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Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 11:07 am
by BobDz
Bryan Cotton wrote:As bad as steel looks on that list, consider that resistance/conductivity is also a function of cross section area and length. The length is very small, and the cross section area is large. It really won't matter what you select.


Very true. I am way over thinking this!

Right now I'm thinking of 5/16 brass threaded rod (toilet flange bolt) with a 4" piece of 1/8 × 1 aluminum angle (scrap from longeron). Using the angle will offer many, probably too many, possible terminal locations. Should be the neatest and coolest iteration yet.

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 11:17 am
by BobDz
"If you're going to make it, make it beautiful!" Bob Emser

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 12:31 pm
by BobDz
For illustration purposes, my original brass bus bar with 18 terminals neatly installed

Add a locknut to the backside, and you get 18 more.

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 2:50 pm
by BobDz
My "final" answer (?)

I will have the correct lock washers for the final install.

13 holes will accommodate a maximum of 52 terminals.
1/16 ×1" angle is much lighter. The 5/16 brass stud will accept the 2/0 cable(s) on the engine side.

Time for lunch!

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 3:37 pm
by BobDz
And no, the irony of doing a distraction project that required drilling and deburring because I didn't feel like working on the plane doing drilling and deburring, is not lost on me...

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 9:05 pm
by Skippydiesel
On my last aircraft (composite airframe) I installed a length of aluminium angle (from faulty memory 25 x 25 x 2mm) behind the instrument panel, from one side of the fuselage to the other.

I pop riveted a top/bottom row of male spade connectors (with a dab of electrolytic grease) ie two connectors per rivet, at strategic points, corresponding to instruments in the panel.

Both ends of the angle were securely connected into the aircrafts earth/ground (-) return ring circuit (including external anti static fuel terminal).

The aluminium angle earth buss facilitated short cable runs from each instrument and provided an excellent low resistance earth return.

It also acted as a handy support for the cable loom & other loose "stuff" behind the panel.

Some may frown on the use of spade connectors however I have always found they work well, when correctly installed. They are a low weight, much less fiddly solution, compared with a screw/nut fixing (I always drop either the nut and or washers, into the depths of the aircraft, taking much time consuming/frustrated searching to find).

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 9:17 pm
by BobDz
Skippydiesel

I certainly see the use of having the angle completely across. Lots of uses for that. And you would probably have the shortest ground wires.