Electric flyer questions

What is the difference between a 370 and a 480 motor? Or even the various classes of motors?

What does the gear ratio mean? Like a 3.67:1 (370) and 2.50:1 (480).

what is the difference between a 4G/4D/6D motor?

Thanks...

Reply to
Omega
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Reply to
The Natural Philosopher

I heard one time that 370 and 480 had to do with the shaft size. I have also heard it had to do with the can size. The gear ratio part is easy: the motor shaft makes 3.67 revolutions for every revolution the prop shaft makes. A 4D, I think, is a speed 400 motor with no gearing. Directly driving the prop. A 4G would be a speed 400 motor with a gear box, etc. 6D would be a

600 sized direct drive motor. I am probably wrong on several points and have no doubt that somebody will gleefully correct them. I fly glow anyway, not electric with the exceptions of my Wingo and Zagi. At least THIS thread is On Topic.
Reply to
Fubar of The HillPeople

The larger the number the physically larger the motor.

3.67:1 means the motor turns over 3.67 times for every 1 turn of the prop shaft.

Not sure where you got these numbers from. GWS uses letters to identify gear ratios. brushless motors use 4T, 5T, 6T etc to describe turns of wire inside the motor. The fewer turns the higher the RPM per volt.

Lurk at RC Groups or Ezone for a while and you'll learn all you need to know.

remove my-wife to reply :-)

Reply to
Icrashrc

Good such a treat started. now i can ask this question .

take by example a speed 400 motor from 10 different brands how do i know wich has the most power ? I do car races also and from every decent motor we know how many winds there are on the armature. so an motor with low winds has more power (RPM) over an motor with more winds (less rmp, more torque ) why do the airplainmotors dont list there winds ???

TM

Reply to
dingo

Most 'speed 400' can motors are all made by the same manufacturer. There is 3 different winds available. generally expressed as 6 volt and 7.2 volt. 4.8 volt is hard to find and not widely used.

remove my-wife to reply :-)

Reply to
Icrashrc

They are broadly all the same. Ther aremionor variatins in windings, so they develop teh same power at different voltages, but tey are all mabuchi 380 class motors under the label.

They list voltage instead.

Besides, in planes we don't all run off the same pack voltages. A 6v speed 400 on 7 cells is almost identical in every respect to a 7.2v motor on 10 cells. Except the voltage/current are diferent, but power and RPM and torque are the same.

Reply to
The Natural Philosopher

Thre are a couple of other winds out there as wel, but in general, you are correct.

4.8v is a good choice for 7 cells or 2s LIPO, if geared.

Reply to
The Natural Philosopher

Speed 400 motors, and all cheap can motors in general, are special cases. For the most part, they're all made in the same factory, at the same time. They're manufactured for installation into generic consumer products, not airplanes. "Manufacutrer" A's "Turbo 550" would be the same as "Manufacturer" B's "Speed 600." Any motor with a 380 or 400 motor designation will be the same as well.

How do you know which has the most power? That's not how electrics work. Motors have ZERO power in and of themselves. Motors only handle power; they don't produce it. You dictate how much power a motor "has" with the battery and propeller/gearbox load.

I guess in the most simplistic sense, the 400 motor with the lowest V-rating would "have the most power," but ONLY IF you keep the same exact battery and propeller for all motors in the test.

Why? Winds are meaningless and useless when you talk about airplane motors. Airplane motors are all different shapes and sizes, where car motors all have the same physical dimensions across the board. Winds are only useful when comparing motors of the same physical dimensions.

A 12-turn motor that's 2" in diameter and 3" long won't perform the same as a 12-turn motor that's 1" in diameter and 2" long.

Reply to
Mathew Kirsch

Size does matter true, but expect all 400motors has the same size ?? not just like all 600 and 540 and so on.

TM

Reply to
dingo

does this also means that a speed400-4,8V on 4 cells will perform eqeal to an speed400-8.4 on 7 cells ??

Reply to
dingo

When you're talking about the cheap can motors, yes, all 380 and 400 motors will be the same physical size.

Reply to
Mathew Kirsch

Just about, yes. If you pick the voltage that gives the same RPM, then the motors will perform identically.

windings ONLY affect the voltage the motor will run at best, not its ultimate power or efficiency.

Reply to
The Natural Philosopher

Get on E-Zone, register, go to beginners and other discussion groups, get all the info you need. Speed 400 motors come in 6 volt and 7.2 volt versions. A 6-volt motor works best on 7 nicads ( 8.4 volts) or 8 NiMh cells (9.6 volts). A 7.2 volt works best on one more cell of each type. Most of us use 6-volt motors for lighter battery weight. A 7.2 volt motor won't provide as much thrust on a 7 or 8 cell pack as a 6 volt rated motor. I don't what a 7.2 volt motor would be suited for in model planes.

Gary Gullikson

Reply to
garyg

actually they come in 4.8v (race) the MFA rocket 400, the 6v and the

7,2v versions.

Actually it works best on about 14-20v Power and efficiency keep going up till the brushes start to skkip on teh commutatir, at which point it rapidly burns out.

About 20-24v actually.

Its the perfect choice for direct drive at the usual crap efficiency a DD motor gives, on 3s LIPO.

Geared, the 4.8v race motors are perfect on 2s LIPO the 6v on 3s LIPO and the 7.2v on 4s LIPO, pulling upwards of 30K shaft RPM at which point they will all take about 100W and put out about 60W shaft power.

Pretty much .049 power or a good 1cc diesel.

Reply to
The Natural Philosopher

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