VAF Forums - Electrical help needed

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- - Electrical help needed (https://vansairforce.net/community/showthread.php?t=186458)

Quote:

Originally Posted by 10builder (Post 1459268)

Earl,

In one of your other posts you mentioned that you were receiving guidance from EAA1441 members. Maybe that would be a great place to start?

https://vansairforce.net/community/s...6&postcount=14

It is a small chapter with no technical counselor available. And nobody has built an RV 14 series airplane. The suggested battery came from a 1441 member, but it is being shot down here. We are all doing our best with what we have.

Quote:

Originally Posted by johnbright (Post 1459284)

FYI:

Latest Aeroelectric Connection book free PDFs are at http://www.aeroelectric.com/Books/Connection/

Latest revs of Z dwgs are in the folder called "Adobe_Architecture_PDFs/" at http://www.aeroelectric.com/PPS/ There are updates since the book came out.

Bob Nuckolls and others answer questions on the Aeroelectric List hosted by Matronics.
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Thank you. I began reading about a bussbar last night and will also read Aeroelectric's words on them too.

Are most builders using copper for the bussbar? Is it easiest to run it along the bottom of the instrument panel, along the length of the panel going across? Do I need to worry about welding the screws to the bussbar if the correct metal isn't used for the screws? If so, what is the ideal metal for the screws?

Hi Earl,
Sounds like you are trying to get it completed without any personal hands on help. These questions really cannot be answered appropriately on here as we don’t know what you are working with as far as materials, tools and any modifications that have been done to the airframe at this point. I HIGHLY suggest you get someone on board as a mentor or another partner to help you finish it up. If there are no EAA techs available then you could always call around and find a experimental friendly AP to come have a look. My 2 cents, be safe

Quote:

Originally Posted by Earl Findlay (Post 1459296)

... My last RV had problems with warm starts due to not having enough power in the battery. It would die if you turned the prop over very much at all. The primary cause was the small battery, and my fix is a battery with higher amperage ability.

Sounds like a wiring problem to me.

Gee, Bob Nuckolls says in chapter 5 on grounding: "If I had my fondest wish for ultimate performance in an aircraft electrical system, the battery, starter and alternator would all be within 1 foot of each other! Interestingly enough, Van's RV series airplanes come closer to that goal than most kitplanes. RV batteries are... with starter and alternator just an engine length away."

Ref also chapter 2 on batteries... paragraph heading "Engine Cranking".
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Earl,

There appears to be several within a 50 mile range of your zip code:

https://www.eaa.org/eaa/aircraft-bui...ical-counselor

I found that the EAA Sportair Workshop for electrical helped me, though they are paused for COVID. This workshop is 2-days long, and the video in the link illustrates the hands on training they provide.
https://www.eaa.org/Shop/SAW/Worksho...stems_avionics

EAA's hints for homebuilders videos viewed online are free to EAA members:
https://www.eaa.org/videos/hints-for-homebuilders

SteinAir has some helpful videos on wiring techniques:
https://www.youtube.com/playlist?lis...Hqdp8lReIJ0XBw

Besides the RV-14 plans there are other basic wiring plans available from Van's in the OP drawings, like OP-10, OP-12, OP-30, OP-31. Even though they are for other airframes the concepts should help.

In addition to those resources, most electronics vendors, for the major panel electronics, have detailed installation manuals for their equipment.

Dave

82 pounds? That's about 3 times the weight of the battery in my car, and my car needs enough juice to start a V-10 engine.

That's 12 pounds more than my Field Labrador Retriever.

I'm planning to use an Earth-X battery in mine - and I will have the 6 cylinder -540. I think the -900 weighs about 5 pounds.

Quote:

Originally Posted by Earl Findlay (Post 1459296)

Can you suggest a battery with the same cold cranking amps but weighs less? My last RV had problems with warm starts due to not having enough power in the battery. It would die if you turned the prop over very much at all. The primary cause was the small battery, and my fix is a battery with higher amperage ability.

The plans for the RV-14 are not that easy to read. They are single pages with part numbers and measurements on them but I am having a hard time turning those things into reality. They are not 3D. Up to this point, Hal was reading and interpreting the plans and I would do as he instructed. But I have lost Hal.

I did not know that the kit included wiring harnesses for the avionics and switches. I have been working off of the assumption that those are custom to the builder and therefore not included in the kit. Can you point me to a part number or something I can use to find the harnesses?

Earl:

As you can see from my signature, I built and flew an RV-14A. My recommendation remains the same: use the standard battery/tray and wiring for battery/starter. They work just fine. Van's supplies the basic wiring in the kit and includes mounting points for master contactor and starter relays as well, along with very good wiring instructions/diagrams.

I found the RV-14 plans to be exemplary and not at all difficult to read/understand, and I'm not at all sure what you mean by saying "not in 3D", since many of the plan drawings include perspective that is indeed 3 dimensional.

In another thread regarding your rather extreme claim (and pride in same) of exceeding VNE in your airplane, a poster suggested a safety stand-down. I suggest the same for you as a builder, as others have said. Before continuing building your airplane you need to build a basic understanding of aircraft structure and safety as it relates to aircraft structural design and integrity. Not an engineering degree but enough to understand why it might be a very bad idea to mount something very heavy inside aircraft structure not designed for the weight. Are you aware that not only would an 82 pound battery mounted below the baggage floor virtually take up all the weight allowed in that area, you would have no way to access it in the future (the baggage floor is RIVETED to the baggage ribs!) AND you would be mounting it on structure (external aircraft skin) not intended to bear the weight? (This assumes you could somehow fit this battery between the baggage ribs, floor, and fuselage skin).

Regarding your other questions - I will make no suggestions in that regard. You need to walk before you run. Get the knowledge and skills you need, and appropriate assistance from someone who has the same, before proceeding with building an airplane. Learn how to read and interpret the plans. Learn the basics before moving on to something like electrical design and installation. You don't get extra chances to do it right.