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Richard Harris

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Richard Harris last won the day on August 4 2021

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  1. Andy, Essentially a rotor blade is a wing, if your mounting point is forward of the cordwise CG it can make it pitch sensitive as with a tail heavy fixed wing. This can cause tracking issues with the blades as can differing length way CG positions, this can also create vibrations throughout the head and control system. Without looking at the plan I am pretty sure I would have set the mounting hole back from the CG to compensate for covering etc, its something I've done for many years. To bring the CG back in line you could always add weight forward of the mounting hole centre (tape may work) around the cordwise CG position? Rich
  2. Steve, You only need half the amount of throw using 2 blades compared to 3 and and a few degrees more rearward tilt. Rich
  3. Great work Steve, looking forward to some flight footage. Rich
  4. Max, The cone angle of the rotor disc will add a roll element in the direction of the advancing blade side, in our case this is an anti clockwise rotation so left trim is needed to compensate. As this cone angle increases so does the applied rotor offset trim, too much cone can also pitch the nose up or down depending on rotor direction when turning using roll (not yaw). It is impossible to eliminate coning of the rotors the same as a fixed wing will always have dihedral (be it minimal) due to the forces acting on them. Heavier blades are the most obvious way to flatten the cone angle on a rotor disc (generally by adding tip weights forward of the CG), the issue here is that it adds a lot more inertia to the blades, creates a slower spin up and increases loads on the whole head control system. I experimented with heavier blades years ago and a simple tip over can result in extensive repairs. Due to this I generally prefer a model that has a medium weight blade as with the Atom, the down side is that left trim needed and varies from model to model dependent on its mass (or the cone angle). To give yourself a head start turn on your Atom hold it and get the blades up to full RPM into wind, if you then position it above your head holding it lightly you should be able to 'feel' any roll acting on it, simply trim to suit until it feels neutral then go for the hops. Hope this kind of explains things? Rich
  5. Andy, I have my gearbox mounted the opposite way around to you with an extra hole drill in the centre of the two existing holes. If you are going to keep yours mounted the same as it is I would certainly add some form of strap at the front as its likely going to be forced upwards in that orientation. Nice job by the way! Rich
  6. Happy New year Steve and good work. Somewhere there is a thread on one of several small models I built a few years back, I did exactly the same thing in using silicon tubing for the pivot. I also found that using heat shrink tubing for the control 'links' worked well, I added drops of CA to the ends of the carbon rod before shrinking. I did several experiments with blades types and ended up with a balsa LE and depron TE profiled with my sharp lower LE edge type aerofoil. The best material used for the flapping 3 bladed head was PPP cut out of a Jacobs Cream cracker lid, 2 blades I used 0.4mm FG sheet. Even with a modest size autogyro you should easily keep it within the walls of an indoor Gym, my reduced size Fire Fly goes well indoors. I had no luck with the mini Nellie, it was a little too fast for indoors, either that or the walls moved! If you need any more info regarding my small stuff just ask, though if you are like me the enjoyment comes from going it alone.
  7. Not heard of that one and I know to a lot of Panthers that have been built. As long as you have free movement of the servo arms and control rods then it will be fine.
  8. That's the big version I think, its more than strong enough for the Panther
  9. Great job that Steve, looking forward to hearing how it goes? Rich
  10. Andy, Just had a quick search and found this https://www.hyperflight.co.uk/products.asp?code=FG-SHEET-15&name=glass-fibre-sheet-1-5mm
  11. Nice covering job, not a lot left to do now! Not sure if you have seen this, a friend sent me this photo taken from the pages of this months Model Aviation Magazine your side of the pond. I think the mag is kind of like our BMFA news over here, though I could be wrong.
  12. That's coming along nicely codepox, are going with a canopy?
  13. Sort of... I couldnt get it to spin fast enough to start with adding more negative incidence with each attempt. Once it did spin up it was getting into autorotation and a hand launch saw a fast descent. The blade used was a weighted Panther type so it may be a case of lengthening the span to give the extra lift needed.
  14. A single driven blade is more efficient, at the moment the only efficient thing I'm achieving is breaking props! Not wanting to give up easily though
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