Carbon (or other than wood) props option?


#1

Hi there. Is there any plans to include as an option carbon props?
I remember when I switched from wood to carbon in a 2 strokes and the difference was huge. It allowed me to run a larger yet lighter prop without feeling any aceleration time decrease. But I did change the engine prop ratio to keep the blade tips aerodinamically happy…At the end I had 7 kg more of thurst with the new set up, running at the same engine RPM´s. Tested the same day with maybe one hour difference.
But I have no clue how this will work in this smaller - direct dirve - 4 props configuration.
Or maybe something like those plastic or nylon props used in current drones?
Just thinking loud. Sorry… :slight_smile:


#2

I’ve got a line on a couple carbon prop vendors, but haven’t yet found anything stock with the same pitch. All the counter rotating props are made for drones (static thrust vs dynamic) so a bit more searching and/or some custom props will be needed


#3

On the subject of props, CW & CCW matched pairs, in a different forum, e-PPG.com, I was put onto vrtule-fiala.cz/en/electro-e3-propellers-49 by Simon. They do some very nice matched wooden props. The two I bought came in very cheap and good quality, they let me pay via PayPal. Made and shipped to me in Australia pretty quickly too. For very few dollars it would be fun to try a few different pitch combinations.


#4

I think that when switching from wood to carbon, having the increased strength of the material, we can not just copy the pitch of the wood props but also test new profiles/pitch combination.
Also a lighter (less mass) prop will be able to spin faster and, again will make us think about increase the pitch…
Tons of fun.!!


#5

Prop weight really just drives inertia, and therefore responsiveness. We’ve already had to slow down the response since there is already so much torque :).

I am, however, excited about trying some other profiles!


#6

Hey all,
I have previous contact with Lonnie prince from prince aircraft, on designing some carbon blades for an eppg. (Never happened, but this is prolly better, lol) Originally my intention was single blade, and from my research their “p-tip” prop really benefits with larger props and speed, but I could send him our specs and see what he says. Also I would have to see if it’s a c.f. wood wrap or not :confused:
I pulled this from the specs request portion of the email, if you guys like, and with the info, I could get it sent over to him?

“To design a propeller we will need the HP, Propeller RPM, and Airspeed, all in the full throttle level flight condition.”

Cheers,
Shorts


#7

I would definitely be interested if the p-tip is truly as he says “a pronounced reduction in propeller noise”. The more quiet I can be in my area the better.
I do not know the answers to those specs though.


#8

I agree especially going with multiple blades vs a single it can become a factor… but is this noise and list of benefits better then gas? I think so!
@Pdwhite if there’s an interest and you’re willing to test, would be able to get these specs? I could follow up and see what comes of it. Plus were all local :wink:


#9

I contacted powerfin in the usa when I did my swap some years ago and they were able to sell me their smaller diameter prop and it fitted just in the border of my single prop project. So I don think (Hopefully I will be wrong…) that a full size aircraft prop manufacturer will be able to provide such a small prop.
Maybe we should try with drones / RC props manufacturer… And also we just need one of each possible variant to compare them on the bench. That will cut down de “research and development” cost wich is sweeet…


#10

Yeah I did consider that. Only because we’ve talked about his past experience with ppg props, and understanding of it (where as I’m lacking) did this grab my interest. But luckily an email is free, and my first request would simply ask if he sees its worth the time/ have a possible benefit.