Compass help needed

[N201MKTurbo]

This is what I use for a master compass. 
 

You can’t use them in an airplane, especially one with a magnetic problem. It is totally uncompensated. It will have more error than the built in compass.

[DXB]

6 hours ago, Nukemzzz said:

 

The cone heater addition thing is confusing me.  Adding something in series will reduce the current, not increase it, because it can only increase the resistance (Well...unless you inserted a capacitor but lets not get crazy!).  I=V/R  (Voltage is fixed). 

I just took the degauss coil and used it as-is.  It could only be ran for 30 minutes because it would overheat if ran longer.   This is evidence that the amperage, going through the coil, is already as high as you can go without damaging things.  I could smell the plastic getting hot inside after about 15 minutes of use.

 

 

Sorry I should clarify - ideally for safety you should have some kind of resistor in the circuit -we started with a 100W bulb but that wasn't enough current so we went to the 660W cone heater - less resistance, much more current.  The basic design I used is illustrated here: 

 

Edited April 8, 2021 by DXB

[orionflt]

I do have the proper degaussing tool if needed, I thought I said that early on but I may have only thought about it and never sent that out. @DXB, don't attempt to electrocute your self next time I'll meet you at UKT.

Brian 

[luv737s]

Liquid compasses were next adapted for aircraft. In 1909, Captain F.O. Creagh-Osborne, Superintendent of Compasses at the Admiralty, introduced his Creagh-Osborne aircraft compass, which used a mixture of alcohol and distilled water to damp the compass card.^[97][98] After the success of this invention, Capt. Creagh-Osborne adapted his design to a much smaller pocket model^[99] for individual use^[100] by officers of artillery or infantry, receiving a patent in 1915.  That's about how old the thinking is at the FAA!!

Mag Compass should be an option in this century not a requirement, provided you have another means of navigation, which could be your CELL PHONE!!  In 38 years of flight instructing I have only seen one DPE reject a plane for the mag compass.  Not that he cared really but the compass deviation card fell out and was not visible.  We found it on the floor, taped it to the mag compass, and he was happy!  

[EricJ]

4 hours ago, luv737s said:

Mag Compass should be an option in this century not a requirement, provided you have another means of navigation, which could be your CELL PHONE!!  

The Seminole I did my multi-engine training in came from the factory without a compass.   Their check pilot told me he refused to fly it until they got a letter from Piper explaining how it was certified without one.

 

[N201MKTurbo]

5 hours ago, luv737s said:

Liquid compasses were next adapted for aircraft. In 1909, Captain F.O. Creagh-Osborne, Superintendent of Compasses at the Admiralty, introduced his Creagh-Osborne aircraft compass, which used a mixture of alcohol and distilled water to damp the compass card.^[97][98] After the success of this invention, Capt. Creagh-Osborne adapted his design to a much smaller pocket model^[99] for individual use^[100] by officers of artillery or infantry, receiving a patent in 1915.  That's about how old the thinking is at the FAA!!

Mag Compass should be an option in this century not a requirement, provided you have another means of navigation, which could be your CELL PHONE!!  In 38 years of flight instructing I have only seen one DPE reject a plane for the mag compass.  Not that he cared really but the compass deviation card fell out and was not visible.  We found it on the floor, taped it to the mag compass, and he was happy!  

Really,

the majority of aircraft out there still need one to set their DG. unless you have a slaved DG or HSI or one of the new magnetometer slaved electronic HSIs you still need one. It is a cheap backup if you lose all the electrons. 
 

Saying you can use your cell phone as a backup is a slippery slope. Cell phone batteries don’t last forever, so those electrons will fail. Do you want the FAA to mandate that we carry FAA/PMA cell phones?
 

Try steering a plane with no directional guidance, especially in IFR or no horizon conditions.  

[testwest]

Nuke I hope this is one of the threads you looked at:

https://mooneyspace.com/topic/36590-magnetic-compass-way-off/?tab=comments#comment-628292

It was my mounting bracket that was magnetized! I got my vertical card compass walked in finally, but it was much easier than before without that magnetized bracket. Still, if I get another failure I am going with the SIRS compass. The previous advice you received in this thread regarding that compass is well founded.

Hope your PPL went well!

[Nukemzzz]

On 4/7/2021 at 3:12 PM, GeeBee said:

My response was to those above who say as long as it is "on the card" it is "ok". What you are doing is good work, but I have to tell you de-gaussing is a short term fix. Too much current flows through the frame for it to hold. 

 

I think I know how it became magnetized. When I flew the plane home after buying it the exhaust popped and it was immediately down for a month and a half in the winter. While waiting for the exhaust overhaul I installed an EDM-730 and had a space heater in the plane with me for much of it since the hangar wasn’t heated and I’m in Indiana. I found out later about this steel cage in the plane that gets magnetized if a high current wire gets too close. At least I’m hoping this is it. Also, I know of no other way to fix it than to demag. 

[Nukemzzz]

3 hours ago, testwest said:

Nuke I hope this is one of the threads you looked at:

https://mooneyspace.com/topic/36590-magnetic-compass-way-off/?tab=comments#comment-628292

It was my mounting bracket that was magnetized! I got my vertical card compass walked in finally, but it was much easier than before without that magnetized bracket. Still, if I get another failure I am going with the SIRS compass. The previous advice you received in this thread regarding that compass is well founded.

Hope your PPL went well!

It was actually.  I have been looking for a degauss gun like the one that raptor had on that last post. Looks better suited than the crt coil that I used. Both my old whiskey and the new vertical card compasses have aluminum brackets and I have brass screws. It was coming from the center tube mainly it seems... I’m think I have it licked now. At least I hope. 

[Nukemzzz]

On 4/7/2021 at 8:09 PM, DXB said:

Sorry I should clarify - ideally for safety you should have some kind of resistor in the circuit -we started with a 100W bulb but that wasn't enough current so we went to the 660W cone heater - less resistance, much more current.  The basic design I used is illustrated here: 

 

I see, I knew I was missing something!  Thanks for the clarification. 

[GeeBee]

32 minutes ago, Nukemzzz said:

I think I know how it became magnetized. When I flew the plane home after buying it the exhaust popped and it was immediately down for a month and a half in the winter. While waiting for the exhaust overhaul I installed an EDM-730 and had a space heater in the plane with me for much of it since the hangar wasn’t heated and I’m in Indiana. I found out later about this steel cage in the plane that gets magnetized if a high current wire gets too close. At least I’m hoping this is it. Also, I know of no other way to fix it than to demag. 

Except the heater is AC.

I've seen people go so far as to use DC welders to generate de gaussing current. Again it works for a while.

 

[luv737s]

On 4/8/2021 at 1:44 PM, N201MKTurbo said:

Really,

the majority of aircraft out there still need one to set their DG. unless you have a slaved DG or HSI or one of the new magnetometer slaved electronic HSIs you still need one. It is a cheap backup if you lose all the electrons. 
 

Saying you can use your cell phone as a backup is a slippery slope. Cell phone batteries don’t last forever, so those electrons will fail. Do you want the FAA to mandate that we carry FAA/PMA cell phones?
 

Try steering a plane with no directional guidance, especially in IFR or no horizon conditions.  

In reality I set my DG to the taxiway which is parallel to the runway I am using and then again using the runway I am taking off from.  I have flown twice with no DG in the WX with my Mag compass only, but in modern times, I don't hesitate to turn on my IPAD and use the AHARS.  Electrons fail, hear that all the time.  How about all the juice leaking out of your mag compass?  Any failure is not good, but it's time to get alternatives so we are not grounded for an ancient piece of equipment.