'Feel' of different blades.

Resasi

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London/ Kilifi Kenya
Aircraft
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. GT-VX1&2, Pax ArrowCopter
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100+ gyro, 16,000+ other
Was able to try two sets of different blades at the end of this week. I normally fly the Bensen with 23' Rotor Hawks and find them a mild mannered blade but will Flap/Sail if I am careless. On a flat calm day they can be a bit tiresome to spin-up, haven't got a pre-rotator. I do like the combo of the 532, 23 RH's and a 4 blade 52''Arplast and it is a nimble responsive little machine. Just had two 5gall aluminum fuel tanks made, they do feel quite solid/heavy. Interesting to see how much performance will be lost with the extra weight of the fuel and tanks.

I then went for a ride in a friends Cricket with a pre-rotator and 23' Dragon Wings. They seem a bit more responsive than the RH's and definitely will flap/sail much more easily if not watched. The prerotator was certainly nice to have. I don't know how much difference there was in the two machines weights, the Cricket has a big fuel tank, prerotator and a pod and possibly heavier but close, and it seemed to me the DW's definitely had more oomph and performance in them. Landings seemed fine didn't notice a lot of difference there.

Next was a Bensen with 23' McCutcheon Skywheels. They seemed a lot more solid and stable blade and felt as though they would be more tolerant than either of the other two in regard to blade sail/flap but since I wasn't inclined to test that part, didn't even try. The lift off was quick and it seemed to me that I could exercise a more precise speed control with these rotors. Landings could also be precise and the blades had a lot of inertia. Didn't look at the performance side of things as we were keeping the hops and runs low as it hadn't flown for a while. The VW engine/prop combo didn't seem as responsive as the Rotax's, and I am sorry I don't know what prop it was. Very pretty, big broad wooden two bladed job that would look good on a wall with a clock in it.

Unless one flies them back to back it is hard to compare so it was nice to have this opportunity to do so.
 
Hey Leigh,
Nice to try different sets of rotors.
Dragon Wings are the best bang for your buck and out preform every rotor I've ever flown. Have to have a prerotator unless your young and strong.
Sky wheels are also nice,since they hand start and are great for a cruise.But in gusty weather can be a bit of a ride.
I've never flown the NEW Sport Rotors so can't say much about them, the old style were not very impresive though.
Good luck with your testing ,have fun and be safe.
 
I just put a set of 25' DW on the 670 rotax gyro and without a pre-rotator I could not get them up to speed so I put the old fleck blades back on until I get a pre-rotator.

my 24'4" fleck bloades weigh 80 pounds the 25" DW about 60.
 
Thanks Jake, yes we put Ernie's blades on the Hornet. Didn't manage to get but a few hours on it but they do very nicely and with Nicolas's prerotator they spun up nicely and she felt pretty good.

Brent that's a blade I have not heard or come across. Who makes Fleck blades?

I've had a little time with the Magni blades even less with the MT blades, but then they were much heavier two seaters. Felt a bit like GA aircraft, but nice and stable if that is what you want.

I would have to say that I probably enjoy the agility of the single's and just being able to horse them around. That's where my buzz comes from.
 
Prerotators

Prerotators

Brent,

I thought you would have gotten tired by now with no pre rotator thing.

Maybe you can try the D.W's when you can catch someone else's prop blast.

J
 
Thanks Brent, haven't yet come across any of them. Be interested to try them when an opportunity rises.

Catching prop wash is always handy when the wind is down Jonathon, always on the look-out for a freebie then.

Been at an airfield when out on a cross country when there wasn't a breath of wind. I had to explain to the tower operator that I might have to taxi up and down for a bit to try and get the blades up. Luckily it was a PPO (prior permission only) airfield and he knew there would be no traffic coming in so he invited me to help myself to the runway.

I was still not very experienced and it took me two lengths and the onset of blade sail/flap at least a couple of times by being impatient before the blades began to get up to speed. I then was able to turn round and finally request TO clearance.

He had obviously been highly entertained by all the getting out of harness and seat to pat up, hop back in and taxi slowly forward...then repeat, told me to come back anytime it was slack and calm!!!
 
Fleck, Vortec and Rotorhawk are all the same if I’m not mistaken.

Extruded 8H12 blades.

Originally, Rotorhawks were riveted blades with a leading edge shape about like a baseball bat, but the Rotorhawk name remained unchanged after going to the extruded blades.
 
Thank you for that elucidation Chuck, seems I have flown them then, and my Rotor Hawks are riveted at the back, with I guess an extruded leading edge.

Yes Brent they do pat up quite nicely. A buddy doing it for you makes it real easy, a little wind makes it simpler when solo.
 
Hi Chuck

Have always wondered about the alloy of extruded blades , the airfoil and are they more subject to cracks from fatigue and resonance.

Tony
 
I'm flying rotorhawks, atleast that was what I was told. Its a riveted blade so i figured it was older style hawk blades! CB can you confirm this? my LE doesn't look like a bat to me! :lol:



Fleck, Vortec and Rotorhawk are all the same if I’m not mistaken.

Extruded 8H12 blades.

Originally, Rotorhawks were riveted blades with a leading edge shape about like a baseball bat, but the Rotorhawk name remained unchanged after going to the extruded blades.
 

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The riveted Rotorhawk blades with baseball bat leading edge came in two flavors; (1) with solid leading edge spar extrusion and (2) with hollow leading edge extrusion.

The solid leading edge extrusion, using a body grinder with 00 grit discs, could be reshaped into something resembling a Clark Y and would then fly very nicely.

I’m referring to the time period when Frank Haller owned Rotorhawk.
 
are mine hawks cb? all the technical details like pitching moments is ok too! :D

The riveted Rotorhawk blades with baseball bat leading edge came in two flavors; (1) with solid leading edge spar extrusion and (2) with hollow leading edge extrusion.

The solid leading edge extrusion, using a body grinder with 00 grit discs, could be reshaped into something resembling a Clark Y and would then fly very nicely.

I’m referring to the time period when Frank Haller owned Rotorhawk.
 
The original Rotorhawks, Red, had an extruded spar with skins riveted on with a jillion rivets. They were perfectly flat on the bottom. There’s nothing wrong with them with respect to safety but they’re draggy.

.Your photo shows something that I have no knowledge of. Perhaps Neil Carnes did not use the ubiquitous extruded Fleck/Vortec blade and came up with one of his own. I’ve never seen one before and know nothing about it.

Bensen blades and SportCopter blades are derived from the 8H12 airfoil but flattened out on the bottom.
 
Brent that's a blade I have not heard or come across. Who makes Fleck blades?

I am now officially in the 'can't remember what I had for breakfast club' as CB had mentioned those very blades on another thread I was trying to follow on blade airfoil sections.

In my defense his earlier mention was perhaps a bit earlier than breakfast.
 
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