Electric motor

[dheaton]

I am new to this forum and new to electrics. How does one go about finding out what motor will go with what plain?

I have a Carl Goldberg motor 550 Turbo 7.5V. Can anyone tell me about this motor?

[JetPlaneFlyer]

best read some of the 'sticky' posts in the beginners section: http://www.wattflyer.com/forums/forumdisplay.php?f=7

The motor sounds like some kind of old brushed type. Best use it as a paperweight and get yourself a modern brushless set up.

[dheaton]

Well it sure is heavy enough to use as a paper weight. I am just wondering if I have an old plane it might need the extra weight up front for cg ballance. No?

[JetPlaneFlyer]

Maybe, but you can always use a really big battery and fly for ages.

[dheaton]

Now that I am learning a bit more about electric motors I looked at my new Super Cub LP. it has a 480 brushed motor. So I guess I could always use my 550 for a backup motor yes? I would like to go brushless for this plane but wonder about the cg point.

Originally Posted by JetPlaneFlyer

Maybe, but you can always use a really big battery and fly for ages.

[Turner]

I think the 550 Turbo is a lot heavier than the stock SuperCub motor.

[ron_van_sommeren]

Originally Posted by dheaton

I am ... new to electrics. ...

My usual hit-and-run post ...

E-flight 101 by RCG member Ken Myers, will at least save you a ruined LiPo (or worse!), a burnt motor and a fried ESC:
The Ampeer
-> Electric Power Basics

followed by
The Ampeer
-> Everything youw wanted to know about e-flight (Ed Anderson)
Table of Contents

• Six Keys to Success for New Pilots
• Important Note About Motor and Propeller Safety
• The Mythical Best First Plane
• The AMA Park Pilot Program
• Things To Check On a Ready-To-Fly (RTF)
• What You Need To Know About Receivers
• What function goes on which stick?
• Battery Basics
• Amps Versus Volts Versus C
• Lithium Battery Chargers
• Balance chargers versus external balancers
• Extending Flight Times While Maintaining Balance (proper CG)
• Understanding the Electronic Speed Control (ESC)
• he Low Voltage Cutoff Feature (LVC) Of Your ESC
• The Role of the Battery Eliminator Circuit in Your ESC (BEC)
• Sizing Power Systems for Electric Airplanes
• Prop Versus Amps
• Why Consider a Gearbox?
• What Do the Kv Numbers On Motors Mean?
• Who Needs a Wattmeter/Power Meter?

[Dr Kiwi]

I think the 550 Turbo is a lot heavier than the stock SuperCub motor. [if that is a brushed 480 it's about 103g]

These are some specs I found:

The Kv is 2528Kv, Io = 2A, Rm = 0.085 ohms, 25A max current.

Goldberg Turbo 550: 9.3oz [ = 264g!!!!], 10-cells, 2.5:1 ratio, 10x7 prop, 25.5A, 73% efficiency: free in Goldberg kits, $16.50 gearbox

[kyleservicetech]

Originally Posted by dheaton

I am new to this forum and new to electrics. How does one go about finding out what motor will go with what plain?

I have a Carl Goldberg motor 550 Turbo 7.5V. Can anyone tell me about this motor?

Been there done that.

Those brushless motors are not even in the same ball park as even a cheap China import brushless motor. And, if you use that brush motor, you've got to find an ESC (Electronic Speed Control) that works with those brush type motors.

As an example, one model I built from scratch about 10 years ago has been powered with a high quality $$$$ brush type Astroflight geared 40 motor. That motor was replaced with an Astroflight geared brushless motor with the same 21 cell Nicad pack. Both motors ran a 13X10 propeller. The brushless motor increased flying time by about 40%, and at the same time, increased power output.

That model is now flying with a $$$$ Hacker A50-12S with a 15X10 prop and a LiPo type battery (FYI its a 6S2P A123 pack). The Hacker motor turns the 15 inch prop at about 1000 RPM faster than the Astroflight turned the 13 inch prop, that is a substantial increase in power.

And going from that Astroflight motor and its three minute flights, that same model now flys for 7 minutes. And, nearly one pound of dead weight was eliminated by going from the Astro motor and Nicads to the Hacker and its A123 cells.

The model went from a 100 foot take off run with the Astro motor to 25 feet with the Hacker, and now has the ability to fly straight up out of sight.

As other's have indicated, those brush type motors are now kind of a paperweight.

[Dr Kiwi]

Denny,

Minor correction needed:

"As other's have indicated, those brushed motors are now kind of a paperweight".

