Blade mods
You've already seen the lovely carbon blades from Robert Lee. These are my standard blades, weighted as per the recommendation of Graham Stanley from Coventry.
The solder (about 100mm long) is securely taped with clear sticky tape to the leading edge. They steady the rotor noticeably, giving a more stable feel to it and slowing down response to small cyclic commands. I fly these blades with the control exponential removed.
After acquiring another Pic second hand and reasonably priced, I decided to test fly it and then use it to try out things, without taking the original one apart and risking being grounded. One of the things I have tried is Modelsport Hornet fixed pitched blades. I like them! These are hollow glass fibre moulded blades, with a spar roughly at the thickest part of the section and a leading edge weight near the tip. The part number is E059.
To fit: Some fliers mount the blades on top of the head, or cut off the short spigot from the head bottom, or enlarge the blade holes to fit over it. What I do avoids any mods to the stock parts and mounts the blades back under the head as you see above. First fit a washer over the head spigot, just thick enough to hide it, making a flat surface to mount the blade against. I used plastic and made one. Second, put a bit of thin tubing inside the blade hole to shim it out, as the hole is larger than the blade bolts. I used a bit of aluminium and split the side of the tube to adjust its diameter.
The second thing one needs is more headspeed, the blades have far less camber, and I believe pitch, than the Ikarus blades and won't lift otherwise. Typically they need 1500 rpm instead of about 1000rpm. Since the standard 295 motor setup just won't do this, we can either change the gearing to something like 12 teeth (I salvaged one from a cdrom mechanism - shed mentality, can't throw stuff out!) or make the motor go faster. My next experiment was to rewind a 295, and took the stock 65 wind down to 50 turns. This also works, and enables me to use a stock 9 tooth pinion. Using an 8 cell Vanson NiMH pack lifts smoothly, but vertical acceleration is nothing spectacular. Maybe 45 turns would have been better? An alternative is to go to 3 x lithium cells, and this is lively with stock motor/10tooth setup. I land generally after 8-10 minutes as the motor is quite hot. When things have cooled I go fly it again on the same pack. These blades also suit the faster Orion Elite micro modified motor.
How does it fly? A lot different! It feels like a much bigger heli, more like a glow ( /nitro/gas) powered machine. More stable in the hover yet more responsive, I have had to cut the movements down and introduce -ve exponential travel on the cyclic controls. When leaned gently into moving flight, it keeps moving, unlike stock, which tends to resist travelling about. Forward flight is easier, and I've ventured outside, having great fun hurtling the heli around in fast circles and 8s, and runway beatups :o) Also flown in a wind of about 10 mph, it was much harder work, but at least possible. I attribute this kind of flight to the much reduced coning angle of the blades as well as the headspeed.
Turns are also easier while hovering or slow flying, little cyclic correction is required whereas my other Pic needs quite a lean forwards (left turn) or backwards (right turn). I suspect this is because the heli hovers much nearer level, the tail thrust being less (less torque reaction from the main rotor). The level hover makes takeoffs easier too, to the point where they can be done hands off the right stick, using only throttle and a little tweak at the tail rotor.
Is there a downside? Well apart from the above mods required, the blades are spinning faster in an impact situation so are more destructive (and painful). Mine survived a few crashes so far, but I don't expect them to put up with all the treatment my carbons have suffered. Recommended for more advanced flying, and those wanting more nippy performance, especially outdoors.
Here's a Quicktime movie (.mov) showing one of my Pics circling in the hall at Halesowen using these blades. Click here it's about 1Mb.
And another one showing one flitting up and down in the little village institute hall, click here for that one, it is 4Mb, but here is a smaller 1Mb .avi version thanks to Ryan Beall. It will play on the DivX player, or the windows Mediaplayer though I think you will need the DivX codec installed for this one. Free from DivX.com, as is the player.
Update! KYOSHO blades.
At least as good as the Hornet Blades and a LOT tougher; if you can get them, Kyosho M24 Caliber blades. They look like the Hornet blades at first glance, but are not hollow. The plastic is thick and flexible, and the leading edge is thickened to give a forward centre of gravity. The lift and rpm are about the same as the Hornet blades, perhaps a few revs slower but not much (I don't have a tacho but under fluorescent lights the "X" visible on the rotor disc rotates steadily backwards = less than 1500 rpm.) Stability is excellent and flight characteristics in hover and forward flight are rock steady. I've now christened this heli "Mr. Smoothy" and on Sunday 5 January 2006 did my first loop down at the field in calm weather conditions.
The blades need the same gearing, motor or battery mods as before, since the stock setup would be too slow. I'm now running a VL kit brushless motor with 7 turns if I recall correctly, 3 cells and a 10 tooth pinion. Another good property of these blades is there are no mods necessary to mount, they went straight on my 3mm blade bolts. NO balancing or tracking required and they track perfectly.
GET SOME if you can :o)
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