the normal viewpoint.

So, the RI also has errors. And I thought the P8 was the bad one!

Update:

I have had it explained to me by Bozon. Thank you .........

"... the correct way to use the RI is by setting the broad, manually rotating arrow to the direction you wish to keep. Then, the heading-indicating needle needs to be parallel to it - it stays parallel at all perspectives and is easy to monitor  by a quick glance towards the dial. No need to read the numbers during cruise. "

(So, unlike the modern compass, this one is not designed to tell you what heading the aircraft is on at all times, but to be accurate in keeping you on the one heading you have selected).

Edited February 10, 2023 by Terry Dactil
It all makes sense now!