Model Forum / Radio Controlled / Air Models / May 2004

Why not?  You'll make friends, and flying with somebody definitely beats
flying alone.  Also, with an instructor, your chances of crashing are
greatly decreased.

Gas - cheaper, higher power/weight ratio.
Electric - quieter, more convenient.
There have been numerous conversions.  Usually a gas to electric conversion
involves replacing unneeded plywood with balsa and lightening  the airframe.
Gas engines produce a lot of vibration that requires beefing up the
structure.

Not necessarily true.  I've seen some very fast electrics.  Like gas, it all
depends on the type of airframe, the motor and prop you use, and what kind
of batteries you have.   However, do you really want a fast plane?  Fast
planes need quick control responses, something you don't have when you have
to think about what stick which way gets the plane to do what you want.

Electrics are very quiet compared to the mosquito-on-steroids sound of an
unmuffled .049.
Usually there is a little noise coming from the motor and prop, but it's
much less than glow.

That depends on the motor and battery system you're using, and how you use
your power.
Typically, you can get 5-8 minutes with NiCd batteries, a bit longer with
NiMH, and about 15-20 minutes with the new LiPolys.  As they say, your
mileage may vary.

I suggest you read up on electrics at www.ezonemag.com and since you want to
design your own, a program such as MotoCalc (www.motocalc.com) would be
indispensable.  MotoCalc can calculate the performance for various
combinations of airframes, motors and batteries.

Hope this helps,
Morris

I can relate - I approached flying the same way...  By the way, I did crash
and burn, several times!

It's certainly possible to convert gas to glow, or glow to gas, although
that's something that's best done _before_ the plane is built.  Electric
doesn't demand such a strong airframe, but will benefit from a lighter one
(because of the battery weight you mentioned).

Sorry - I've not flown any glow powered planes to make a comparison (I've
seen a very few flying).  My electric Piper  is pretty quick though, and a
little heavy (it's my "high wind" plane).  It may do around 20mph?

Comparatively, yes.  Direct drive planes are very quiet - with geared motors
you can get a little gearbox noise.  The noise goes up with size - I have a
48" GeeBee Z that may be as loud as a glow plane.

I have two small foamies - I fly the Piper on NiMH for 20 minutes on a
battery (and the batteries are cheap enough to buy two), and a Bearcat I fly
on Lithium-Polymers.  Some days I can't fly long enough to hit the end of
that one...

On 5/14/2004 7:08 AM Ted shuffled out of his cave and grunted these
great (and sometimes not so great) words of knowledge:

First, The E-Zone  http://www.ezonemag.com/  has a lot of VERY GOOD
information.

Electric is quieter than glo.  Because the noise level is substantially
lower, they can be flown in areas that would normally not allow flying.
 The plane is clean after flying and less peripheral equipment for the
field is needed.  Unless you use brushless motors, power is usually
limited.  Electrics can be substantially more expensive than glo.

Is it even possible to take a plane designed for gas

It is possible and there are MANY glow to electric conversions.  It is
easier to do with a kit than an ARF, since you will need to lighten the
airframe by removing pieces that aren't needed and/or substituting
lighter wood in areas that do not need it due to the lack of vibration
from electric motors compared to glo.  The big thing to watch out for is
the wing loading - how many oz of weight per square inch.  The lighter
the better, especially for electrics.

MOST electric trainers and park flyers have difficulty in winds over 5
mph.  Electric trainers USUALLY have a top speed of about 15 mph and
cruise at a slightly faster than walking speed.

MOST 40 size glow trainers have little if any difficulty in 10 mph
winds, however, they USUALLY take off and land at ABOUT 25 mph, cruise
at ABOUT 40 mph.

The simple answer to your question is:  If you have 20 knot AVERAGE
winds, learn on a 40 or 60 size glo plane.  They will USUALLY have a 50
- 70 inch wingspan and weigh 5 - 7 lbs ready to fly.  Because of the
heavier weight they can handle the wind much better and their larger
size makes them easier to see and see what they are doing.

The down side to them is:  You need a substantially larger area to fly
them in.  A football field is way to small.  They are louder than
electric and you will have to spend about 5 minutes at the end of the
day to clean them (no biggie - some paper towels and Windex).  You will
need more peripheral equipment at the field to fly them.  You will most
likely have to travel further to get to a flying field.

