Switch to Electric?

Unbelievable. I wonder how much the electric model weighs and compares in weight to the YS powered versions?

Ed Cregger

Reply to
Ed Cregger
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Given unlimited budgets, just about anything CAN be done. I would dare say that MOST modelers wouldn't tolerate the cost of getting performance equal to the larger glow offerings.

Reply to
Paul McIntosh

Reply to
arnereil

It must be incredibly heavy! 3 HP is about 2250 watts! And, to do that for

15 minutes is amazing. Most guys talk about 20 cells for 750 watts and 10 minute flights.

Reply to
Paul McIntosh

Q500s are in the 180mph range and the old F1s were well past 230.

Reply to
Paul McIntosh

I still think you need to get out more. The world of electrics is miles beyond what you apparently think it is. The prices are not nearly as high, nor is the performance nearly as low as you contend. As for matching glow performance, there are indeed off-the-shelf airplanes and systems that will do so handily.

Moe

Reply to
Moe Blues

He is also modifying it. That usually means making it lighter because otherwise performance is poor.

I don't see anyone saying it can't be done, just that you better be prepared to pay the price if you expect the same performance!

Reply to
Paul McIntosh

I haven't heard.

Drat. I should have copied the URL for the model's test flights. It might have more details.

The model has to come in under 11 pounds for FAI competition, of course.

Marty

Reply to
Martin X. Moleski, SJ

I think someone suggested that six or seven sets of batteries were in the $4000 to $5000 range (retail). Jason is probably getting some sponsorship.

Marty

Reply to
Martin X. Moleski, SJ

You are right, Marty. I forgot about the eleven pound limit.

Ed Cregger

Reply to
Ed Cregger

Some notes gleaned from the beginning of the video:

Hacker C50 13xl

Geared 6.7-1

20x13 APC prop

10S4P-2100 Thunder Power LiPoly Cells

65 Amps

11 lbs

200 watts/pound

My apologies if I have transcribed anything wrong.

Marty

Reply to
Martin X. Moleski, SJ

Agreed. Even trying to get much more than a few minutes of flight is still beyond the average modeler's reach. The amount of power per unit weight is still grossly in favor of the slimer.

Reply to
Paul McIntosh

But not for long. Truly cheap brushless motors will be debuting in this country before the end of this year.

Moe

Reply to
Moe Blues

| Power density indeed favors IC at this time. But give it another year | or so.

I think it'll take far more than a year before batteries can give a higher power density than wet fuel.

However, the fuel cells that they've recently approved for use on airplanes certainly shows potential -- have an electric plane that runs on alcohol, that could give you the best of both worlds!

| > > Your challenge is to design an electric within the same constraints | > > (mainly, it needs to be 11 lbs or less) that can fly across the | > > Atlantic. He has a (sort of) unlimited budget, so so can you :) | | Just hand me the brushless motor, some solar cells, and some Li-Po | batteries. It should be no problem.

I was hoping for a little more than a `proof by handwaving.' :)

I suspect it's going to be a bit harder than you've suggested. NASA's Helios looked very promising, and certainly had a (by our standards) unlimited budget, but it broke up once they tried adding batteries to the mix. But it's a bit larger than 11 lbs ...

(And using solar cells is cheating a bit, especailly when you're trying to show the high power density of your Li-Poly batteries, but they'd certainly be valid for a transatlantic crossing attempt.)

Making a < 11 lb solar powered glider is certainly doable, and it has been done, and it doesn't require a massive budget. But making one that that can cross the Atlantic (which will require carrying and charging batteries in flight) is another matter entirely.

| On the other hand, something like this has already been done by an | electric remote-control airplane

Somebody flew an 11 lb electric R/C plane across the Atlantic? I don't suppose you can provide some details? (I'm rather skeptical.)

| NASA has flown a couple of UAVs (all electric) for more than 24 | hours.

Can you provide a reference? I don't even think Helios ever kept flying for that long. It was part of the ultimate plan, but I don't think they did it (on 08/13/2001 they did have a 17 hour flight.) The Heron UAV has made a 52 hour flight, but it's not electric, and it's

2000 lbs rather than 11 lbs.

Maynard's challenge is to do it within 11 lbs -- after all, somewhat larger unmanned planes have already flown across the Atlantic.

I think you're going to have a very hard time designing an electric plane that can fly for 24 hours without the benefit of either 1) slope or thermal lift or 2) solar or some other form of power.

| > > (Still, you can get a pretty good plane for not much more than the | > > equivilent glow plane. But once you get past the electric `sweet | > > spot' of a speed 400 motor, the price starts shooting up.) | | But not for long. Truly cheap brushless motors will be debuting in this | country before the end of this year.

