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Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 12:12 am
by daleandee
BobDz wrote:
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.


Nicely done and the more you develope it the better it gets.

FWIW I bought a grounding block from B&C Specialities (forrest of tabs) with 24 connections on it and found out that I needed more than that. Of course I have an electrically dependent airplane but I never imagined I'd need that many connections ...

Dale
3.0 Corvair/Tailwheel

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 9:33 am
by BobDz
daleandee wrote:
BobDz wrote:
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.


Nicely done and the more you develope it the better it gets.

FWIW I bought a grounding block from B&C Specialities (forrest of tabs) with 24 connections on it and found out that I needed more than that. Of course I have an electrically dependent airplane but I never imagined I'd need that many connections ...

Dale
3.0 Corvair/Tailwheel


Thanks Dale!

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 9:48 am
by Friesen5
I did something similar almost 20 years ago. It’s providing a solid ground for my Sonex. I took a photo of it yesterday, so I’ll try to attach it.

Mervin Friesen
Sonex 122

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 10:02 am
by BobDz
Friesen5 wrote:I did something similar almost 20 years ago. It’s providing a solid ground for my Sonex. I took a photo of it yesterday, so I’ll try to attach it.

Mervin Friesen
Sonex 122


That definitely is the lightest solution I have seen!

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 10:04 am
by BobDz
The things I learn in the rabbit hole.

Looks like my next iteration should be a brass stud with an aluminum bar.

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 10:37 am
by Bryan Cotton
Looks good Mervin!

Like Dale, I find that too many ends up being not enough. Two lugs per screw is really just a serving suggestion.

3/8 is massive. I wouldn't go bigger than #10, but I would support both ends with that design. Or mount it in the middle possibly.

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 10:45 am
by BobDz
Bryan Cotton wrote:Looks good Mervin!

Like Dale, I find that too many ends up being not enough. Two lugs per screw is really just a serving suggestion.

3/8 is massive. I wouldn't go bigger than #10, but I would support both ends with that design. Or mount it in the middle possibly.


I originally used 3/8" because on the engine side of the firewall there will be two 2/0 cables attached and I have 2/0 x 3/8" lugs. I also have 2/0 × 5/16" lugs. So I will downsize to 5/16.

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 10:54 am
by BobDz
But that brass angle does look tempting.

OR...

I will soon have a few scraps of 1/8 ×1 aluminum angle!!

This rabbit hole is getting deeper...

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 11:00 am
by Bryan Cotton
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.

Re: Through Firewall Gound Terminal

PostPosted: Fri Feb 23, 2024 11:04 am
by Bryan Cotton
BobDz wrote:I originally used 3/8" because on the engine side of the firewall there will be two 2/0 cables attached and I have 2/0 x 3/8" lugs. I also have 2/0 × 5/16" lugs. So I will downsize to 5/16.


2/0 is massive! The Aerovee manual specifies 6ga minimum and I think I used 4ga.