Re: 049 test stand dont's

Don Stauffer in Minnesota wrote:
> On Jun 27, 10:00 pm, Tim Wescott <t...@[EMAIL PROTECTED]
> wrote:
>> Got a Cox reed valve 049 engine going today, with a Davis head.
>>
>> For a motor stand I'm using a Tatone stand with a piece of 1/8" angle
>> iron on which the engine is bolted.
>>
>> Don't do this, unless you want some practical education in resonances.
>> At the 'bad frequency' (which was just a bit lower than what the engine
>> really wanted to do) I could see the cylinder moving through a 1/4"
long
>> arc.
>>
>> Very disconcerting.
>>
>> But I could damp it out by hanging on to the engine, so I verified that
>> it runs (and smells) normally for a little Diesel conversion, and I
have
>> the compression and mixture at a good setting to go on a plane.
>>
>> Tomorrow I go flying.
>>
>> Sometime soon I go get some nice thick T-bar and make a new test stand
>> adapter for 049s!
>>
>> --
>>
>> Tim Wescott
>> Wescott Design Serviceshttp://www.wescottdesign.com
>>
>> Do you need to implement control loops in software?
>> "Applied Control Theory for Embedded Systems" gives you just what it
says.
>> See details athttp://www.wescottdesign.com/actfes/actfes.html
> 
> Okay, taking this thread a bit off-topic, can one still buy a half A
> engine? I have a project in mind, but understand you cannot buy half A
> engines anymore.  The only one I have left is a Cub, and that is
> dedicated to a vintage Ukie kit- do not want to use it on a new RC
> project.

As pointed out, Brodak sells 'em.

OK engines makes a reed valve engine -- search for "OK Engines" on the
web.

As of a year or two ago Norvel made a s****t and a high performance 
version, both ABC, each available as both RC and CL (I actually 
considered buying a Norvel 061 for this plane, but no one had it locally).

Dr. Diesel has British 1/2A diesel engines.

Rummage sales and/or inquiries at your local flying club may find enough 
Cox engines that your bucket-o-engines will be bigger than mine.  Just 
let all your flying buddies know you'll take old Cox engines off their 
hands, and you'll be getting them long after you say "stop".  You can 
get all the rebuild parts for Cox engines from various sources -- I use 
the nice teflon pieces available from Davis Diesel, plus an 'O' ring for 
the venturi-to-backplate seal made by cutting off a ring from a bit of 
silicon tubing with a Very Sharp xacto knife.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html