On Wed, 12 Mar 2008 12:55:08 GMT, "Leeds-Mick via ModelGeeks.com"
<u42018@[EMAIL PROTECTED]
> wrote:
>I've spent the last 12 years trying to persuade a freind of mine to sell
me
>this old model helicopter hes had, sitting in bits in his garage for 12
years
>or more. He wouldnt, and still hasnt, but, about 2 months ago, he gave me
it,
>and asked me to see if i could return it to flying condition.It has no
>identifying marks on it, and he had no idea what it was, so after a lot
of
>cleaning and sorting, i took the main frame to my local Model shop. The
>gentleman there, first laughed, then commented on how he hadnt seen one
of
>these in years, and identified it as the s****t 500. He told me that they
were
>crap 20 years ago, id have no chance of finding parts, including blades,
and
>the best thing i could do was throw it in the bin. My freind and I have,
>however, decided to make it our 'Bolton Paul Defiant' project, where you
take
>a useless old aircraft, and restore it to flight, simply because its old.
All
>my research, which has led me here to you guys, tells me the man in the
shop
>was right, but i hold to the belief that its all a matter of perspective.
To
>him with his 3d turbo ninja t rex'd honey bee's, and his years of flying
>experiance, our aircraft is a complete and utter waste of time, and no
doubt
>many of you will share his belief, but ive never flown any models ever,
only
>the real things a few times, many years ago, so its still an exiting
project
>for me. I ve discovered from my resaerch, that there is something called
a
>teeter spring, which ours doesnt appear to have, so i am hoping that
someone
>out there will be able to provide me with a manual, and a little help and
>advice, other than bin it. Even if its final flight is an acceleration
into
>mother earth, it ll still have been a interesting engineering experiment,
and
>a damn good laugh!
There's no reason you shouldn't be able to fly this machine, and have
allot of good safe fun with it.
I had a MFA S****t 500 in 89 and found it to be quit rugged and got a
lot of enjoyment from it, it was my third heli and the first one that
had a legitimate retirement, the first two dam near had to be buried.
I also overhauled one three years ago for someone that picked his up
at a yard sale, it hovered fine when I tested it, and the owner
hovered successfully, I didn't fly his machine in full foreword flight
I couldn't justify taking the chance with his machine until he was
ready for full foreword flight himself, I tolled him that I would fly
it then, but it never came to that point he didn't stick with it.
But I did fly mine, not very good or fast, with the heli about 50 feet
away I turned in a circle as if I was flying a control line, it was
the only way I could do it at the time.
Here's a couple of bits of info you might find useful, you definitely
want to replace that teeter wire, it's function is to dampen the head
if you ever break it on a hard landing and didn't notice it you'd find
out in a hurry how affective it is, the machine will be quit violent,
quick and easy to over control.
Get a piece of spring steel at your local hobby shop (if I remember
correctly it's 3 mm) and start cutting, they break easy.
During your rebuilt make sure you check the ball links good, visually
and manually,give them a little tug, I've seen the plastic part that
goes over the ball split but still stay on till a little pressure is
applied.
The wooden structure that the canopy fits over should have it's
glue joints inspected, give everything a little twist and pull, you'll
want it to fail on the work bench preferably and not in the air.
When you get it going make sure that you give the main gear and
the tail drive wire where it p***** through the hangers that are
attached to the tail boom a little oil each day, lf these spots run
dry the metal on metal can generate noise that can interfere
with your radio.
Have fun starting it because it's a *****, you'll be chasing that
little starter belt allover the flying field, I replaced the starter
pulley with a custom starter cone I machined, if this is an
option you might want to think about it.
If your going to give it a try build borrow or purchase training
gear(I.E. two hardwood dowels in an X and Wiffle Balls on the
ends of the dowels).
The big drawback of a fixed pitch machine is how slow they
react to throttle input, if you're using a simulator to practice on
you're probably training with a machine that has collective pitch,
in theory collective pitch machines maintain a constant head speed
so when it's descending head speed does not diminish, and when
collective is applied the response is almost instantaneous.
A fixed pitch machine can only descend by lowering the head speed
and this is where a big problem can occur, you need to anticipate
your flare fare sooner with a fixed pitch verses collective pitch.
For example if you where flying a fixed pitch machine in a 5mph
wind the head speed would be quit low by the time it was
descending so you would need to apply power at 15 to 17 feet
to stop it at 3 feet because the head speed needs to build up.
This also applies to hovering the power will need to be applied
sooner than you think compared to a collective pitch machine
when landing if you want to land soft.
Hope some of this helps.
Have fun with your project.
Don
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