electric clutches

[RotoPlane]

Ah so....good idea. Thank you Vance!

[WHY]

Hi Martin

While not extremely popular here in the States, in Asia and Europe electric scooters and electric bikes are very popular. Have an electric bike my self with the "hub motor" on the bike, VERY HAPPY WITH IT.

I am very glad to see this thread gather so much attention from people with experience in both fields, hydrualic and electric. I feel that both systems are very practical, it just depends more on the machine as to which one is the choice.

My ambition is to see takeoff runs in the 300 ft range as an everyday takeoff and 200 ft as "special" . If our sport is going to become truly competitive with other types of aircraft, we have got to start "walking our talk" and we are always "talking short takeoff and landing, well, we got half of it .

Tony

[WHY]

Just a side comment, those interested in the hydrualic style pre-rotor, RotoPlane in post # 17 gave a really good source for the electric clutches.

Tony

[Vance]

Technical Specifications:
Motor Diameter: 3-1/2"
Shaft Diameter: 8mm
KV: 130 Kv
Voltage Range: 37V
Max Amperage: 90 Amps

Weight: 48 oz.

Maybe something like this would make a fun prerotator motor.

You could use two and still be lighter than most electirc starters.

A small batter pack would run it until you could charge them back up.

Thank you, Vance

[WHY]

Check out possible E-bay buy, on Ogura clutch E-bay # 230820046001 $85

Tony

[CLS447]

Ercoupe and Cessna 150, 152, 172, 140, Aeronca,7ac, Citabria,Chief,Piper PA11,PA12


Tony, do you own all of these now ? Do you have a flying gyro now ?

Just curious ?

[WHY]

Hi Chris,

Just owned the Ercoupe and Cessna 150, sold the Ercoupe a few years ago. Soloed the rest. Building a tractor gyro.

Tony

[Alan_Cheatham]

Originally Posted by themonarch

Hydraulic driven pre rotators are an excepted method. By reading this post, it seems that there are desires for enhancemant. This a good thing. May I ask all of you for your opinion of the alternative, that being electrically powered pre rotators?

Larry Neal is nearing his release to the public of an new design electric powered pre rotator system. Mr. Neal states that his latest system will spin to flight rpm. Thats how he put it to me in a recent email. I could have asked Larry with more detailed and specific questions about his system, yet have decided to wait and view the merchandise.

Someone at Mentone stated that he could be using an electric motor as seen on scooters. I did not know that there were electrically driven scooters. I am curious. Would the any reader here bother to shed some light on this concept as applied to pre rotators?

I've seen Larry's system and he's using the newer breed of electric motors, controllers and Lithium batteries, with this you can put 20 hp to the rotor and that will get you to flight rpm. This is far more hp than your typical electric starter motor prerotator can deliver and gives far greater performance but also comes with it's own set of pros and cons, mainly cost, durability and risks of Lithium batteries.

For detailed information on Larry's system I defer to Larry, when he's ready.

.

[cbonnerup]

Technical Specifications:
Motor Diameter: 3-1/2"
Shaft Diameter: 8mm
KV: 130 Kv
Voltage Range: 37V
Max Amperage: 90 Amps

Weight: 48 oz.

Maybe something like this would make a fun prerotator motor.

You could use two and still be lighter than most electirc starters.

A small batter pack would run it until you could charge them back up.

Thank you, Vance

VERY NICE Vance,
2 would give you almost 9 HP. Do you happen to know what the 130 KV is referring to?

The main 'problem' with MOST current electric motors is that they 'like' to run at full power or not at all unless the controller is wasting a lot of the power. This means you have to switch the power off / on (called pulse-width-modulation) at very high speed to control motor torque below rated max. Rapid switching of high currents produces nasty side effects on other electronics nearby. It can be designed out by careful design, but IMHO is not an easy or cheap task. Poly-phase (3 or greater) motors are better controlled in this manner.
There are some unique designs of electric motors in the works, and we will see if someone can offer a 12V (or 24V) motor at 10 HP output; that would be 625 (or 312) amps at max HP. The key to high power small motors is operating at high voltage and low current; but high voltage presents other problems. Again not impossible; these issues can and will be worked out.

When 'they' develop room-temp superconducting wire it will make fusion power unnecessary - at least for a while.

Regards,
Chris

[Vance]

Originally Posted by cbonnerup

[U]

VERY NICE Vance,
2 would give you almost 9 HP. Do you happen to know what the 130 KV is referring to?

Chris

KV=Rpm/V

This particular one is 37 volts and uses a controller something like this one.

Technical Specifications:
PHOENIX ICE2 HV 160 Specs:
• Length: 3.99" (99mm)
• Width: 1.5" (38.1mm)
• Height: .9" (22.9mm)
• Weight: 2.3 oz* (65.2g)*
• Max amps: 160 amps**
• Max volts: 50 volts,12s LiPo,36 cells NiCad/NiMh

It can be driven by less than two pounds of Lithium Polymer batteries.

I suspect that two would probably drive a 30 foot rotor to 150 rpm.

The even come with little gearboxes if you want or plug them into a car starter bendix and gearbox..

Thank you, Vance

[WHY]

The voltage/current thing is the present nemisis of the electric pre-rotor for larger rotors, so for larger rotors, it is mainly going to be hydrualic or mechanical. 12 volt electric is still a good option though for the smaller rotors, I think it can easily reach the 200 to 250 rpm range. We just need to stir up the minds and imaginations of the guys "in the basement and out in the garage" !!! Just look what has come up in this thread in the last week or so

Tony

Tony