Electrical Can Electric Motors Revolutionize Flying Craft Design?

[LC53]

TL;DR Summary

building a flying craft.

I am not sure if I am in the right place... I am, I guess for all intent and propose, a "dream" guy. I come up with something and cannot get it out of my head until I have explored all the possibilities. About 7 years ago, I came up with a thought about a "flying vehicle", Prop driven without all the "bells and whistles" that the big companys' are putting into it.

I was going to use a 4 cyl honda 750cc engine as the power house. But recently taking with a machinists, he suggested I research electric engines, one on each prop. instead of using drive shaft and gears. He believes with todays' technology allot of improvements have been made in the electric motor industry and well as the power supply to drive such engines would save allot of the weight issues.

The problem is: Where to start?? what size electric motor(s) Power, RPM??

I have three props to drive, one in the rear, 48" and two on swivel axis to drive. steer and additional lift, these are 36".

So, the question is, where to go to find such information. Any help in direction would be appreciated. Thanks... Ken (aka LC53)

 

[berkeman]

Welcome to the PF.

Can you post a few more details, and maybe some images of similar craft? I assume you want VTOL capability, right? How far do you want to be able to fly it?

 

[LC53]

TY for your reply Berkeman, Yes VTOL is the goal. Looking at my avatar might give you a clue to the direction I am looking at, but instead of the 'motorcycle' style, I am looking at more of the siting and lying back position. This will give me the opportunity to use legs to steer the craft. Other controls will be on the hand controls, similar to the throttle on a bike. Originally the clutch and throttle would be the same with a toe shiftier on one of the foot platforms, again like a bike.

But with the idea of gaining or I should say losing the weight of the motorcycle engine by using electric motors, I will be able to do away with clutch, gear shiftier and the gear boxes used in transferring the drive to each prop. The two 36" props on the front will swivel, allowing me to control forward and reverse motion and turning, while the rear 48" will be for lift and some forward thrust. The body/frame will be of a high grade aluminum and more like a go kart than a motorcycle.

So, by changing this, powerhouse, and moving into the electric motors, what should I be looking for as far as the electric motors? I have decided/thought about setting up a lab experiment with some motors I have. Hook up a prop and test the props to decide which direction I need to go in. ie: size motors, RPM and hp. any thoughts? Forgot to answer one of your questions...how far... how far can I go, the further the better.

 

[BillTre]

I like your approach. Sounds like the Wright brothers.

My father in law used to build and fly ultra-lights.
He was quit skilled mechanically.
He was in So. Cal. (LA area) and he had a group of ultra-light fliers that got together out in the desert when the weather was good. Many of them also were quite smart about things associated with flying ultra-lights. Worked for him.
There might be some similar group for VTOL groups. Or there might be some VTOL interest in an Ultra-light group.
That would be a set of people who shared the same design issues.

 

[LC53]

Thanks!

 

[berkeman]

But with the idea of gaining or I should say losing the weight of the motorcycle engine by using electric motors,

Keep in mind that for gas powered aircraft, you have the weight of the engine and the weight of the gas/fuel. For a battery powered aircraft, you have the weight of the electric motors and the weight of the batteries. Which set do you think weighs less and why?

Here's a useful (but long) thread in the ME forum about battery powered aircraft and some design considerations...

https://www.physicsforums.com/threads/question-about-electric-aircraft-propulsion.973920/
And I did a Google Images search on personal electric aircraft, and got some good hits. Do that search and look through some examples of designs, and think about why they are using those designs (like the number of vertical rotors...).

 

[hutchphd]

A few things seem obvious to me:

1. You should be playing with RC quadcopters (you will learn much)
2. The use of electric motors allows distributed lift because most of the weight is shifted to the batteries and the motors are relatively light weight.
   • I would sure like to have a redundant system where any single point failure would not kill me (maybe six lift motors where any three could keep you from disaster?)​
   • differential thrust allows you do all the control without any mechanical motion of the members under lifting load. Big rotating joints are heavy and electronics are not. Also moving rotating objects produces large and often unwanted precessional forces.​
   • If all thrust assemblies are similar the construction gets very much simpler (maybe an hexagonal configuration)​

The Kitty Hawk machine @berkeman looks fabulous and I want one! Hope this goes well.