Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 02-09-2019, 06:04 PM
Nova RV Nova RV is offline
Join Date: Aug 2015
Location: Leesburg, VA
Posts: 439

I would make sure the bus sits on the firewall as flush as possible to maximize the contact area between the bus and the firewall. Just my opinion, I'm sure one of the engineers here can give a good electrical explanation either pro or con.
Chris Moon
Leesburg, VA

CFI-I ASMEL, ATP, B-1900, A319/320, B-757/767, B-737, Flight Engineer-Turbojet

RV-14A kit # 140243 (flying as of 11/18)
VAF 2018 and 2019 paid
Reply With Quote
Old 02-09-2019, 06:25 PM
Mich48041 Mich48041 is offline
Join Date: Apr 2008
Location: Riley TWP MI
Posts: 2,990

Does this make any sense? Or is it a stupid idea?
Not a stupid idea. It shows ingenuity.
But I would not do it because a steel bolt is a poor electrical conductor.
Although a short steel bolt might not offer much resistance.
It will not look good.
How about replacing the nutplate with a nut and use a brass bolt?
Joe Gores
RV-12 Flying
Reply With Quote
Old 02-09-2019, 08:11 PM
rv7charlie rv7charlie is offline
Join Date: May 2006
Location: Pocahontas MS
Posts: 3,882

I use the technique you describe for holding prop balance weights on the inside of my spinner bulkhead. But, and it's a big but, I have access to both ends of the fastener.

If you use the technique on a firewall bolt, you lose control over the torque on the bolt itself. Any tightening torque you apply to a nut on the back side of a nutplate will be loosening torque on the bolt.

If you're serious about doing it, I'd look at the cross section resistance of a copper (or more realistically, brass) bolt vs steel, as others mentioned.

Reply With Quote
Old 02-10-2019, 08:19 AM
Raymo's Avatar
Raymo Raymo is offline
Join Date: Nov 2014
Location: Richmond Hill, GA (KLHW)
Posts: 2,149

Originally Posted by Stockmanreef View Post

what is that piece of green material that lines the lightning hole in the picture? I would like to line a couple of lightning holes in the bulkheads.


This link to ACS will get you to them.
RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, Dual PMags, Vetterman Trombone Exh, SkyTech starter, BandC Alt (PP failed after 226 hrs)
Catto 3 blade NLE, FlightLines Interior, James cowl, plenum & intake, Anti-Splat -14 seat mod and nose gear support
All lines by TSFlightLines (aka Hoser)
Reply With Quote
Old 02-10-2019, 11:49 AM
mikesierra mikesierra is offline
Join Date: Sep 2016
Location: Cincinnati
Posts: 18

Another economical source for grommet edging;

RV-10, 3 years in, end in sight, on a good day

Dues paid
Reply With Quote
Old 02-10-2019, 11:53 AM
N941WR's Avatar
N941WR N941WR is offline
Join Date: Jan 2005
Location: SC
Posts: 12,851


I put my two Forest of Tab (FoT) ground blocks on either side of the firewall and bolted through them with brass bolts. This was done so I wouldn't have any potential (pun intended) grounding issues. After the wires were installed, they were drawn back to the side so they would not interfere with removing the battery.

What surprised me was that I need more tabs aft of the firewall and only used two tabs on the forward side.

Note, the AN bolts in these pictures were replaced with brass bolts, washers, and nuts.

Forward side -- Aft Side

(Click to enlarge)
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC

Last edited by N941WR : 02-10-2019 at 11:57 AM.
Reply With Quote
Old 02-10-2019, 03:09 PM
mturnerb mturnerb is offline
Join Date: Apr 2015
Location: Ponte Vedra, FL
Posts: 1,273

Originally Posted by Stockmanreef View Post
thanks. This clears things up for the ground. What gauge wire should connect the forest of wires to the battery ground?

Now I just have to figure out how the heck to attach the G3X shunt. It appears that it is connected to the master relay via a piece of copper, then, the two terminals connect to.....

I'm assuming you're referring to the ammeter shunt. If you look at the 3rd picture on this page: you will see the shunt between the two feeds from the alternator and standby alternator, connected to the main cable that goes through the firewall to the main power relay. Vic Syracuse recommended this setup - we drew it on the firewall (photo here: and I just copied that setup. As you can see I used ANL fuses for each alternator - I used short pieces of very heavy (6 ga) wire to connect each of these to the shunt. The shunt has a tiny amount of resistance and the two wires across this resistance measure current (at least that's the way I understand it).
Turner Billingsley

RV-14A built/sold N14VB
RV-10 in progress as of May 2020

Last edited by mturnerb : 02-11-2019 at 03:17 AM.
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 05:18 AM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.