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Gyroo II 'the pusher version'


Richard Harris
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I am a little surprised that you have still gone with an of center motor.

I have found that a central motor mount on my modified Mantis and my own WA 116 design, there is no noticeable difference ?

I could put this down to my modest expert skilled flying capability......(but I very much doubt that.)  or the fact that it does not make a great deal of difference?

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I should start by saying I have never built an autogyro so maybe I shouldn’t comment but presumably the motor offset from the model’s centreline is to counteract yaw as a result of the slipstream effect from the pusher prop on the fin and rudder? Could you not achieve the same fix by introducing a few degrees of motor side thrust rather than offsetting the entire motor?  Just a thought.

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Posted (edited)

Chris,

 

   It is something I've not experimented with much, when I have I needed quite a lot of side thrust to compensate the yaw effect generated and it looked a bit daft if I'm honest.

That said, this was with lower KV motors swinging larger diameter low pitch props with a shorter tail to CG moment arm.

If you do try it let me know how it works out? the beauty of you experienced beta builders are you always throw in excellent ideas. It's no problem for me to change things to the plan at this stage so I am all ears, simpler the better in my eyes.

Piers,

Yes, that how I have always understood it, there are several ways to overcome the propwash effect.

Offsetting the  motor is the easiest way of getting around this as it keeps the thrustline square on through all of the power range (this helps when the rotors are off loaded with reduced airspeed).

You can also add a variable rudder trim mixed with throttle, Micromold tried to get around it by shaping the fin/ rudder into a flat bottomed aerofoil.

Edited by Richard Harris
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Not sure whats going on but I keep getting a pop up box appear, strange.

 

Anyway, I got out again today for my first fly of the year.

The new motor mount is now fitted, had to move the motor up a tad as it was pitching up a bit under power.

There was virtually no wind so I could confidently fly it at close quarters once trimmed.

The flight was a good 8 mins long according to my unedited footage which is encouraging. There was about about 30% left in the battery, that's with me flying it in an autogyro fashion  and not like a pylon racer.

It's pretty much dialled in now so  time for me to sit back and see if the Beta testers models reflect the same excellent flying qualities of mine.

 

Here is today's vid, enjoy.

 

 

 

Rich 

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A few photos I took today of Steve's Gyroo II on its maiden voyage, after a few adjustments it was flying like is was on rails. His model was then set up on a mode 2 transmitter for Rich E to have a go with to which the pair undertook a bit of formation flying with the pair.

Video will follow once I have had chance to look through them.

 

Well done Steve, a stirling job

 

 

 

 

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Looking good Chris,

 

On both of the flying models we have added ballast nose weight. Steve's more so than mine which is probably down to his tail plane holder being made from birch ply rather than lite.

The plan will be altered to take this into consideration with either a marked area or ballast box to add lead.

We have both had to move our motors upwards a tad to which they are pretty much identical, with Steve's he had to get out the scalpel to cut his mast fairing to be able to achieve this. On reflection I would stick with the plan motor mount and mast whilst trimming and setting up, then pretty things up after.

Nice 3d printed blades by the way, I would go for the longer 560mm length as the best replicates what we are using up this end of the world. You will find that the extra lift/drag along with the generous tail plane area will dampen out a high motor thrust line, I will take a photo of mine hanging to give you a good idea when I get chance.

Both flying models are very  predictable, the transition in airspeed as you throttle up takes a little longer with the 8" prop is very smooth which will be perfect for the first time pusheroo. 

Keep us updated of your progress please?

 

Rich

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 Hopefully ,I may not have a balance problem as you will notice that I have modified the top ,front of the fuz just a little trying to get that "Calidus" kind of a profile and I am not in a position to get my hands on light ply. My biggest hold up at the moment is waiting for some props to arrive.

 Chris...

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Chris,

 

           I did notice the arc was different on the top half of your fuselage, best place to have any extra mass I guess.

Regarding the fuselage, I've been half tempted to draw up a full bodied version as I think it would look quite good. It would go against the ethos of the Gyroo so maybe a complete new model would be on the cards for a future project.

 

Rich

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