Electrics are USUALLY substantially quieter than glo.  A good percentage
(maybe 25%) of the noise is from the prop.  More efficient props are a
lot quieter.  I have reduced the noise level about 8db on my 40 size
planes just by switching to a more efficient prop.

THE MAJORITY of low end trainers/park flyers using BRUSHED MOTORS and a
NiCAD/NiMH battery have a flight duration of about 5 - 7 minutes.  With
PROPER THROTTLE MANAGEMENT, that can be extended.  Using brushless
motors ($$$) and a LiPo battery ($$$$$$$), 30 minute flights are common.

Whether you want to learn how to fly using electric or glo I HIGHLY
RECOMMEND the following:  Find a club, and get an instructor.

It is possible to teach yourself how to fly, there are people who have
done it.  Teaching yourself to fly though, is a VERY STEEP learning
curve and quite frustrating (not to mention expensive).  The USUAL first
flight for someone teaching themselves to fly is UNDER 30 SECONDS and
USUALLY results in "rekitting" of the plane.

Remember, you have a prop turning at several thousand rpm, not to
mention the force of the plane itself if it hits someone.

Hope this helps.

The biggesst tradeoff I see is money!!!!! I bought a 3 phase electric
motor with gears and a speed controller, whiz bang battery charger $$$,
special prop and adapter/spinner,battery pack, .... it may not stop
here....many $$$$ involved and that doesnt include the airplane nor
radio. Probably 500 $$$ so far. I could have bought a real nice glow
engine for that. 4 stroke.

Unless you spend a little more on the electric, teh gas will outperform
it. However this is not an issue with sport models.

Use of LIPO cells (very feasible at this size, and not expensive) will
net you a plane that is very similar in weight and power to a glo.

24" is small tho - its either going to be fast, or VERY light. I am
flying 26" span electrics on 15W power units.

Not really. Its just a tendencty to build over weight overpowered glo
planes. If you want a model that will handle wind, 26" span is not it...

You need about 50" span, and 3-4lb weight. Very doable on .25 glo or
speed 600 sort of electric power.

Theres prop noise and tehre may be gearbox noise and some motor noise as
well. Quietest are direct drive outrunners - multi-pole morirs that rev
slower.

For electrics, its generally 3-5 minutes for Nicads, 5-8 minutes for
NiMh cells, and 10-40 minutes for lithium polymer.

Moving away from what you are directly asking, to what I think you
really want to know....

...If you want a trouble free modelling experience flying off small
local fields with slower lighter models, then something in s the speed
400 class electric preferably equipped with lithoum polymer batteries
for decent duration, is absouletely spot on. 36-45" span and 17-23 oz is
the norm. The advantages are local field flying, no slime, quiet, and
not horrendously expensive. The disadvantage is a flying speed more like
25mph than 40mph, and it does nothing to teh size of your penis.

...if you have a good club field and friendly flyers close by, a
standard .25 to .40 model weighting 3-5lb and in the 50-70" span range
will over you huge penis size increases, a flying speed in teh 30-40mph
range and fast turn round times between typically 6-15 minute flights.

You WILL need a take off and landing strip - these models are nearly
always too fast to reliably hand launch - and somewhere where noise is
not an issue. Price is SURPRISINGLY comparable by the time you have
added up all the anicillary bits you need to go in the flight box of either.

Esdentially its a style choice, and not as irrevocable a one as people
like to say. If you have (as I do) suitable flying sites for smaller
electric models within walking distance, its a bit of a no brainer. I
just wait for calmer days.

OTOH if you have to make the trip to a club field anyway, there is very
little to choose. Bigger electric models of comparable performance to a
40 glo ARE more expensive.

I prefer electric, and have ended up spending more money for the
convenience of flying where a glo plane is simply not feasible.

If you DO go electric, the one thing worth spending money on is decent
lithium polymer bateries and a suitable charger. Those batteries at one
stroke lift the models perform,ance from 'adequate' to 'very enjoyable'
...power to weight approaches and may even exceed glo power at sensible
(>6 minutes, usually 15) duration levels. With more power avialable at
lighhter weight, there is not so much presure on the motor and a larger
cehaper one is often as good as spending hundreds of dollars on the
latest brushless screamer, but staying with cheaper batteries..