Carbon Fibre voltage conductance!!! Watch out.

[nealj4]

In trying to resolve the reasons for a crash I had with my Tarot 680 I stumbled across something that everyone should know ( many of you might already.) The tarot , like many MRs have two centre plates. The power distribution board does not conduct electricity ( within the carbon fiber itself) just the positive and negative circuit within. But ( at least on my Tarot) the other plate does conduct electricity. So be carefully if you have any bare connections they don't touch the plate. Better yet,take a voltmeter and put it on the resistance scale and put the two leads anywhere on the plate to determine if yours is conducting.
Better to be safe.

 

[gtranquilla]

PDBs = Power distribution boards are made of PCB non-conductive material (not carbon fiber) and then are clad on one or both sides with thin copper that is ultimately etched to create PDB + and - conductive traces which is finally painted over with black paint or epoxy.
Caution is needed when mounting a PDB board onto a Carbon Fiber airframe.

Carbon fiber airframes are a composite consisting of both conductive and non-conductive material (epoxy is non-conductive - carbon fiber is low resistance and essentially conductive). A multimeter ohms test will show you high resistance and one spot by suddenly a very low resistance at another location depending on where the probes touch the CF composite. Also IMHO - PDB standoffs should not be aluminum but nylon and without metal bolts running thru them as an extra precaution.

 

[Av8Chuck]

Good advice.

 

[Toymaker]

Radio signals have a tough time passing through it because of carbon's conductivity. They have been making automotive spark plug wires with "carbon fiber" "graphite" for decades!

 

[nealj4]

Thanks guys for clearing that up!!
Great stuff.