Wires, antennae and FCs near magnets

[orange_rc_pilot 0]

Hi all,

 

I'm currently designing a VTOL aircraft, (I know, very ambitious for someone with not that much experience!), and there will be a few magnets in it to hold battery hatches in place etc. 

 

I was wondering if having wires carrying either power or signals (i.e. battery leads/BEC wires and servo wires) would be affected in any way by being very close to the magnets? They are 1.6kg 1.5x6mm neodymium magnets, and the wires will be about 20mm away from the magnets, or perhaps closer, with thin foam (5mm) in between.

Also, would mounting a receiver antenna next to a magnet have bad effects?

Finally, would mounting a flight controller (I'll be using the KK2.1 hard case) near the magnets mess with the accelerometer?

 

Essentially, can magnets damage components or disrupt wiring?

 

Thanks very much,

Sevan.

[Pilot Ben 28]

Any metal can potentially block signal from your tx to your rx but I wouldn't have thought there would be any effects on the wiring on flight controller. As with the accelerometer I couldn't say As long as your rx antennas are far enough away you should be in buisness....

[orange_rc_pilot 0]

18 minutes ago, Pilot Ben said:

Any metal can potentially block signal from your tx to your rx but I wouldn't have thought there would be any effects on the wiring on flight controller. As with the accelerometer I couldn't say As long as your rx antennas are far enough away you should be in buisness....

Thanks very much for the reply Ben. I'll bear that all in mind when I get to installing the wiring 

 

Sevan

[Bravedan 106]

The VTOL Eflite Convergence has a magnet attached canopy and that was designed for FPV. (cynically that's maybe why some are falling out of the sky cos it would NOT be the pilots or Spektrum, would it!!)

However, think about Quads, they have LOTS of powerful magnets in the motors hurtling round and round (I have just completed a 250 that has 1.7kg of thrust PER MOTOR, getting close to 7kG pull, so imagine the magnetic power!!!!!), and the ESCs generate all sorts of RF clutter, often all jammed up together. The trend is to smaller quads with bigger motors and small high pitch or multi blade props on short arms, so motors are increasingly getting very very close to the FC, etc.

ALSO, there's another trend to have the FC, OSD and PDB all in the one board ( sometimes the ESCs as well, or in a 4 in 1 board stacked on top ), so to access the OSD the camera feeds the VTX via the FC board.

Its much more necessary to filter the power feeds to Camera and VTX or at least check they are filtered if separate items, something most FC (but not all) do reasonably well as long as you take the feeds from the right place as designated. (Yes, I have seen people hook them off the ESC supply line!)

 

HTH,

 

Dave

On 01/08/2017 at 10:32 PM, orange_rc_pilot said:

would mounting a receiver antenna next to a magnet have bad effects?

Finally, would mounting a flight controller (I'll be using the KK2.1 hard case) near the magnets mess with the accelerometer?

Sevan.

The VTX Antenna needs to be as far from ANY metalwork or carbon plate frames, etc as you can practically get, if poss so it is line of sight to the VRX antenna.

Unlikely to affect accelerometer, Magnetometer is another matter!!!

[orange_rc_pilot 0]

On 03/08/2017 at 7:33 PM, Bravedan said:

The VTOL Eflite Convergence has a magnet attached canopy and that was designed for FPV. (cynically that's maybe why some are falling out of the sky cos it would NOT be the pilots or Spektrum, would it!!)

However, think about Quads, they have LOTS of powerful magnets in the motors hurtling round and round (I have just completed a 250 that has 1.7kg of thrust PER MOTOR, getting close to 7kG pull, so imagine the magnetic power!!!!!), and the ESCs generate all sorts of RF clutter, often all jammed up together. The trend is to smaller quads with bigger motors and small high pitch or multi blade props on short arms, so motors are increasingly getting very very close to the FC, etc.

ALSO, there's another trend to have the FC, OSD and PDB all in the one board ( sometimes the ESCs as well, or in a 4 in 1 board stacked on top ), so to access the OSD the camera feeds the VTX via the FC board.

Its much more necessary to filter the power feeds to Camera and VTX or at least check they are filtered if separate items, something most FC (but not all) do reasonably well as long as you take the feeds from the right place as designated. (Yes, I have seen people hook them off the ESC supply line!)

 

HTH,

 

Dave

The VTX Antenna needs to be as far from ANY metalwork or carbon plate frames, etc as you can practically get, if poss so it is line of sight to the VRX antenna.

Unlikely to affect accelerometer, Magnetometer is another matter!!!

Hi Dave, thanks so much for your detailed response. Sorry I couldn't reply earlier, I was abroad with bad connection. I had forgotten just how strong motor magnets are, and electronics perform fine around them! Hopefully it shouldn't cause me any issues then. I'll still put my antenna about 5-10cms away from the magnets, juuuuust in case, but I certainly won't obsess over having them a metre apart! I'm not planning to use any FPV gear, so no issues there  

Thanks again,

Sevan