---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 07/29/04: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:32 AM - Shadin Digidata and JPI fuel flow interface (Ron Koyich) 2. 04:34 AM - Down the yellow brick road . . . (Robert L. Nuckolls, III) 3. 05:32 AM - Grounding hinges in composite aircraft (Greg Reid) ________________________________ Message 1 _____________________________________ Time: 12:32:09 AM PST US From: "Ron Koyich" Subject: AeroElectric-List: Shadin Digidata and JPI fuel flow interface --> AeroElectric-List message posted by: "Ron Koyich" Has anyone on the list constructed a 'Y' cable to pull off the fuel flow transducer pulses from the Shadin DigiData to drive fuel flow on a JPI EDM-760? It looks to me the easiest place to do this would be at the back of the Shadin indicator. Their diagram suggests running additional wires all the way out to the transducers at the engines. Anyone looked at the signals at the back of the Shadin? Perhaps the pulses there aren't sharp enough for the JPI. Perhaps they are.... Best - Ron ________________________________ Message 2 _____________________________________ Time: 04:34:28 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Down the yellow brick road . . . --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Dee and I are launching up I35 in a few minutes headed for Oshkosh. Hope we can see many of you there. I'll be doing a forum in then tents at 2:30 on Saturday. Will be "off line" with the list until next Wednesday. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 3 _____________________________________ Time: 05:32:09 AM PST US From: "Greg Reid" Subject: AeroElectric-List: Grounding hinges in composite aircraft --> AeroElectric-List message posted by: "Greg Reid" Speaking of grounding... I've seen some recommendations that in composite aircraft, each of the metal hinges (for elevator, rudder, ailerons, and flaps) be connected to a ground point. Presumably this is to avoid static charge buildup. Or perhaps for some measure of lightning protection? (In a carbon-fiber aircraft, you can bet that I'll not be anywhere near the stuff!) Well, how important is this hinge grounding, really? You see, I neglected to do so for my empennage, and now that it's all closed out, it would be very difficult to get ground wires back there. My two COM, NAV, and ELT antennas are copper-foil inside the fiberglass VS and HS respectively. Will I have static problems with communications? Will traditional static wicks suffice to bleed that off? (The elevator and rudder skins are carbon-fiber.) My wings aren't closed out yet, so I can easily run ground wires to the aileron hinges. I have slotted flaps, with large phenolic pivot points; no metal there except for the pivot bolts. The VS and HS are fiberglass (to allow for the antennae inside), but the rest of the plane is all carbon-fiber, which I know conducts electricity to some extent.** Need I run a ground to the carbon-fiber flap and/or aileron skins too? Thanks, Greg ** I was working on mounting my pitot tube on the underside of the wings one day, and kept feeling a "tickle" in my forearm, that I feared was the start of an allergic reaction to the epoxy -- until I finally realized that it was a mild electric shock! I had an oooold jigsaw resting in one of the wing fuel bays, plugged in (apparently backwards), and its metal case was leaking 120V to the inside fuel bay skin (haven't yet Jeffco'd the bays), electrifying the entire carbon skin. The jigsaw went into the trash that day.