Compass Mounting

[Forrest Barber]

Re: Compass Mounting

At the factory with the F-19's, I tested #74 thru # 154 alternating with the other test pilot. I have been involved with building up many other projects over the years.
At the factory , the welders followed a prescribed pattern of welding on the fuselages; however, once in a while at flight test time , I could not get a compass to come in due to more than 10 degree Deviation.
We used an old automotive 'growler" Kenny & I got real good at putting it up to the tubing in side the forward cabin. I would hold her in place, nod my head and jerk it rapidly away from the tube that it encircled while Kenny unplugged the unit. ( Dorothy could not afford a switch , I guess).. This worked to degauss (sp) the tubes. Sometimes three to five pulls had to be done. Once we had to use permanent magnets but that was on a ship withg a lot of radio and lights turned on.
Our compass rose was in flight with cruise power.

[Jim Meeker]

Re: Compass Mounting

Paulnuss
I tried deqaussing(sp) with a bulk tape demagnitizer from Radio Shack, did not do any good on my plane. When I got the compass I saw these as an option and got them too. I am more familiure with the concept on boats where you used to see similar balancing balls or compensators on big sailing ship compass binnacles. They are magnetic one has a red dot the other a green. The compass is mounted in the standard place on the cross bars above the dash board. The compensators attach to the bottom of the compass. I am not sure I can accurately remember the adjusting process since I did it several years ago but I think it was something like: put the internal adjustment screws on compass to neutral, mount the compensators adjust to neutral, line the plane NS note deviation, line the plane EW note deviation, adjust either the green or red to take out half the EW deviation, aline NS adjust the other ball to take out half the deviation, reline EW and use compass adjuster to fine tune, reline plane to NS and use compass adjuster to fine tune, Recheck and fine tune with engine running. Any way the instructions were very complete and easy to follow and by using them my compass now swings true.
I attached two cropped pictures, that if you look close (especially on compass2) you can see the complensators on either side of the compass. You can't see the compass very well because I fabricated a small aluminum backing plate on which I hung the vertical compass. It is the backing plate you see in the picture.
Hope this helps
Jim

[cpirrmann]

Re: Compass Mounting

Thanks to everyone for the plethora of infor to chew on. But, it's sounding like I should leave it in the panel where it is.

[Carl E. Carson]

Re: Compass Mounting

I have a "bubble" compass with the bubble being broken. Does anyone know where a replacement bubble glass might be available.

Carl Carson
[email protected]

[Winston L.]

Re: Compass Mounting

Buell Powell who is a member has a source for those lenses.

Winston

[Jim Meeker]

Re: Compass Mounting

I have seen those "balancing balls", actually in corporate aircraft (e.g. King-Air, C-525). I wasn't sure how and if they would function in a steel-tube frame that is already magnetized. The corporate jobs are of course not of steel construction in the windshield area. Are they actually magnets themselves? Would you please explain where you mounted them? How and if you adjust the balancing balls? Then what about the adjustment of the compensating magnets in the aircraft compass? I am very interested...

Here are some better pictures of the compensating balls and how they are attached.

[paulnuss]

Re: Compass Mounting

Thanks for the photos; I must get a set. It would be nice to have a functioning compass after all these years.