Considering how Helicopters work, would it be possible to create a personal helicopter using a lawnmower engine? Say a regular 5 or 10HP engine.
It would use these principles to get it to work:



The shaft of the spinning blade of a lawnmower could be turned into a gear, and thus, with a gear welded onto a pole with blades on the top, it would spin, causing lift. I just want to know if it can be done, because my great uncle created a helicopter from a snowmobile engine....

Hmmm, I have no real knowledge on this, but I would imagine a lawn mower engine might not be powerful enough to get the large blade you'd need spinning fast enough... then again I'm just takin a poke at it


I think that's really cool that you're uncle made one with a snow mobile engine. Again, one of those is intended to power a bit more than a mower blade spinning.

Exactly. If a lawn-mower engine could power uplift, then your lawn mower would incedently hover when in use.

^ Stand-on lawn mower hover craft anyone?

No, it would not. The mower blades are pointed the same ways causing a neutral stance, but still kicks out grass
And also the blades are FAR too small to lift a 30lb aluminum casing plus a 50lb motor!

I used to have plans to build a one man gyrocopter with chainsaw engines.

My Uncle once designed and built a bi-winged ultralight aircraft that he powered using a chainsaw engine... at least the engine looked like it was from a chainsaw it was very small. It had a single wooden prop on it. I'm not sure what the tourque outputs are of a 2 cycle engine vs. a 4 cycle engine... I wonder if that makes a difference.

Black&Decker used to sell a hovering lawnmower in the 80s. I fail to see how 5HP are capable of lifting a 90 pound human by propelling air.

different story, while a real chopper lifts from motor power a gyro lift comes from speed. A small airplane has been build with small engines, google Cri-Cri

If you're talking about a real helicopter, here are the requirements:
Helicopters are "rotary winged aircraft", meaning that the lift does NOT come from blowing air downwards, it comes from the blades being airfoils. The rotor is, therefore, a set of spinning wings. Note that the rotor rpm is necessarily slow, since the rotor disk (the circular pattern followed by the blades) is quite large. The H-3 Sikorsky, for instance, had a wingspan of 72 ft, which limited the rotor speed to 204 rpm before blade stall at top airspeed. In short, the blade tips exceed mach 1, causing major control problems and loss of lift. With smaller choppers, the blade diameter is smaller allowing higher rotor speeds.

As to horsepower, you need enough power to provide the rotor speed. As you increase lift by changing angle of attack, you increase horsepower requirements. The H3 delivered 2500 shaft horsepower from two T58 turboshaft engines. Smaller birds require less, of course. Figure that to have any real altitude, a one person craft will require at least 50 hp, with as light an engine as possible. Increase altitude, increase hp requirements, also true with speed.

However. There are ways to cause lift with smaller hp requirements. Those ideas have been largely ignored and misunderstood. The concept is to use a lower hp engine to spin a fan that simply moves air over a foil to cause the lift. Control of these is difficult at best, and there is some degree of difficulty associated with winds. Lift, however, can be generated with much smaller blowers/hp than with a standard airfoil such as rotor wings or fixed wings. If interested, I can supply a website with an experimental saucer shaped device using this method.

A lawn mower motor is designed to provide enough force to cut the grass not lift a human being.
If you try using it to lift a mass like that it is likely to draw huge amounts of current and burn out.

First you need to design your helicopter.
This is more than simply drawing a picture as you need to take into consideration the weight it is to lift, the stress's all the parts of the helicopter are going to be put under and the materials you are going to use to cope with these stress's.

Then you need to over engineer your helicopter so it can cope with forces 40 times what you have calaculated. That way you are covered by anything you may have missed.

Next you need your motor, blades and tail rotor for stabiloity. Alwso your motor will need a power supply.

All in all building a helicopter would be fairly easy but safety is paramount so don't attempt it unless you are a professional engineers and have experience of what you're doing.

Yes, it can be done. It's been done - the technology is about sixty or seventy years old now.

Initially, as I understand it the techinque was invented by Nagler-Rolz, intended initially for a strap-on back pack to fly individual German soldieers over battlefield obsticals. After WWII the US experimented with this but abondoned it due to the hazards to the individual.

Home bult helicopter kits using this propulstion method were and still are available for sale under the name of "Prop Copter". The machine uses twin (as in identical) 5HP gasoline lawn mowers.

At present I'm looking for a FULL and COMPLETE plan set for the older varient, once advertised as "Prop Kopter" - note the difference in spelling from the above.

If any of you come across such a plan set and/or the entire kit along with the plan set it's be appreciated if you were to let me know.

tyc