advise on wax wanted

I'm also interested in JJ's take on using any product that contains
silicone on gliders. *I've read some things that have made me very
paranoid about what touches my glider.

Its probably best to staw away from products that contain silicones,
but any repair involves a thorough sanding all around the repaired
area. I have never had any adhesion problems and that includes
glassing right up against fittings that were soaked in lubricants. I
grind until all the damage is removed and until I can no longer see
any lubricant in the structure, then scrub it down with acetone, dry
it well and start laying in the new material. Don't really see how
anything can survive the above to result in a problem.

On a completely unrelated subject, I'm getting back into R/
C.....................when I last flew we were driving a Babcock
escapement with a 3v transistor tone radio. WOW, have things changed,
but I have a couple of questions. How does a 'brush-less' electric
motor work and my radio says it is FM, but is crystal controlled, how
does that work?
Thanks and sorry for the unrelated questions, but I am flying an RC
Easy-Glider,
JJ

On Fri, 13 Feb 2009 02:35:19 -0800, JJ Sinclair wrote:

How does a 'brush-less' electric motor work

Its the inverse of a small DC motor: the coils are stationary and the
magnets are attached to the shaft. There's no commutator. Instead there's
an electronic controller that does the same switching job as a
commutator. Speed control is a bit different because changing the
throttle changes both the current the rate at which the controller
switches round the coils. Unlike a brushed motor, the RPM follows the
throttle setting rather than the load its driving: in aerobatics the RPM
stays more or less constant throughout a vertical maneuver.

You'll here talk of in-runners and out-runners. An in-runner has the
magnets inside the coils: they are smaller in diameter and more efficient
than out-runners, run faster and have less torque, so need gears to swing
a bigger, more efficient prop. An out-runner has the magnets outside the
coils: its larger diameter gives it more torque so it can drive a big
prop without needing gears.

Controllers look like a servo to the radio and accept the same type of
signal. The better ones do more than translate throttle position into
motor RPM - they have a soft-start capability to protect the power system
from a power surge if the throttle is suddenly slammed open and a safe
start facility to prevent the motor from suddenly starting if the radio
is switched on with the throttle open.

The Antares 20E uses an ungeared out-runner as its propeller hub: an
extremely simple, well-designed approach. This page has some good photos
and a cut-away diagram of their motor:

http://www.lange-flugzeugbau.de/htm/...s/antares_20e/
propulsion.html

and my radio says it is FM, but is crystal controlled, how does
that work?

I think that means the transmitter's center frequency is set by the
crystal. Swapping crystals moves the center frequency to another channel.

I'm not an RC flyer. I fly Free Flight competition models but am learning
about electric power systems in order to try the F1Q class.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Thanks Martin, that answers my questions. Last time I flew some 47
years ago with a rubber powered escapement and the "new" 3-volt
transistor radio that had just enough poop to trigger an
escapement.................loads of fun, one pulse gave you left
rudder, 2 pulses for right........but it worked and that was something
in 1962!
Cheers,
JJ

On Feb 13, 6:01*am, Martin Gregorie
wrote:
On Fri, 13 Feb 2009 02:35:19 -0800, JJ Sinclair wrote:
How does a 'brush-less' electric motor work

Its the inverse of a small DC motor: the coils are stationary and the
magnets are attached to the shaft. There's no commutator. Instead there's
an electronic controller that does the same switching job as a
commutator. Speed control is a bit different because changing the
throttle changes both the current the rate at which the controller
switches round the coils. Unlike a brushed motor, the RPM follows the
throttle setting rather than the load its driving: in aerobatics the RPM
stays more or less constant throughout a vertical maneuver.

You'll here talk of in-runners and out-runners. An in-runner has the
magnets inside the coils: they are smaller in diameter and more efficient
than out-runners, run faster and have less torque, so need gears to swing
a bigger, more efficient prop. An out-runner has the magnets outside the
coils: its larger diameter gives it more torque so it can drive a big
prop without needing gears.

Controllers look like a servo to the radio and accept the same type of
signal. The better ones do more than translate throttle position into
motor RPM - they have a soft-start capability to protect the power system
from a power surge if the throttle is suddenly slammed open and a safe
start facility to prevent the motor from suddenly starting if the radio
is switched on with the throttle open.

The Antares 20E uses an ungeared out-runner as its propeller hub: an
extremely simple, well-designed approach. This page has some good photos
and a cut-away diagram of their motor:

http://www.lange-flugzeugbau.de/htm/...s/antares_20e/
propulsion.html

and my radio says it is FM, but is crystal controlled, how does
that work?

I think that means the transmitter's center frequency is set by the
crystal. Swapping crystals moves the center frequency to another channel.

I'm not an RC flyer. I fly Free Flight competition models but am learning
about electric power systems in order to try the F1Q class.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

JJ -

Are you getting into R/C Slope-Soaring, Dynamic-Soaring, or
Thermalling?

Now that I fly the "real thing" I've left my R/C gear in the closet
for almost 2 years. I have several 4-ch to 7-ch radios and a half-
dozen models (a couple are built, a couple still need to be built, and
a couple need to be repaired). I've been meaning to donate or sell
'em for cheap to someone who'll use them... The models range from 42"
slope-soaring flying wings, to a big 3-meter thermal ship (
http://warpedspace.netfirms.com/graphite/ ). Email me if you have any
interest. I'll even be driving down from Seattle to Warner Springs in
late April for the R12 contest, so I could drop them off if you're
willing to drive out towards I-5 to meet me.

Am posting this publicly in case JJ says no, but I've piqued the
interest of some other soaring pilot who also happens to fly R/C...

Take care,

--Noel

On Fri, 13 Feb 2009 07:26:47 -0800, JJ Sinclair wrote:

Last time I flew some 47 years
ago with a rubber powered escapement and the "new" 3-volt transistor
radio that had just enough poop to trigger an
escapement.................

If you'd said 40 years, a Controlaire 5 receiver and Royal 'single
channel' servos that would be me too. I'd joined Wellington MAC about two
years earlier, so 40 years ago was when I dumped RC in favor of Free
Flight. We had a 5 day Nats, so I'd built a FF tow-line glider to have
something to do on the non-RC days and discovered thermals. I found them
much more fun than button pushing.

However, the old Royals were great: they worked just as you described:
'hold' for right, 'blip hold' for left and 'blip blip blip' to step the
three position throttle servo. The only difference from a traditional
escapement was that the servo had a small electric motor inside it in
place of the rubber.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Do any of the waxes described above (Mother's etc.) block UV? UV seems
to be the biggest killer of gelcoats, followed closely by damp (not so
much of a problem in Texas I imagine :-) ).


Dan

Wx/Block (weather block) and Racer's Edge both have high degree of UV
blockers
http://www.wingsandwheels.com/page44.htm
tim

"Dan G" wrote in message
...
Do any of the waxes described above (Mother's etc.) block UV? UV seems
to be the biggest killer of gelcoats, followed closely by damp (not so
much of a problem in Texas I imagine :-) ).


Dan