Fire Fly 2 autogyro build

[moorer]

Well done David,a fascinating build thread and well flown.I must admit to being rather interested in building one of these beasts,it is certainly different!

[Concorde Speedbird]

That landing was very impressive, nice model! Well done!

I'm interested to know how the blades spin up to such a speed. When it is flying, with the forward motion through the air, the blades spin due to the incidence etc I assume. But when he was initially holding it they spun up to a very high speed which I was very impressed by! Is it just the wind (since he was holding it into wind) and the fact that he is holding it so far tipped back? Impressive machine! (But I do like my fixed wings!)

CS (intrigued dept)

[David Ashby - Moderator]

Thanks folks, that's very kind of you. I'm going to add a pilot now and perhaps some u/c leg fairings before the next outing.

CSB - yes it's the positive incidence of the blade head - yes too, that was the wind helping the blades get up to speed.

[Cali]

Well done David looks great! and she flys a treat Love the colour scheme!

Now you have the bug you will have no choice but to come to Winterton for the 2013 UK Gyro Meet.

Dates: 19th 20th & 21st July

Cali

[David Ashby - Moderator]

Thanks Cali. That's certainly one for the calendar - I was hoping a few more gyronauts might make Greenacres in June too

It's calm today down here so I'm going to experiment ROGs with the Auto-G before I risk the Fire Fly.

[Cali]

David I would have loved to attended Greenacres, unfortunately I will be back in the UAE the week before, thats the disadvantage of this job, its great working 28/28 but you tend to find that all the good events take place just when youve gone back to work or the weekend just before you return home

Im pretty sure Rich and some of the rest of the gang will be attending.

Good luck with the ROG's Im sure you wont have too much of a problem

Cali

[Grasshopper]

Yes, David do take care with your ROG tests - see below!

I arrived at the field tday to find the forecast 15 mph wind was - zero. Sadly I let the dozen folk who were there persuade me to do some ROG tests. After a couple of attempts I made it for a brief and damaging flight.

The left and right bank controls seemed to be hyper sensitive and I ended up in a heap back on the strip. No blades broken but prop snapped and some easily repairable tailplane damage. I was upset and annoyed at havng been led into this by a bunch of folk some of who had never even heard of an autogiro!

Later the wind did pick up and we did some autorotation tests which went very well. If only I had waited for that breeze.

On returning home the really nasty damage emerged when I found that the mast was cracked right at the base. I will drill out the stub and try to line up another mast no doubt with a good spot of epoxy.

Peter

[David Ashby - Moderator]

Awe Pete, that's a shame, so long as it's fixable of course and a blessing you won't have to make some more blades perhaps too?

Actually I didn't ROG in the end. The wind was 3mph tops and so discretion was the better part and I hand launched after a good run to get the blades spinning up. I think my first ROG attempts will be better in a breeze so I'll wait for another day. The Auto-G had plenty of interest though with many saying they'd like to dip a toe.

[Tom Wright 2]

Peter.

How disappointing  ...should have listened to the Gyro Heads . Are you sure the control throws are set up as Rich recommends ? David's excellent video demonstrates the launch technique very well ,but there was some wind to help with pre rotation.

Hope you get it fixed very soon ready for another try .

Tom.

Edited By Tom Wright 2 on 18/11/2012 17:22:58

[Richard Harris]

Peter,

Unfortunatly these things happen, I would like to say my maiden went to plan but like you I had a bump. My tail twisted round as it left the ground and I did manage to get it down but a little hard and it tipped over, knocked the fin off and motor. Nearly all repaired now , that CG tube from Giantshark is rubbish stuff! It's the seond time that this suff has cracked on me!

I did take a few snaps before I ventured up to the field.

David,

Zero wind conditions are the best for the first ROG, the prop wash helps spin up the rotors.

Rich

[Tom Wright 2]

Nice all metal interpretation of the HK head Rich .

Tom.

[Grasshopper]

Thanks chaps, recovered now a little after a couple of G&T's and a good meal.

Looking back this was a farce. There was the gentlest of breezes across the strip and I was persuaded to take off into it and just welly it across and pull back. It did fly but it was all too sudden: forward motion, the blades suddenly whirring, and pulling to one side, correction too much, then the other way, full throttle - get the picture. It was an accident waiting to happen and it did!

As to throws, I had right/left 17 degrees or so with 60% rates so about 10 degrees each way and also 60% expo. I don't have the lighest of hands on the sticks but I thought that with this expo it would be OK. Should I go for less throws next time?

I will drill out the broken mast stub and take it from there. I will not be beaten as always but will go to the local 'old airport' on a nice breezy day for some hand launch tests before I go back to the home strip.

Peter

Edited By Grasshopper on 18/11/2012 18:15:29

Edited By Grasshopper on 18/11/2012 18:15:51

[Erfolg]

Brilliant Richard.

[simon burch]

Peter,

Be careful with the big expo settings, they can lull you into a false sense of security. Cut the rates down a bit, and drop the expo down to 30/35%, you will not need anymore than that. With big expo settings, things seems smooth and then your controls will bite.

Don't go straight for the ROG's, you will break you model uneccessarily. Best way to get the idea of an ROG is to do a touch and go down the patch when you are flying. Once you get a feel for the required head speed and technique, you will get her to take off in any conditions.

Regards,

Simon

Edited By simon burch on 18/11/2012 19:48:00

[Richard Elliot]

David

Pleased you've had great success......methinks you aill now be well bug-bitten!!. Hopefully I will be attending Greenacres again this year and I'm sure there will be even more autogyros. We may even qualify for a slot!!

