What are people using for master buss bars in homebuilts? It will have a
comm unit, transponder, and encoder plus a few instrumets. Day VFR only. I
have a 15amp alternator.

Any suggestions?

Charlie.

"ccwillwerth" > wrote in message
...
> What are people using for master buss bars in homebuilts? It will have a
> comm unit, transponder, and encoder plus a few instrumets. Day VFR only.
> I have a 15amp alternator.
>
> Any suggestions?
>
> Charlie.

You'll get many opinions, but one inexpensive and functional approach is to
go to your local auto parts emporium and get a blade type fuse holder to
use. Mount the fuse block behind the panel. Hook the big, hot wire to the
"in" side of the fuse block, and feed individual circuits through properly
sized fuses on the fuse holder.

KB

ccwillwerth wrote:
> What are people using for master buss bars in homebuilts? It will have a
> comm unit, transponder, and encoder plus a few instrumets. Day VFR only. I
> have a 15amp alternator.


I don't remember exact details, but we used a thick copper strip to
which the CB switches attached directly.

ccwillwerth wrote:
> What are people using for master buss bars in homebuilts? It will have a
> comm unit, transponder, and encoder plus a few instrumets. Day VFR only. I
> have a 15amp alternator.
>
> Any suggestions?
>
> Charlie.
Hi, Charlie! Get some 1/4" or 3/8" copper tube at your local hardware
store. Flatten it with a hammer, and drill a series of holes in it for
1" #6 or #8 screws. Mount the screws through the holes, using internal
tooth lockwashers under the screw and under the nut. Voila! Busbar! Now
here's something else you can do. Mount two busbars in parallel with a
terminal strip in between. Make the top bus the (+) bus and the bottom
one the (-) bus. From the (+) bus and the terminal strip in the center
between the two busses, run a twisted pair to your circuit breaker.
Then run a twisted pair from the terminal strip and the (-) bus to the
load. All of the load current from the CB to the load will be flowing
in opposite directions in the pair, giving excellent EMI cancellation.
This is especially important in plastic and wood airplanes to minimize
radio interference. Remember: every load requires two conducters, one
to take the electrons (holes) from the source to the load, and one to
return them back to the source! Another thing to do is mount a 14V LED
immediately above each CB, wired across the CB. That way, if the CB
opens, the LED above it will be on, except in an intermittent load,
such as the flap actuator. There, if the CB is open, the LED will glow
when the flap is actuated. Paul

You may want to check your local boat supply company like
www.cabelas.com/

May I suggest you visit this site: http://www.aeroelectric.com/

Dig around there and you will find out just about everything you need to
know about aircraft electrical systems.

You might also visit the "AeroElectric-List at http://forums.matronics.com

All of the people there are quite helpful...



"ccwillwerth" > wrote in message
...
> What are people using for master buss bars in homebuilts? It will have a
> comm unit, transponder, and encoder plus a few instrumets. Day VFR only.
I
> have a 15amp alternator.
>
> Any suggestions?
>
> Charlie.
>
>

For a very light load like this, may I suggest that you look at the Radio
Shack 274-656 through 274-670 with the 274-650 jumper strip. All this talk
of heavy brass strips and such for a few amps of current is using a howitzer
on a housefly.

There are Mouser and Digikey equivalents if your local Shack has been
castrated.

Jim



> "ccwillwerth" > wrote in message
> ...
>> What are people using for master buss bars in homebuilts? It will have a
>> comm unit, transponder, and encoder plus a few instrumets. Day VFR only.
> I
>> have a 15amp alternator.
>>
>> Any suggestions?
>>
>> Charlie.

ccwillwerth wrote:
> What are people using for master buss bars in homebuilts? It will have a
> comm unit, transponder, and encoder plus a few instrumets. Day VFR only. I
> have a 15amp alternator.
>
> Any suggestions?
>
> Charlie.
>
>
Aircraft Spruce has a kit that you can just cut off what
you need. I used that and then powered it thru the Battery (Master)
Relay with a 30a breaker in the line.

karel wrote:
> "RST Engineering" > schreef in bericht
> .. .
>
>>For a very light load like this, may I suggest that you look at the Radio
>>Shack 274-656 through 274-670 with the 274-650 jumper strip. All this
>>talk of heavy brass strips and such for a few amps of current is using a
>>howitzer on a housefly.
>
>
> Again I tend to agree with Master Jim.
> Though I went & bought a full length of heavy brass strip for my camper,
> the best part is still out somewhere,
> any homebuilder near Flanders is welcome to take part of it!
> But it was bought for currents up to a 100 Amps, no comparison.
>
>

Check you local hobby store and see if the sell brass. I have used
brass strips from the "brass centers." I think 3/8" wide by 1/16" thick
would cover just about anything you want to power. I went with 1/8"
thick simply because it's easier to drill.

Dan, U.S. Air Force, retired

Brass has substantially less conductivity than copper. Aluminum has
less conductivity than copper, but has twice the conductivity per pound.

Conductivity for a hunk of metal 62 mils thick by quarter inch wide by a
foot long where you measure resistance in the micro-ohms means absolutely
nothing -- copper, brass, or aluminum. On the other hand, corrosion means a
lot -- like steel hardware on aluminum, no matter how good the plating on
the steel.

