SonexBuilders.net

Today's "invention":

Through the firewall ground terminal complete with cockpit ground bus bar.

The plywood in the picture is the firewall.
When I get closer to needing/ using it, I will drill and tap several holes for 8-32 hardware.

The fun part was using my new "scotchbrite" belts on my 1x42 bench top belt sander. VERY happy with them.

Looks good! I'd recommend using lock nuts on the outsides.

Bryan Cotton wrote:Looks good! I'd recommend using lock nuts on the outsides.

I have internal star lock washers on there. Off to the hardware store soon to complete this little project.

Drilled and tapped! Added ring terminals to verify my spacing and thought process. Nine ground connections shown. Can easily be 18 by putting the ring terminal back to back. AC 43.13-1B 11-98(f) allows 36.

Very neat. Very clean.

Success!!

If you double up i would change the approach direction so the top comes in over the top and the bottom comes in from the bottom that will make it a little cleaner with double stacking.

lakespookie wrote:If you double up i would change the approach direction so the top comes in over the top and the bottom comes in from the bottom that will make it a little cleaner with double stacking.

Good idea!
I've actually come up with multiple solutions if I need to double up. In reality, at least for my plane, they won't be needed.

I apologise in advance for being "picky" -

First - Great idea! Probably don't need such a heavy bolt.

Why not use brass/copper through bolt & nuts, for least electrical resistance, minimised potential for electrolysis and I agree with Brian, use a lock nut for best anti vibration security.

I had a piece of copper I was going to use, and that stuff is heavy! Aluminum has been good enough for me. Threads in aluminum can be sketchy so I use a nut on the back side.

Skippydiesel wrote:I apologise in advance for being "picky" -

First - Great idea! Probably don't need such a heavy bolt.

Why not use brass/copper through bolt & nuts, for least electrical resistance, minimised potential for electrolysis and I agree with Brian, use a lock nut for best anti vibration security.

Not "picky" at all. I always appreciate a second set of eyes. That's why i posted this. Otherwise I would have tunnel vision.

This is my first iteration and basically used what I had on hand. I used brass because (1) I had it, and (2) most all of the commercial bus bars I have seen are brass. In hindsight (always 20/20), the 3/8" stud IS too big. I could easily use 5/16". And I do have tons of 5/16" threaded rod. And it can, and will be, much shorter.

And I do agree with Bryan that it should be a lock nut, and it will be.

Bryan Cotton wrote:I had a piece of copper I was going to use, and that stuff is heavy! Aluminum has been good enough for me. Threads in aluminum can be sketchy so I use a nut on the back side.

I could easily use aluminum, and probably should. Afterall, if I used the airframe as ground it would obviously be aluminum.

Appreciate the comments. Helps to refine my project. And prevents tunnel vision.