Graham, No I meant it as writ! The original well thought
out design was conceived around a 912 and a simple prop as
I understand it. The significant extra weight of a 914 and
a wobbly prop hanging on the front might be expected to
make it relatively nose heavy. Ten pounds extra on the
p[rop probably just about accounts for my 3 lb of lead.
Regards, David
GRAHAM SINGLETON <grahamsingleton@btinternet.com> wrote:
> David,
> I suspect you meant to say "unexpectedly nose heavy" ?
> regards
> Graham
>
>
> ________________________________
> From: David Joyce <davidjoyce@doctors.org.uk>
> To: europa-list@matronics.com
> Sent: Saturday, 28 April 2012, 12:49
> Subject: Re: Europa-List: starter battery - LiFePO4
>
><davidjoyce@doctors.org.uk>
>
>
> Craig & Graham, Right from the start I planned to have
>my battery in the engine compartment, and it has worked
>very well. It sits on top of the passenger footwell with
>a one inch retaining wall around its bottom end and fixed
>with a nylon strap from the firewall over the top and
>down. that is a much simpler and lighter mounting than
>any I have seen in the rear. I have an Oddyssey 17 amp hr
>battery which has had more than enough welly to start the
>engine instantly even after a 3/12 break in the winter. I
>made no provision for cooling and it doesn't seem to have
>noticed.
> As to weight and balance I have a mono XS,
>914 and a Woodcomp SR 3000 W wobbly prop and a very well
>equipped panel (although much of this electronic rather
>than steam age!), so my plane might be expected to be
>nose heavy. I calculated what I thought was the optimum
>position for the Ready for Service C of G as what would
>allow any combination of pilot/s, fuel & luggage and came
>up with the figure of 59 ins or thereabouts (but the
>precise figure will depend on the base weight of the
>plane but I guess the optimum will be very close to this)
>To achieve that precise CoG position I found I needed a
>small, 3 lb block of lead bolted to the front of the tail
>bulkhead (accessed conveniently through the trim slots).
>I suspect I had saved most or all of 3lbs in longer
>cables and more elaborate mounting & fixing of a rear
>battery. My advice would be to assume this is wha.t you
>will do with the battery and only shift it to the much
>more inconvenient
> rear position if your plane turns out to be unexpectedly
>tail heavy.
> Regards, David Joyce, G-XSDJ
>
> GRAHAM SINGLETON <grahamsingleton@btinternet.com> wrote:
>> Craig,
>> you're right. moving the battery forward would require
>>roughly half it's weight in the tail to compensate.
>> You save the weight of the cables too. You need to
>>consider keeping the battery cool if it's in the engine
>>bay though.
>> Graham
>>
>>
>> ________________________________
>> From: craig <craigb@onthenet.com.au>
>> To: europa-list@matronics.com Sent: Saturday, 28 April
>>2012, 0:04
>> Subject: RE: Europa-List: starter battery - LiFePO4
>>
>>
>>
>> Philip
>>
>> You mentioned the issues of weight and balance, for not
>>using
>> the LiFePo battery, assuming you had the battery in the
>>rear
>> As per most builds, was the option of another half kilo
>>of ballast
>> near the tail considered, if so and you opted not to
>>proceed
>> Could you explain why. Given the weight saving would
>>still be
>> about 6kg, it would seem worthwhile to pursue
>>
>> Craig========================
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