Simple, really. Comes in a roll, and is basically a strip that you cut to length to suit your fan blades. It's got a very soft leading edge to minimise impact injuries.

The "back" of this strip has a lengthways slit, so that you cut the strip to length, then just push it onto the leading edge of the fan blade. The elasticity of the sillicone allows it to "clamp" to the fan blade rather tightly - so it doesn't come off under centripetal force. Comes in different slit aperatures for different fan blade thicknesses, although I would think most fan blades are in the 1-1.5mm range. Yes it will reduce fan efficiency. Future versions will have careful tapers to reduce turbulence at the leading edge.

Lastly, it's cut-to-length, so if your fan becomes unballanced, just trim the strips to suit.
-- Custardguts, Dec 02 2008

safe fan Safe_20fan
shameless self promotion [xaviergisz, Dec 23 2008]

The hand's fine, by the way - no broken bones apparently.
-- Custardguts, Dec 02 2008


One word: natural selection.
-- MaxwellBuchanan, Dec 02 2008


/Yes it will reduce fan efficiency/

Does it say that on the box?
-- Texticle, Dec 03 2008


One could easily make this out of pipe insulation. This comes as a foam tube with a slit along the side.
-- bungston, Dec 03 2008


//Does it say that on the box?//

No, it's sold off the roll at the hardware store. Why do you ask?

//make this out of pipe insulation// - I thought of that, but pipe insulation may well be large enough to totally negate the pitch of the blade - I'd guess that a 20mm or more diameter on the leading edge on a ceiling fan might well stop it from pushing air at all. Insulation is nice and squishy, though. New idea - "NERF foam replaceable fan blades"

//natural selection// - It's a fair cop.
-- Custardguts, Dec 03 2008


Oooohhh.. how about wiffle bats instead of fan blades, completely? Huh, I could see tossing things up there all day, just to see how far they go.

Shucks, just looked over and read your NERF idea. Nice one.
-- Lily-Jar Nemesis, Dec 03 2008


Ceiling fan blades tend to be inefficient anyway. They should be rather like aeroplane propellors, but thin to save on materials and because they don't need enormous strength. If your edging were teardrop shaped and applied to a well designed blade the efficiency could still be higher than that of most blades.
-- spidermother, Dec 03 2008


I think that you are confusing thrust with air circulation. The fan converts laminar flow to axial flow producing minimal thrust or vice versa depending on the season. A prop is designed to produce minimal axial flow and thus maximal thrust. Different purpose, different blade profile. Ceiling fans are relatively efficient for their speed and purpose and an airplane prop would not be more efficient in that setting. That being said, some "modern" fans have swoopy prop-like designs but this is actually a less efficient design for circulating air in a conventional installation. Some special cases such as atria and vaulted rooms can utilize a more linear flow pattern but this is the rare case.
-- WcW, Dec 03 2008


//centripetal force// wouldn't make it come off, centrifugal force would though...

Great idea for saving heads, arms, etc. Could use small jelly rubber (~10mm)which already has a hole down the middle & just needs to be split? Could be stuck on with thin double-sided tape?
-- superjohn, Dec 03 2008


// //centripetal force// wouldn't make it come off, centrifugal force would though... //

-nice pickup. I'll leave it there so as to validate your anno.
-- Custardguts, Dec 03 2008


[superjohn] That's kind of what I meant; they're not optimised for thrust, so decreasing their efficiency won't matter much.

I mostly just find their inbetweenness aesthetically unpleasing. If they were designed to stir the air, they should be like oars; if to produce thrust, like propellors.
-- spidermother, Dec 23 2008


//One word: natural selection//
That's two words.
-- coprocephalous, Dec 23 2008



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