Fergs home grown battery switches and fat CCA inside copper pipe.

Copper pipe conduit.

rparigoris — Mon, 09 Aug 2010 07:48:47 +0000

Subject: Re: AeroElectric-List: Firewall Prnetration Question
From: "Robert L. Nuckolls, III"
Date: Mon, August 9, 2010 1:39 am
To: aeroelectric-list@matronics.com

At 02:20 PM 8/8/2010, you wrote:
>Good Afternoon Eric,
>
>Seems to me I remember 'Lectric Bob recommending something similar
>many moons ago. As I recall, he recommended a thin wall copper
>tubing with all those wires inside it and using the copper tube as
>the ground. Don't think he recommended fuel lines be included though!
>
>Anyone else remember that idea!

Sure. The first few of the Rutan pushers I was
involved with experimented with a copper tube
conduit and ground system that ran from nose mounted battery
to the fire wall.

Emacs!

There were a few airplanes built this way but it proved to
be a lot of work with little benefit. I took the suggestion
out of later revisions to the 'Connection.

Bob . . .

Ferg wiring 4

rparigoris — Fri, 16 Apr 2010 18:26:14 +0000

Ferg wiring 3

rparigoris — Thu, 10 Jun 2010 15:28:58 +0000

Cheers,
Per my message same subject sent late 08JUNÂ¡Â¯10 (Canada) wherein I
promised backup calcs for aft battery cabling -
These are my calcs for using household copper tubing as container and
ground return for both aft-cited batteries. I wanted to know if I was in
the Â¡Â®ballparkÂ¡Â¯ for amp-carrying capacity. I suggest following it through
if you plan similar as a phone-call or doorbell might have interrupted the
incredibly complex math. AS for European/Brit equivalents, caveat emptor.
Apologies to most US types but calcÂ¡Â¯ed in mm for greater accuracy(?):

COPPER TUBING - Â¨Ã¶Â¡Â± x 96Â¡Â± - TYPE Â¡Â®MÂ¡Â¯ - CURRENT EQUIVALENT

Method #1 - Cross-sectional area
(1) OD=D1=0.624Â¡Â±
(2) r1=D1/2=.312Â¡Â±=7.9248mm.
(3) A1=197.29956 mm2
(4) ID = 0.570Â¡Â±
(5) r2 = D2/2 = .285Â¡Â± = 7.239mm
(6) A2 = 164.62912 mm2
(7) A3 = A1-A2 = 197.29956mm2 - 164.62912 mm2 = 32.67044 mm2
(8) D3 = (Â¡Ã®A3/Â¬Â±)x2 = 6.449599mm
(9) According to POCKET REF manual (Sequoia Publishing, Colorado),
page 113 (or p.810 of the Handbook of Applied
Mathematics), the diameter
in millimetres of AWG2 is 6.544 mm. Therefore the
current-carrying capacity of thin-wall copper tubing is roughly
equivalent to AWG2, which for type T or TW gives an Ampacity of just under
110A at 40deg C. Two tubes electrically-attached should carry the
equivalent of AWG000 cable.
Since this is the design for battery contacts
used, the ground return capabilities satisfy electrical loads very well.

Method #2 - Weight per 1000 feet

(1) Measured weight of tube sample gives equivalent of 87.1 gm/ft
(2) This is equal to 87,100 gm per 1000ft
(3) 87100 gm = 87100 x 0,0022 = 191.62 lb/1000ft
(4) Referring to the reference manual in item (9) above, this gives an
AWG
equivalent to just 4% under AWG2, or about
110A, to 40deg C.
(5) See 2nd paragraph, item (9) above for double tubing.

Both these methods are in general agreement
as to sizing.

Cheers, Ferg
PS: I used #4CCA from Perihelion, with double layer of heatshrink for
security in pipe plus electrical tube end protectors on entry/exit. The
tubing exceeded the CCA capacities.

Ferg wiring 2

rparigoris — Sat, 17 Apr 2010 00:29:50 +0000

Ferg said he purchased striped heat shrink tubing from UK.
Here is at least one UK supplier:
http://www.finishrink.com/general-purpose-heat-shrink-tubing.html
And a Chimna Mfg.:
http://www.made-in-china.com/showroom/cjds888/product-detailgeFxWLRYazVP/China-Yellow-amp-Green-Stripe-Heat-Shrink-Tubing-YGDRS-1-.html
Y10-04-16

Ferg wiring 1

rparigoris — Fri, 16 Apr 2010 18:25:36 +0000

Battery cutoff switches 2.

rparigoris — Thu, 18 Feb 2010 20:20:14 +0000

This has information on spring/ball plungers.
Y10-02-18

Battery switch board.

rparigoris — Thu, 18 Feb 2010 20:21:09 +0000

Just some info Ferg included in an E-Mail:
"Did I say that Jenny has announced that the fuselage must be out of the spare bedroom by 30JUN2010 or Iâ€™ll be a bachelor on Â½-pay by 01JUL2010?
It HAS been 13 years!"
Y10-02-14

Battery Switch operation.

rparigoris — Thu, 18 Feb 2010 20:20:41 +0000

"Basically the controls are just by my left wrist in
the left seat, spring-loaded to go aft. Aft is OFF. The control knobs sit in
slots, and will spring aft if not in the Power-On slot (or if the cable
snaps, etc.) The cables snake aft to the Switch Board which holds the
switches in the â€˜fuselage behind the second bulkhead â€“ see above), The
switches take the battery(s) power and deliver to the firewall port side via
1/2inch copper pipe with CCA#4 cable. I hope that makes it a bit clearer â€“
sorry for all the Mbits."
Y10-02-14

Battery cutoff switches 1.

rparigoris — Thu, 18 Feb 2010 20:19:16 +0000

"GENERAL NOTES:
THE WHOLE PURPOSE IN PRODUCING THIS ITEM WAS TO THWART THE NEED FOR CONTACTORS, MOST OF WHICH REQUIRE UPWARDS OF 1 AMPERE TO REMAIN CONNECTED. 4 CONTACTORS TO STAY CONNECTED FOR THE LENGTH OF THE FLIGHT WAS EXCESSIVE IN VIEW OF EXPECTED NEEDS, SO A MECHANICAL ALT-ERNATIVE WAS DEVISED.
ONE EXAMPLE IS THE MASTER SWITCH WHICH IS A RACING CAR CUTOFF SWITCH OPERATED BY A REPLACEMENT â€˜KEYâ€™ WHICH PENETRATES THE INSTRUMENT PANEL FOR 11 INCHES AND IS INTERNAL PANEL-MOUNTED.
BELOW IS THE OTHER EXAMPLE. FOLLOWING THE SUGGESTION OF BOB NUCKOLLS, A SLIDING ELEMENT PROVIDES ON/OFF CONTACT WITH TWO BRASS POSTS. THE RESULT IS ABOUT EQUAL IN CONTACT RESISTANCE TO THE USUAL COMMERCIAL CONTACTOR. DIMENSIONS ARE NOMINAL AND DEPEND ON EXPECTED LOADS AND DURATION. IN MY CASE, THE LINES ARE ERIC JONES CCA#4 CABLE FROM BATTERY TO FIREWALL FORWARD POSTS."

I would like to beg a boon to give Bob Nuckolls some credit for the initial design? I complained to him about high running current in contactors and he sketched the basic idea, so itâ€™s really his baby I think. I have built several of these before settling on one model, but some have 1/4inch posts and some 5/16"

Y10-02-14