Re: 049 test stand dont's

"Jim Chandler" <n427c@[EMAIL PROTECTED]
> wrote in message 
news:8Bz9k.51$Ae3.12@[EMAIL PROTECTED]
> Tim Wescott wrote:
>> Jim Chandler wrote:
>>
>>> Tim Wescott wrote:
>>>
>>>> MJKolodziej wrote:
>>>>
>>>>> "Tim Wescott" <tim@[EMAIL PROTECTED]
> wrote in message 
>>>>> news:B6-dnQFFFODdNPjVnZ2dnUVZ_uudnZ2d@[EMAIL PROTECTED]
>>>>>
>>>>>> 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 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
>>>>>
>>>>>
>>>>>
>>>>> Cool!
>>>>> How did you start it? Power or fingers?  Fuel tank attached or
apart?
>>>>>
>>>> It's got a Babe-Bee tank.  Unfortunately it's going onto a plane
that's 
>>>> got a Golden Bee right now, and will need a spacer to get the prop
out 
>>>> far enough to clear the cowl.  So, maybe I fly Sunday.
>>>>
>>>> Cox 049s without mods don't do well being started with an electric 
>>>> starter.  It can be done, but the prop drive and crank case are both 
>>>> aluminum, so they get chewed up pretty quick.  There were supposed to

>>>> be some marine engines that had bronze or brass prop drives which are

>>>> supposed to work better.
>>>>
>>>> I've been thinking of taking one of my chewed-up crank cases (guess
how 
>>>> they got that way!) and fitting a steel collar at the end of the
crank 
>>>> case to run against the prop drive; dunno if I'd go to the trouble of

>>>> turning out a brass prop drive.
>>>>
>>>> At any rate, this one starts with a generous prime and a few healthy 
>>>> flips by hand.  I had been using a chicken stick, but did you know
that 
>>>> rubber turns to black gunk in the presence of diesel oil and ether? 
>>>> Fingers don't...
>>>>
>>>> The big challenge was getting the needle and compression adjustments 
>>>> sorted out the first time; now it should go without adjustment.  I
need 
>>>> a tach, but it's turning a 7-4 prop 'good and fast' -- it sounds
barely 
>>>> slower than a glo 049 with a 6-4 prop, so it should pull my slightly 
>>>> oversized control line job around pretty well.
>>>>
>>>
>>>
>>> Good Gawd!  You mean someone actually still flies .049 Ukies?  I have 
>>> done that since I was a kid.  It WAS fun though.
>>>
>>
>> It still is.  Cheap, too, as long as the bucket-o-engines holds out.
>>
>> I haven't done it for a while, so I expect to get dizzy -- this is the 
>> driver behind the small tank, and may also lead to some BB's or bits of

>> Teflon in said tank until my middle ears adjust.
>>
>
>
> Or you could use the ballet dancer/ice skaters trick and keep your head
in 
> one spot for a quarter turn or so then snap it around to catch up with 
> where everything is then do it all over again.  Gives the ears a chance
to 
> stay equalized because the fast head movement then stop is faster than
the 
> ears can be upset.
>
> Jim

Jim, I don't know what kind of vertigo those dancers and skaters have, but

that did not work with my variety, for sure!

I quit U-control in the 80's because.      (Hmmm... I wonder? Time has 
passed, and the hobby shop is only 5 minutes away and an .049 would be a 
cheap experiment)

Flash