Model Forum / Radio Controlled / Helicopters / March 2008

but even if you do restore it its going to be converted back to a pile
of bits very quickly and if it hits you in the process its going to
bloody hurt or even kill
there are so many more easier Helicopters to fly on the market and just
because its old is no reason to restore it ,but if you do continue best
of luck as boy are you going to need it
its a bit like restoring an 1885 Carl Benz 1st car and taking down the
M4 to Wales yes you could do it,but would it be practical no, would it
be safe no , would it be a laugh no ,

He is basically right. If you want a helicopter to fly with, you don't
get a Sport 500. Similarly, if you want a car to drive with, you don't
get a T-Ford. But if you like tinkering with old technology and like
making your own spare parts from a block of metal, an old-timer
helicopter can probably be just as much fun as a old-timer car.

The Sport 500 was designed in a time where a helicopter radio was
beyond most modeler's budget, and most modelers would already own a
.40 size plane engine. The intention, therefore, was to design a heli
that can be powered by a normal plane engine and flown with a
standard, four channel radio.

Yes, I agree it's a matter of perspective. But make sure your
perspective is what you think it is. If you want to get this machine
flying in order to have a cheap, fun flying time, you are wasting your
time. If you want to try to make the thing work simply because of the
fun of the challenge itself, I applaud your courage.

It was also called a "teeter damper wire", if I remember correctly. It
was simply a short piece of extremely hardened wire that would connect
the rotor read with the mast. They were bought in packs of five or
ten, as they kept breaking all the time. A slightly heavy landing was
all it took to snap the wire.

I have seen a video where someone actually flew the thing, but I have
never seen it fly myself, apart from some short, wobbly hovering hops.

If you have no experience flying helis at all, you will not be able to
get the Sport 500 into the air. Ask an accomplished pilot for
assistance. Whether you want him to actually try to fly it, or if you
tell him to just "let it rip", is entirely up to you. Either way,
please video the event and post it on Youtube or some other public
place where everyone can enjoy it.

I have to admit: If I could find a Sport 500 for free, I, too would
take the challenge and try to get it flying.

I'm surprised by the hostile responses to your request; yes it's an old
design, yes modern helis are easier to fly, but it's still an interesting
retro model well worth restoring. Despite the doom mongers on here, the MFA
fixed pitch does fly pretty well, just requires more care than modern models
in assembly and setting up. I had an even earlier version of this model that
came with a plastic head and Hughes 500 body, which did fly despite being
under powered by a Webra 40 Blackhead. With a powerful modern 40 size engine
and a HH gyro, this later version should be a doddle, relatively speaking.

Spares are scarce, not even sure if MFA are still around, so this may be
your major stumbling block. The teeter spring you mention is simply a piece
of piano wire (music wire to our American cousins) that was fixed to one
side of the head and is esily sourced.

As for test flying, I would have no qualms whatsoever about being there,
would even volunteer to fly it myself.

Paul.

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 Sport 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 passes 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 bitch, 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

 There used to be one of these things in the bottom of a wardrobe at my
gran's house, about 16yrs ago when I used to stay there at weekends. I
use to twiddle its linkrods (ooh err) and fantasise about it flying (! :D )

It's probably still there now. I remember my uncle telling me how his
buddy bought/acquired it and tried to fly it once... straight into a
tree or the ground or something.

It's wooden I think. And painted a combination of red and oil.

It's taken you 12 years to concnve yourself yoou're a mad as a f.cking 
hatter?

It'll be the first time not a "return to". The MFA was, is and always will
be a total pile of shite. Even my bin would spit the f.cker out.

And he'd be dead right too.

That's a bit like digging up an old whore and shoving 500,000 volts up her
jacksie because "she f.cks". there are FAR better ways to spend your time
y'know. Squeezing blackheads would come before rebuilding a 500 too. More
rewarding and definitely more likely to succeed.

No it's not. The MFA was a lost cause before it was even a casue.

You're doomed to disappointment if you think you're going to fly this thng.
Waste your time, by all means, but that's exactly what you WILL be doing.

The teeter spring is a short length of piano wire that attaches under the
rotor head and contacts with the "see-saw" that IS the rotor head. It's job
is to "control" the speed at which the rotor deflection is carried into the
rotor mast. It was crap in the 70's and it'll be crap in the Noughties too.

But that's the BEST advice you could get.

It won't be its final flight, it'll be it's first and only. Why not just rip
a few quid up and slot them down the nearest grid and take your time doing
it, coz you'll only be wasting time and money f.cking about with that POS.

Of course, I AM being very restrained.