Author Topic: Move the battery????????  (Read 6155 times)

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Offline Stanford Zinger

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Move the battery????????
« on: November 14, 2011, 11:32:29 AM »
Hi Guys

My long EZ is sitting on a saw horse (the nose is anyway) I have installed the Wright electric nose gear.
Of course,  the CRANK and the battery was located in the nose....He also had 2  one kilogram weights
in the nose as ballest. Now my problem is I am starting to rewire the whole ship. Should I plan on moving the
battery and if so----where????? or do I leave it in the nose. I do have have the weight and balance
from the guy I bought the plane from.... He has passed away and I dont think its still useful

What do you think????

Regards
Stan

Offline av-mech

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Re: Move the battery????????
« Reply #1 on: November 14, 2011, 12:06:54 PM »
It's kinda difficult to say at this moment.  You need to have the whole airplane together, ready to fly, and then weigh it.  From that you must then decided if what you have done will work or maybe you need to move something. 

Now I know that's not really a useful answer at this point so.........you can compare what your weight to what the last pilot was counting his weight as (maybe he used 170 lbs or maybe he used his real weight)whatever it was it should be shown in the last CG calc.  Look at what his CG was and compare his configuration of the aircraft to what you are doing.  This should give you a general idea of what to expect with your W&B.

Arnold Holmes
N80SH
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Offline Joe Person

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Re: Move the battery????????
« Reply #2 on: November 14, 2011, 01:26:18 PM »
The only safe way to account for the changes, especially for non-builder owners, is to repeat/re-do the complete W&B procedure defined in the Long-EZ Owner's Manual.  There too much at stake to not do this, after such extensive change to the airplane.  Unless during it's entire operational life, the airplane has had a complete accounting for all W&B changes, AND, the W&B of your retrofit of the new NLG system (and whatever else you are doing) can be accurately mathematically accounted for, you should physically perform a new W&B per the Owner's Manual.  This would yield complete W&B data, and, most-importantly, re-establish the actual Min/Max front seat (pilot) weight for the particular airplane.  The original, as-built airplane had to have a W&B performed, including the Min/Max pilot weight, as part of the overall process that led to the Special Airworthiness Certificate.  Leave nothing to chance or TLAR here.

Joe Person
VariEze N79JN
Cozy #879 Under Construction
EAA Tech Counselor 4418
Bothell, WA (KPAE)

Offline Radioflyer

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Re: Move the battery????????
« Reply #3 on: November 15, 2011, 11:17:08 AM »
I own a LongEz with an O-320 and if I were to tackle my battery and wiring system in its entirety, I would take the battery out of the nose and mount it nearer to the engine. Probably, just behind the passenger's head or below his/her thigh support. With this configuration I see at least two significant advantages. 1)Weight and length (resistance) of thick cable runs to the engine is minimized. 2)It helps to keep the electrically noisy cables away from noise-sensitive wiring to the avionics. It also puts the battery in a warmer location than the notoriously cold nose, for greater performance. By the way, I use an Odyssey PC625 battery which is considerably lighter than the standard Gill25 battery originally used, and can be mounted in any orientation. I'm pretty sure I could get away with an even smaller battery, if I were so inclined.

The battery in the nose was good for weight and balance when the plane was originally designed and built to plans. However, considering the customizations in most planes, with electric retract, more heavily instrumented panels, lighter alternators, starters (making heavier O-320s more practical), lighter cowlings, disuse of heavier aluminum spinners, etc., I think that even if some additional nose ballast was still required for W&B, the advantage of a more reliable electrical system is worth the penalty. Furthermore, this ballast could be smaller and placed even more forward than where the battery would fit.

You didn't say what engine you have or if you have a standard or lengthened nose section, but you will still be able to get your CG correct with the battery out of the nose. I have confidence you will do a proper W&B.

