The Murphy Builders Site

$50 from the airplane parts store... $20 from the model airplane

;-)

http://www2.towerhobbies.com/cgi-bin/wt ... XPT31&P=ML

Mike

----- Original Message -----
From: "Bob Patterson" <beep@sympatico.ca>
To: <rebel-builders@dcsol.com>
Sent: Sunday, September 30, 2007 6:47 AM
Subject: Re: [rebel-builders] tach tests

Hi Garry !

Wouldn't it be a whole lot easier on everything to just buy an
optical tach - they're about $50. They read RPM directly from
light interrrupted by the propeller blades - 2, 3, or 4 ...
You could then read the RPM in flight - the Rebels natural setting,
OR - with a helper, get a reading just at the start of takeoff.

Any of you that uses the optical tach checkers and has any question
about accuracy, aim it at a fluorescent light. 60 cycles as generated
in the US and the reading should be 3600.
Although not a US requirement I check the tach accuracy on every annual
inspection that I do.

Dick Wampach SR-108


Subject: Re: [rebel-builders] tach tests

Should probably mention too that I've used one of these in my 150 in
flight
and had no problem reading through the windshield... just pointed it
into
the sun to give the most contrast between blade and no blade.

Mike

----- Original Message -----
From: "Mike Davis" <mike.davis@dcsol.com>
To: <rebel-builders@dcsol.com>
Sent: Sunday, September 30, 2007 12:42 PM
Subject: Re: [rebel-builders] tach tests

$50 from the airplane parts store... $20 from the model airplane

store.

;-)

http://www2.towerhobbies.com/cgi-bin/wt ... XPT31&P=ML

Mike

----- Original Message -----
From: "Bob Patterson" <beep@sympatico.ca>
To: <rebel-builders@dcsol.com>
Sent: Sunday, September 30, 2007 6:47 AM
Subject: Re: [rebel-builders] tach tests

Hi Garry !

Wouldn't it be a whole lot easier on everything to just buy an
optical tach - they're about $50. They read RPM directly from
light interrrupted by the propeller blades - 2, 3, or 4 ...
You could then read the RPM in flight - the Rebels natural setting,
OR - with a helper, get a reading just at the start of takeoff.

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$50 from the airplane parts store... $20 from the model airplane

;-)

http://www2.towerhobbies.com/cgi-bin/wt ... XPT31&P=ML

Mike

----- Original Message -----
From: "Bob Patterson" <beep@sympatico.ca>
To: <rebel-builders@dcsol.com>
Sent: Sunday, September 30, 2007 6:47 AM
Subject: Re: [rebel-builders] tach tests

Hi Garry !

Wouldn't it be a whole lot easier on everything to just buy an
optical tach - they're about $50. They read RPM directly from
light interrrupted by the propeller blades - 2, 3, or 4 ...
You could then read the RPM in flight - the Rebels natural setting,
OR - with a helper, get a reading just at the start of takeoff.

Date: Sun, 30 Sep 2007 19:31:00 -0800
From: mkimball@gci.net
Subject: RE: [rebel-builders] tach tests-CALIBRATION
To: rebel-builders@dcsol.com

And don't forget the poor man's tach check. Put a little piece of duct tape
on the back of one prop, back your plane up to a floodlight somewhere on the
airport and run your plane at night. If your country is using 60Hz AC the
prop will appear to stop at all multiples of 60. I check at 1200, and 1800
with just the brakes holding me. If you can tie the plane down, check at
2400. For 50Hz countries, do the simple math. It worked great for a Piper
Arrow I used to own whose tach was placarded as reading 100 RPM low. I
wanted to know, so I checked it this way and sure enough, the prop appeared
to stop 100 RPM lower than it should.

Mike
044SR

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of
Richard Wampach
Sent: Sunday, September 30, 2007 2:34 PM
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] tach tests-CALIBRATION

Any of you that uses the optical tach checkers and has any question
about accuracy, aim it at a fluorescent light. 60 cycles as generated
in the US and the reading should be 3600.
Although not a US requirement I check the tach accuracy on every annual
inspection that I do.

Dick Wampach SR-108


Subject: Re: [rebel-builders] tach tests

Should probably mention too that I've used one of these in my 150 in
flight
and had no problem reading through the windshield... just pointed it
into
the sun to give the most contrast between blade and no blade.

Mike

----- Original Message -----
From: "Mike Davis" <mike.davis@dcsol.com>
To: <rebel-builders@dcsol.com>
Sent: Sunday, September 30, 2007 12:42 PM
Subject: Re: [rebel-builders] tach tests

$50 from the airplane parts store... $20 from the model airplane

store.

;-)

http://www2.towerhobbies.com/cgi-bin/wt ... XPT31&P=ML

Mike

----- Original Message -----
From: "Bob Patterson" <beep@sympatico.ca>
To: <rebel-builders@dcsol.com>
Sent: Sunday, September 30, 2007 6:47 AM
Subject: Re: [rebel-builders] tach tests

Hi Garry !

Wouldn't it be a whole lot easier on everything to just buy an
optical tach - they're about $50. They read RPM directly from
light interrrupted by the propeller blades - 2, 3, or 4 ...
You could then read the RPM in flight - the Rebels natural setting,
OR - with a helper, get a reading just at the start of takeoff.

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