[kyleservicetech]

Originally Posted by Dr Kiwi

Denny,

Minor correction needed:

"As other's have indicated, those brushed motors are now kind of a paperweight".

Oops
Thanks, my fingers are so used to typing "brushless"

[CHELLIE]

Originally Posted by dheaton

I am new to this forum and new to electrics. How does one go about finding out what motor will go with what plain?

I have a Carl Goldberg motor 550 Turbo 7.5V. Can anyone tell me about this motor?

Hi when Starting out with a RC E Power System, its easier to buy a power system based on the weight of the plane and use Thrust and not Watts as a Gauge, Watts can be deceiving when starting out, you can use a lot of Watts with a high kv motor and a small prop and not have any thrust, and you can have a lot of thrust with a low KV motor and a big prop and not draw a lot of Watts, its confusing at first, thats why I say use thrust as a measurement to get a power system with, as you will always know what thrust you have and what your plane weights, Look at the motor pages at Heads up Rc, Jeff gives thrust oz with his power systems and lets you know what prop, esc and lipo to use, Jeff has taken the guess work out of trying to get a proper power system for your plane, always get a power system that has the thrust that equalls the planes weight, its the best way to go, here is an example of Heads Up Rc Motor page, also you can Email Jeff for a power system recomendation, tell Jeff that Chellie sent you

here is a power system for a plane that weighs 18 to 48oz,

http://www.headsuprc.com/servlet/the...h-11%29/Detail

The Firepower 480 Sportweighs less than a 400 speed brushed/geared motor, and it can be used in many applications calling for a 400 to 600 brushed motor. Keep in mind that the Firepower 480 Sport is a 35mm (1.4") diameter motor, so you'll want to be sure you have room to mount it on your model. Should you need to use a 28mm diameter motor, take a look at the Firepower 450 Sport (2836-11) and see if that will do the trick for you. And if you need a brushless motor that is the same size and weight as the Firepower 480 Sport, but uses smaller propellers and provides higher speeds, please check out the Firepower 480 Speed (3530-14).
The Firepower 480 Sport comes with 3.5mm male connectors installed, and female connectors are included.
MOUNTING OPTIONS: TheFirepower 480 Sportcan be mounted in front of a firewall using the 3500 series 'X' mount and the 3500 series rotor end prop adapter, which are included with the motor. You can also mount it behind a firewall, and a 4mm prop adapter can be purchased to mount a prop on the motor shaft. The picture below shows the motor with the 'X' mount and rotor end prop adapter attached.

Propeller test data for the Firepower 480 Sportusing 3-cell Lipo batteries:
It's a good idea to balance all propellers with a Propeller Balancer before using them on this motor.
Rotating propellers are dangerous. Please stay clear of prop and wear eye protection.
APC 10 x 5E: 39 oz thrust @ 23 amps
GWS DD1060: 40 oz thrust @ 22 amps
10 x 6 folding: 35 oz thrust @ 18 amps

APC 9 x 4.5E: 35 oz thrust @ 18 amps

GWS 9050: 36 oz thrust @ 18 amps

GWS 9050x3 3-blade: 38 oz thrust @ 21 amps

APC 9 x 6E: 36 oz thrust @ 21 amps
GWS 9075: 32 oz thrust @ 25 amps

Please be aware that the battery used can make a tremendous amount of difference in the performance of brushless motors. The above data was obtained using batteries in good condition that were fully charged. Thrust and amp draw may be less with the use of batteries rated at lower amp output, and slightly more using batteries rated for higher amp output. Other factors, such as ESC timing and variations in actual motor KV can affect the performance of brushless motors as well. We recommend the use of a Watt Meter to test the current draw of your particular power system, especially if you plan to use a prop that pushes the motor near it's maximum amp rating.

Firepower 480 Sport Specifications:
Weight = 2.6 ounces (74 grams)
Diameter = 1.4 inch (35 mm)
Motor length = 1.2 inch (30 mm)
Shaft = 4 mm x 0.7 inch (18 mm)
Voltage = 7.2 - 13.0
Current = 25 amps or 260 watts maximum for 30 seconds.
KV = 1100
Mounting holes are spaced 19mm and 25mm (measured across the center of the motor) and are tapped for 3mm screws.

[CHELLIE]

to check the thrust and weight on your completed plane, use a fishing scale, set you plane on the ground attach the scale to the rear of the plane and power up you can check the AUW / weight of the plane too by just hanging the plane with the scale and reading the weight.

EBay has a nice fish scale for a few Dollars, its Watt I use

http://www.ebay.com/itm/20g-40Kg-Dig...item3373b1ac77