John,
I am interested please in the dual finger brakes and was wondering if you have
a PDF file on its installation, and a costing and availability please? In
anticipation.
Reg
Tony Renshaw
>
>Hi All,
>
>Lockwood recomends a hobbs to record engine time for oil changes, other
>regular maintenance & diags. Both Mitchell, and UMA make electronic
>tachometers with a time readout. Mitchell also makes a 2 1/4" mechanical
>recording tach for the Rotax 912 / 914.
>
>Hope this helps.
>
>John Hurst
>Europa Aircraft
>Lakeland, FL
>
>-----Original Message-----
>From: Jim Brown <acrojim@cfl.rr.com>
>To: europa-list@matronics.com
>Subject: Re: Europa-List: Hobbs switch
>
>
>On N398JB we connected the Hobbs meter to the Master switch, which
>eliminated any taping into the oil system for pressure. If we need to have
>the master on for what ever reason without the engine running we simply
>pull the circuit breaker.
>
>Jim Brown
>
>n3eu@comcast.net wrote:
>
>>
>> > This has probably been discussed a million times before. Typically when I
>> > am involved in a certain section of the build I become focused and tend
not
>> > to assimilate some of the other stuff coming over the web. I need to
>> > install a switch for the Hobbs meter. The first thought is to put a T
>> > where the oil pressure transducer is and plug in the switch upstream of
the
>> > transducer. Are there any other pressure ports on the 914 that I'm not
>> > aware of? What have others done to ensure accurate recording of engine
>> > hours with the Hobbs?
>> >
>> > Thanks,
>> >
>> > Steve A143
>> > Mesa, AZ
>>
>> Why do you really need to know accurate Hobbs time? As an amateur-built
>aircraft in the U.S., you're not bound in the slightest degree by any run
>time of any component anywhere. Admittedly, were you to sell the aircraft,
>airframe/engine time will be of interest to a buyer and thus how determined,
>but big deal.
>>
>> So, my "Hobbs" time is from that which a Taskem digital RPM display
>actually records in nonvolatile memory. Good 'enuf!
>>
>> The only place to tap into oil pressure is at the pressure transducer on
>all Rotax 91X, or the feed line to the 914 turbocharger. But the grizzled
>old aircraft mechanic in me says you do that you introduce a point of
>failure in a critical airworthiness system. It's not like there's a Service
>Bulletin on my other airplane specifically on this, which on failure causes
>oil to be spilled inside the aircraft cabin, until there ain't nuthin' in
>the sump!
>>
>> Thus preferable would be to simply read voltage at the Rotax transducer,
>and glomp a transistor to fire a stock Hobbs meter. It's a simple circuit,
>but if a builder can't do that, I think it best to at least shop for
>something that will record elapsed hours when fed a voltage, like when
>master is on -- even a stock Hobbs does that. It won't be exact engine
>hours, but so what.
>>
>> Regards,
>> Fred F.
>>
>
>
|