I'm skeptical, but that would be *so* sweet ...

Reply to
Doug McLaren

Also, the power density of solar cells make them pretty much useless except for keeping a small receiver battery charged.

There are slimers that have met the 11lb restriction and have stayed aloft more than 24 hours. And, no one has even tried to optimise a diesel for this yet.

Reply to
Paul McIntosh

Marty and others here are some prices. Look below.

$399

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$212.50 Speed controller Hacker HM 77-3P Opto
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$20 each?

2 packs of 5S4P ($325 each) $700
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> 65 Amps No charge....

That's $1311.50 for the power system without the charger. The charger will cost another $329 Orbit Micro Loader Pro

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now his fuel is nearly free.

What does a Y.S. 1.40 DZ with pipe and anti vibe mount cost? How much dose a serious pattern pilot spend on fuel? Can you see where this is leading? Now add to that the wear and tear vibration causes on the airframe and electronics and it isn't hard to understand why electric power is an attractive alternative. Plus, you can kiss good bye mixture settings, glow plugs, flameouts, noise, mess.....What's not to like?

I have no idea what Jason's airframe costs but I doubt it's significantly different that a Y.S. 1.40L powered version of the same airframe. Radio components should be exactly the same.

One thing people didn't mention is that the "light weight" and "high energy storage" of the LiPoly batteries is what this is possible for Jason. Just a year ago or so most electric planes were heavy and flight duration did suffer badly compared to glow power. Technology is a wonderful thing.....embrace it guys. Someday we may all have to fly electric planes in order to keep our flying fields.

Wiz

Reply to
Mike Wiz

The Ballistick will climb OOS in about 6-10 seconds. It is a SERIOUSLY powerful setup.

Reply to
Paul McIntosh

None, if you are prepared to fly larger and more exopensive E-planes.

You need about 75W/lb AUW - on normal cells this menas that you will add

30-50% of bare airframe in terms of cells and motor.

On the new Lithium cells, it may be less.

That is really dreifting towards Lithoiums. Its expenive at teh sort ofd sizes you are taliking about, but worth it.

An expensive one :-)

In the bigger sizes, a LOT. maybe upwards of $500 for motor, controller, cells and charger.

You need to immediately join the E-zone

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and get asking over there.

El;ectrics are cheaper than golo in te smaller sizes, but teh price sacles linearly with te size unlike glo, where a big engine and tank is not much more than a smaller one.

If you can find a plane that will fly on .25 - .36 sort of power, then it won't be as expensive to get what you want. .40-.90 sized planes require a LOT of pricey batteries to get super performance. Can be done tho. 20 minute flights with full vertical and a couple of horsepower on tap....but boy its expensive.

OTOH I can field a tiddly little parkflyer for about $200 including everything except transmitter and charger.

Reply to
The Natural Philosopher

I'd question the former actually with Lithium technology. The latter is still sadly very much the case.

However show me the glo engine that you can totally stop in flight and restart...or a glo plane I can fly for 20 mins and land in 10m of back garden...

Reply to
The Natural Philosopher

Hi Ed. Thats why I started, for sure.

But then I hit teh e-zone, and realised there was so much more possible.

What you find with electrics is that actually, unless you want utter ballistic performance, motors are very cheap ($5?) Its the controller and battery that cost more, but hey, lets say you want to build a 4 engined Lancaster or B17, that won't quit on you...thats $20 on the motors, and maybe $60 on a controller and battery pack...you won't get 4 reliable totally throttleable won't quit on you .10 cu in glo engines for $80....

So multi-engined scale is definitely better done electric. In fact most scale stuff is good on electric, except maybe those big WWII warbirds.

Likewise camera planes. Want to get rid of vibration? Shut the motor off and fold the prop?

Likewise thermal soaring - heck the sailplanes need ballast anyway, might as well put some battery in, and strap a motor on the front.

Also ultra slow lightweight stuff - far easier to do with a GWS system, and you can have a WWI biplane you can fly out of the backyard.

What you find is that you can fly more places and more often, and you don't burn gas getting to the club field.

Sure, if you like to do that, do it! You will need a runway for that ultra fast ducted fan jet anyway, or that giant scale B17.

But for pure 'charge it up and chuck it into the air and land in teh backyard' electric is where its at.

Its different. If, like me, you cut your teeth on stick and tissue and rubber bands, its how it used to be but with radio as well. Just for fun. Not trying to be fatser/louder/bigger/than the other guy - just the sheer fun of building things that fly.

AND if you do buy expensive, you can always swap packs and controllers and motors between models to get the best out of them - lets face it do you take 20 models down to fly? Nope. Just the 4 or 5 that suit the weather and how you feel on the day.

Reply to
The Natural Philosopher

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