Jim


"ELIPPSE" > wrote in message
oups.com...
> Brass has substantially less conductivity than copper. Aluminum has
> less conductivity than copper, but has twice the conductivity per pound.
>

"RST Engineering" > wrote in message
...
> Conductivity for a hunk of metal 62 mils thick by quarter inch wide by a
> foot long where you measure resistance in the micro-ohms means absolutely
> nothing -- copper, brass, or aluminum. On the other hand, corrosion means
> a lot -- like steel hardware on aluminum, no matter how good the plating
> on the steel.
\
All good points. So, what is it that you are trying to say , in regards to
which material should be used, and which to stay away from?
--
Jim in NC

I said that I much prefer what is called a barrier strip terminal block, and
whether you get it at The Shack, Mouser, Digikey, etc. is immaterial.

However, if you are going to roll your own, I prefer brass, as it corrodes a
lot less than either copper or aluminum.

Jim


"Morgans" > wrote in message
...
>
> "RST Engineering" > wrote in message
> ...
>> Conductivity for a hunk of metal 62 mils thick by quarter inch wide by a
>> foot long where you measure resistance in the micro-ohms means absolutely
>> nothing -- copper, brass, or aluminum. On the other hand, corrosion
>> means a lot -- like steel hardware on aluminum, no matter how good the
>> plating on the steel.
> \
> All good points. So, what is it that you are trying to say , in regards
> to which material should be used, and which to stay away from?
> --
> Jim in NC

Morgans wrote:
>
> "RST Engineering" > wrote in message
> ...
>
>> Conductivity for a hunk of metal 62 mils thick by quarter inch wide by
>> a foot long where you measure resistance in the micro-ohms means
>> absolutely nothing -- copper, brass, or aluminum. On the other hand,
>> corrosion means a lot -- like steel hardware on aluminum, no matter
>> how good the plating on the steel.
>
> \
> All good points. So, what is it that you are trying to say , in regards
> to which material should be used, and which to stay away from?

I took what he was saying to be that the difference in conductivity
between the materials mentioned for the size piece in question isn't a
factor worth worrying about. Compatibility with the connectors is much
more important as any galvanic corrosion between the connector and the
buss bar will cause substantially more resistance than will the
difference in buss bar material.

So pick the buss bar material which is most compatible with your
connector material.


Matt

"RST Engineering" > wrote in message
.. .
>I said that I much prefer what is called a barrier strip terminal block,
>and whether you get it at The Shack, Mouser, Digikey, etc. is immaterial.
>
> However, if you are going to roll your own, I prefer brass, as it corrodes
> a lot less than either copper or aluminum.
>

I take, then, the terminal block (if it is what I am thinking of) will
require individual wires with terminals crimped onto them, to make the
connection with the individual breakers, or fuses?
--
Jim in NC

RST Engineering wrote:
> Conductivity for a hunk of metal 62 mils thick by quarter inch wide by a
> foot long where you measure resistance in the micro-ohms means absolutely
> nothing -- copper, brass, or aluminum. On the other hand, corrosion means a
> lot -- like steel hardware on aluminum, no matter how good the plating on
> the steel.
>
> Jim
>
>
> "ELIPPSE" > wrote in message
> oups.com...
> > Brass has substantially less conductivity than copper. Aluminum has
> > less conductivity than copper, but has twice the conductivity per pound.
> >
All power substations use aluminum bar conductors. The trick with
aluminum conductors is that you must apply something like NO-OXID or
Vaseline to the conductor, abraid it with steel wool or crocus cloth,
then, leaving the grease in place, fasten the conductors together using
Belleville washers. Aluminum starts to oxidize immediately when
cleaned, so the grease seals the surface from air. The spring washers
apply the 1500 psi contact force that assures very low resistance, and
also allows for the difference in thermal expansion rates between the
steel fasteners and the aluminum. For instance, 1/8" X 1" 6063-T5
aluminum, such as in the Macklinburg-Duncan display at your hardware
store, has the same conductivity as AWG 0-1 OFHC copper but at half the
weight and much less cost. That's how I made my two 8' battery
conductors in my Lancair that go from the battery in the baggage
compartment to the engine. This method was given us by Alcoa in putting
in the ground grid for our radar and computers in the Atlas Guidance
system. Rocket Science!

"ELIPPSE" > wrote

> For instance, 1/8" X 1" 6063-T5
> aluminum, such as in the Macklinburg-Duncan display at your hardware
> store, has the same conductivity as AWG 0-1 OFHC copper but at half the
> weight and much less cost. That's how I made my two 8' battery
> conductors in my Lancair that go from the battery in the baggage
> compartment to the engine.

What did you use for insulation, on the positive bar?
--
Jim in NC

Hi, Jim! First off, remember its a fiberglass plane. I ran one bar down
each side of the fuselage and put one layer of fiberglass over each.
Another way would be to put in one bar, fiberglass over it, put the
second conductor over top of the first, then fiberglass over that. That
construction yields a good-quality distributed-capacitance for
transient suppression, and the two close-together conductors give good
EMI cancellation. Paul

"ELIPPSE" > wrote

> Hi, Jim! First off, remember its a fiberglass plane. I ran one bar down
> each side of the fuselage and put one layer of fiberglass over each.
\\
Good idea. I'm not a glass kind of guy, so I might not have thought of
that.
--
Jim in NC