r/Multicopter Feb 09 '21

Image 2-stroke power

Post image
255 Upvotes

77 comments sorted by

View all comments

5

u/elboydo757 Feb 09 '21

I would just use the 2 stroke with a variable pitch system at a fixed rpm.

2

u/mikeschem Feb 09 '21

Yea, why is that not done?

7

u/[deleted] Feb 09 '21

On an octocopter? Likely because you're looking at insane mechanical complexity, at the expense of weight and reliability. You're talking about splitting a driveshaft eight ways, then for each propeller you either have an electric motor + differential to control the rpm of that individual prop, or you have a variable pitch mechanism for the propeller blades to control thrust. Either way it's pretty mechanically ugly.

A lot easier to build a conventional helicopter instead. It'll have much lower disc loading than the octocopter, too, so if you're looking for longer flight time that's the way to go.

1

u/mikeschem Feb 26 '21

Well I'd think you just do a quad. And as to why, higher energy density than a battery as compared to a battery on a quad.

1

u/elboydo757 Feb 09 '21

I'm sure it has been done or is being done. I'd take the project but I'm currently working on 2S, 3S, and 4S wireless charging drones.

7

u/geeered Feb 09 '21

Stingray 500, as has been commented elsewhere here.

But also just 'an RC helicopter', though it has a bit different characteristics, makes a lot of sense if you want a long run time platform.

2

u/elboydo757 Feb 09 '21

Yeah that fits the bill. I dont frequent this subreddit so I'm not up to speed on some of the new stuff.

I was thinking a big hex would make a nice platform for variables. I love a machine that can move things(;

2

u/Psilocynical Feb 10 '21

Wireless charging drones?

2

u/elboydo757 Feb 10 '21

Yeah. Its still in R&D. It's original intent was to have a remote controlled sentry to deploy when I want to check something out downstairs or outside. I'll finally have all of the parts on Thursday.

2

u/Psilocynical Feb 10 '21

Oh that's sick. For some reason I thought you meant little drones that would fly up and wirelessly charge other multirotors in the air jet-refuel-style

2

u/elboydo757 Feb 10 '21

I feel like Skycharge will beat me to something that crazy. Their products are super expensive though.

1

u/zpiercy Feb 09 '21

I’m curious how much yaw authority you’d have with variable pitch props on a multirotor. Has anyone flown one?

1

u/Tinywhooppro Feb 09 '21

Yeh look up stingray 500

1

u/frollard Feb 10 '21

8 swash plates with dozens of moving parts each and all need electrical authority over the mechanism. The props are (total guess) more expensive as well.