Loop propeller?

[larryrose11]

While not RC, this is a fascinating design

https://www.mby.com/gear/sharrow-mx-1-tipless-propeller-110120

The Loop propeller nearly eliminated cavitation, slip, and has quite a gain in efficiency.

https://www.youtube.com/watch?v=X7pJqFgzXp4&t=1s

Real world test show a bit improvement in efficiency across the entire operating range.

[tbonemcniel]

That is extremely cool

[jkflow]

Yes, cool idea but hard to manufacture and therefore pricey. It does look like they are going mainstream. They are expensive, but will pay for themselves by saving fuel.

[fweasel]

I can only imagine what one would look like after striking debris in the water

[larryrose11]

The big market will be in the Ship size drives where fuel cost is everything.
I am willing to bet the this would be extremely useful for electric drive with Battery / Solar power.

On the RC side, what about the submerged drives, like an ECO?

[fweasel]

Real world hydrodynamic principals are most often thrown out the window in RC applications because of the insane scale speed and high RPM, however, I bet it would be much easier to cast miniature versions of these props and finish by hand vs. the full size version.

[srislash]

I found these awhile back and I think for a scale’ish FE they would work well. Should give good return on battery runtime. I sent it to our Ukrainian friend in hopes that he may investigate it but I think he has enough on the plate

[jkflow]

From all the reviews I've seen, at top speed the difference between standard and loop prop is negligible, but the efficiency gain in the typical cruising range is significant.
Won't add anything for FE type boats, don't think this will ever be an application for scale boats other than a curiosity item.

For weekend boating though, I'd gt one in a heartbeat, just need the boat first

[Johnc]

Sent my brother the link and he checked into them, got ahold of the company and lo and behold:
1st, need at least 150 horsepower engine
2nd, $500 down payment, $4500 balance due before delivery
3rd, up to a year on delivery

[jkflow]

Yes, expensive and popular. If you do a lot of cruising, it will pay for itself within a season. If you are just a weekend boater with a 5 min trip to a sandbar, it's not worth it.
Right boat, right motor and right amount of use to make it pay for itself.

[lohring]

Our propellers are surface piercing, ventilated props. Strength is an issue, even in model sizes. That's why our blades are wedge shaped. I doubt that the "loop" style propellers will work in any racing application.

Lohring Miller