Peter

Keep trying because the success when it comes will be so worth it

Rich

Love what you've done with your latest Firefly, and that wooden prop is just the icing on the cake!!.....wish I had a fraction of your imagination.

Cheers

Rich

[Richard Harris]

Rich,

I had no choice the wooden prop is all I had! I have been repairing things and the motor shaft was bent slightly. So in my wisdom I tried to straighten it...yes it broke!

Luckily Giant Shark have spare shafts in stock so have oredered a few spare

Rich

[Grasshopper]

Just finished some industrial dentistry, removing the broken stub after yesterdays broken mast disaster. Sadly in spite of my best efforts I have ended up with a greatly oversized hole.

How best to glue the new mast - tons of epoxy seems the only hole-filler up to the job?

Peter

[Richard Harris]

Peter,

Sorry to hear about the mast, that's the problem with spruce I guess. Good luck with the balsa surgery I am sure the epoxy will do the trick.

Rich

[Grasshopper]

I just received a short video of my Sundays disaster flight - and apart from the stupid launch it seems that if I had been better at the sticks then she would have flown. In fact this short bit of video has told me a lot.

After the ludicrous 'takeoff' into a breeze of only a few kph and the drift to the right I clearly could have flown away as pre-take off you can hear the rotor - but I banged on left and held it on as the FF did its spiral of death. Probably excessive throws and as Simon has said too much expo.

http://youtu.be/jUXRAzUeA3M

 

New mast now made and installed and I will be ready to try some hand launches at the end of the week.

 

Thanks for all the condolances and hints by the way all very comforting and useful.

Peter

Edited By Chris Bott - Moderator on 25/11/2012 12:45:44

[David Ashby - Moderator]

Darn, you nearly had it there Pete, I think you'll be fine at the next attempt

[Grasshopper]

Here's hoping!

Out of interest, what were your throw angles, left and right for your maiden?

Peter

[Richard Harris]

Peter,

Looking at your video as it lifted off it rolled to the right? this is what I would expect to see with not quite enough rotor speed with a clockwise rotating rotor. Once the blades were up to speed it rolled to the left , eventually rolling over to the left. To me this indicates that more right trim is needed for a straight flight path.

I beleive it just needs some trim adjustments, you can never have too much throw to start out, you can then add or remove expo to suit your flying style. It was a good take off if you'd of hand launched that it would have gone in before you could get your launching hand back on the sticks.

I just dont recommend hand launches especially if you are mode 1 and right handed, I have some good footage of myself launching a gyro and crashing it as I could not get my hand back on the stick quick enough to correct. But that is just me, I like to give myself the best chance possible with full control frm the start.

Rich

[Grasshopper]

Rich, thanks for the detailed analysis which is extremely useful. Yes, it rolled to the right on take off and then I remember correcting left, probably savagely and then as it headed for the dozen of us I probaby froze.

As you may have read the 'take off' was a farce as I was presuaded by a dozen French men who had never seen an autogiro before - to give it a good wellie when I would rather have waited for a breezy day and taken off into wind with good blade speed.

My plan originally was to have a launcher - someone who has helped many times in the past and ex-hiloco person - to get the blades up to speed in a breeze and then when he could feel their pull, I would fire up the motor and hopefully it would 'float away' rather like Davids did. Barring that then if there was a breeze down the axis of the strip I planned to use the length of the strip to get the blades up to speed and perhaps do some hops to get the feel for the trim.

In the end neither of these happened and the take off run was only a few metres long with the result that I left the ground - just, and then quickly lost control probably for the reasons you suggest.

New mast made and fitted so I will be ready for another go this weekend. I plan to go to a discused airfield nearby (ex WW2, ME109s flew out of it!) where I can do some taxiing and perhaps some hops - and then who knows I may fly. This way I am away from the ever persuasive crowd who go to my local club.

Incidently, you mentioned Mode 1: in fact I fly mode 2 but the rest of the members (all French) fly mode 1 and think I am very odd.

Report to follow.

Peter

Edited By Grasshopper on 20/11/2012 15:51:51

Edited By Grasshopper on 20/11/2012 15:52:36

[David Ashby - Moderator]

Pete - I'll have a measure when I get home later and let you know.

[simon burch]

Peter, if that had flown straight for another 10 seconds, I think you would have cracked it. Once you get a quick stir on the sticks, you get a feel for whats going on and off you go.

Looking at that video (in my personal opinion), that is exactly what I would expect to see if you have too much expo. Things feel really soft and unresponsive, so you give it some on the sticks and bang, you suddenly have almost full throw. I see too many models set up like this, and it makes them awful to fly, very disconnected. Expo should compliment a good set up, not compensate for too much throw.

I will measure mine tonight as well, so you can have a couple of examples to work from. I would set up some dual rates and cut both the throws and the expo right down. Too much throw is just as dangerous with an unfamiliar model. Much easier to get into the air and think it's slightly unresponsive and then switch to higher rates than have a fight on your hands.

As Rich said, the dive to the right was caused by a lack of head speed. I still think hand launching is an easier approach if like me you have no other autogyro to compare with until you get used to what head speed is required. Just look at how easy David's flew away from his hand.

At the end of the day, that was an autogyro flight. It took off, flew and landed (sort of). Well done, it only gets better from there !!

 

Cheers,

Simon

 

ps. it did look like you corrected the wrong way just before it went in, but that might have been in a panic?? Everything is definitely moving the right way ??

Edited By simon burch on 20/11/2012 16:43:59