Re: 049 test stand dont's

Flash wrote:
> "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 
> 
> 


The theory is that if you can stay focused on a point longer then 
acquire another focus point your senses aren't as confused.  Spatial 
disorientation from spinning is different that vertigo.

Jim