Offline Stanford Zinger

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Re: Move the battery????????
« Reply #4 on: November 15, 2011, 05:18:36 PM »
Hi
Thanks for the info  I have a Lycomine 0-235
I will plan to put it in the rear

Regards
Stan

Offline av-mech

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Re: Move the battery????????
« Reply #5 on: November 15, 2011, 06:49:25 PM »
I presume you are talking about the battery..........as the engine is supposed to be in the back! ;D
Arnold Holmes
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Offline Stanford Zinger

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Re: Move the battery????????
« Reply #6 on: November 16, 2011, 07:42:39 PM »
Hellllllllllllllllllllllllllo Arnold

You are a funny guy

Regards
Stan

Offline BruceHughes

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Re: Move the battery????????
« Reply #7 on: November 17, 2011, 12:48:00 AM »
Hi Stan

I hope you read Joe Person's email.  Read it again.

As you have an O-235, you have a faint possibility of moving the battery out of the nose.
However I believe it is EXTREMELY unlikely to get the W & B correct with the battery in the
back.

Maybe you can if you weigh 200 lb yourself.   Anyway you have to get everything finished,
then do an ACCURATE W & B.   I did mine 5 times with changes each time. 

Check with the local EAA chapter or the guys that race cars.  They may have electronic
scales as does the EAA chapter that I am in.   

We lost a Longeze at Kanab about 15 years ago due to the "battery-in-the-back" idea.   
Fortunately the guy survived.

Bruce Hughes    :)

Offline Radioflyer

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Re: Move the battery????????
« Reply #8 on: November 17, 2011, 10:01:17 AM »
If a weight and balance is properly done, the battery mass in the back can't have anything to do with a crash. Would you crash if you placed a 200 lb guy in the back seat? Come on, its common sense. Just compensate as necessary and get your CG correct. Maybe you'll wind up a few pounds heavier overall, maybe, but you will ALWAYS be able to get the proper CG, especially with the lighter O-235. But I agree, get some beam-and-balance or electronic scales and do a physical weight and balance. You need to do this no matter what you decide to do.

Offline dhanson44

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Re: Move the battery????????
« Reply #9 on: November 20, 2011, 11:45:51 AM »
Listen to Joe P. trust me you do not want to fly with aft CG in one of these planes. I made that mistake and its not fun. After any major major work on these planes its best to follow the prescess and do a WB before flight.
Dave Hanson
Built
N 440 EZ VE
N 220 EZ VE
N 440 DH SQ 2000

Offline dorr

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Re: Move the battery????????
« Reply #10 on: November 23, 2011, 12:26:57 AM »
We hold copies of Burt Rutan and Mike Melvill doing the weight and balance on an O-235 Long EZ - if you don't have the videotape, you would probably enjoy seeing it.  I doubt the battery needs to be moved unless you are over 250 lbs.

Beagle
David A.C.Orr
"Beagle"
www.canardfinder.com

Offline BruceHughes

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Re: Move the battery????????
« Reply #11 on: November 24, 2011, 12:30:17 AM »
If you decide to try moving the battery, think about this:

The battery is very heavy.   If you should crash, you stop VERY quickly.
Do you want the battery breaking away from  whatever straps hold it
down?   Are those TLAR straps or are you an engineer that can calculate
the stress?

Whatever weight advantage you get from shorter/lighter cables may be largely
eaten up by heavier structure to hold the battery.

Bruce Hughes    :)

Offline av-mech

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Re: Move the battery????????
« Reply #12 on: November 24, 2011, 06:13:30 PM »
considering that there is at least 220lbs of engine right behind the supposed battery location, the battery is not going to be the only thing relocating to the cockpit in a bad crash.  So I don't think that worrying about the battery coming loose in a crash when located on the firewall is a major concern.

I have my battery located on the aft side of the firewall and it sits in a carbon tray with 4130 tubing acting as legs that bolt to the engine mount bolts.  The tubing was slit on the end and I welded tabs on each end with a bent angle necessary to line it all up.  The tray is bolted to the tab using countersunk AN screws (with shank) and metal lock nuts.  My master and starter solenoid are also attached to this tray and the battery cables and starter cables are very short.  I have a #12 wire running up front to a 10 amp circuit breaker switch that controls the avionics.  It only takes a #20 wire running from the master and starter button to activate the solenoids in the back.  Easy Peasy Lemon Squeezy.
Arnold Holmes
N80SH
IA 2712249
EAA 519850
TC#4476
Av-Mech.com