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  #31  
Old 04-30-2021, 10:25 AM
agent4573 agent4573 is offline
 
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Quote:
Originally Posted by bjdecker View Post
Some of us used copper pipe from Home Depot, flattened it, and fashioned our own bars...

All other things being equal -- you should be fine with a .138" bar...

*edit -- the math ---*

The reason? They (Van's) are trying to create an equivalent conductor as 2ga wire; 2ga wire has a diameter of ~.258", thus a cross sectioned area of ~.052in.sq. A single piece of copper 1/2" wide and .063" thick has a cross section of .0315in.sq., doubling that yields .063in.sq --- just a hair more than 2ga wire.

Wall thickness for 1" copper tubing is between .035" and .065"
This is all true, but for completeness, this equivalency only works for DC systems. If you're pushing AC through the conductor, a stranded 2 gauge cable will conduct better than solid copper with the same cross section area.

https://en.wikipedia.org/wiki/Skin_effect
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  #32  
Old 04-30-2021, 01:55 PM
BobRV7 BobRV7 is offline
 
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Thanks Brian for correcting me, Got my OP and DWG mixed up. That would make a difference
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  #33  
Old 05-10-2021, 12:39 PM
smithflys23 smithflys23 is offline
 
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Originally Posted by rvbuilder2002 View Post
Most all Lyc engine cases have a hole in the case web that is directly aft of the base of the dip stick tube. This hole is used for no purpose on an RV so it makes it a great ground cable attach point (just be sure to fully remove an paint / primer down to bare metal for a good electrical bond).
Is this the spot you were referring too?

I'm not sure why the pics attached sideways.

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  #34  
Old 05-10-2021, 12:43 PM
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bjdecker bjdecker is offline
 
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Quote:
Originally Posted by smithflys23 View Post
Is this the spot you were referring too?

I'm not sure why the pics attached sideways.

Attachment 11403

Attachment 11404
Yup, that's one of them...
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  #35  
Old 05-10-2021, 02:44 PM
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Quote:
Originally Posted by smithflys23 View Post
Is this the spot you were referring too?

I'm not sure why the pics attached sideways.

Attachment 11403

Attachment 11404
That's what I used.
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  #36  
Old 05-10-2021, 03:27 PM
smithflys23 smithflys23 is offline
 
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Originally Posted by bjdecker View Post
Yup, that's one of them...
Ok, now that We’ve established A good place to ground the engine case, what about the firewall ground? I don’t have a dedicated ground bar on the firewall. Mine is grounded on the engine mount, which was decided to be less than ideal.

What about using the rudder pedal anchor point?

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  #37  
Old 05-10-2021, 03:39 PM
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Quote:
Originally Posted by smithflys23 View Post
Ok, now that We’ve established A good place to ground the engine case, what about the firewall ground? I don’t have a dedicated ground bar on the firewall. Mine is grounded on the engine mount, which was decided to be less than ideal.

What about using the rudder pedal anchor point?

Attachment 11415
Yes, provided that 100% of the 2GA wire lug is in contact with the firewall, or that metal strap...

See green circle...Can you drill out this rivet and put an AN4 or AN5 bolt in there?
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Last edited by bjdecker : 05-10-2021 at 03:49 PM. Reason: added picture...
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  #38  
Old 05-10-2021, 03:45 PM
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Carl Froehlich Carl Froehlich is online now
 
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Quote:
Originally Posted by smithflys23 View Post
What about using the rudder pedal anchor point?

Attachment 11415
I would not consider this as viable. Ground the engine to the same place you have the battery(s) grounded on the firewall. If the battery(s) are not grounded on the firewall, then I assume you have a rear mounted battery and are using a nearby airframe ground. Is this correct? If so, then I recommend a simple bolt on the firewall, that captures both the SS firewall as well as a supporting firewall angle. On the cabin side run a cable from this same bolt to whatever you are using for your common panel ground.

Side note - for my RV-10 and RV-8 rear mounted batteries I did belt and suspenders - a local ground and a ground wire to the common firewall ground.

Carl
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  #39  
Old 05-10-2021, 03:57 PM
smithflys23 smithflys23 is offline
 
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Quote:
Originally Posted by bjdecker View Post
See green circle...Can you drill out this rivet and put an AN4 or AN5 bolt in there?
It’s a flying airplane, so it would be a pain, but possible.
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  #40  
Old 05-10-2021, 04:00 PM
smithflys23 smithflys23 is offline
 
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Quote:
Originally Posted by Carl Froehlich View Post
If the battery(s) are not grounded on the firewall, then I assume you have a rear mounted battery and are using a nearby airframe ground. Is this correct?
Correct.
Actually, I have to fix the rear battery ground as well. One of the “Pros” ground the battery on the frame of the battery box, instead of on the airframe itself.
Thanks, Carl.
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