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Gyroo!...an autogyro for under £25?


Richard Harris
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This one started out as a bit of fun during one of the lockdowns, I wanted a simple/ robust model that has replaceable parts that can be quickly swapped at the field. As balsa was almost none existent at the time but hardwoods, lite ply were plentiful it was designed using a lot of  these and with todays inflated prices the basic build materials for this model (balsa, ply, hardwood and lite ply) totals under £25, in fact, you can almost make two airframes from this!

 

Moving on 6 months  I asked a few gyronuts if they wanted to join me to beta test the Gyroo! this started a few weeks ago and 3 fine looking examples were ready to test at our annual Autogyro fly-in last weekend with another being built in South Africa. Two of the models had already flown with differing blade lengths and battery options.

The results from the weekend went really well and there was a lot of interest, so much so I think I will try and twist Mr Coziers arm a bit and see if he's interested in it for publication 😉

Coolwind have all the info on head plates and will be able to cut a small part kit for this hopefully (though it doesn't take much to do it by hand). My prototype uses a 4max set up which gives more than enough power (loops are a doddle) and I'm sure George will make a power set up available if it all goes to plan.

I haven't got any build photos as it went together really quickly, so will probably add some as I build another and snap away.

Basically it has a main pod to which the mast/ boom slots into with the tail also being removable, there is a sedate version for first timers and can be adapted as a hot dogger version.

For now a few flying shots and a couple of videos.

 

More to come....

 

Rich

 

 

 

 

 

 

 

 

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With flying shots out of the way the pressure is off so I have been pushing it a little more this morning.

With the extra angle of attack sat on the ground there is no no need to pull the rotors back in the normal way, a quick flick in the right direction and about half throttle will soon get it in the air. In fact, on a couple of occasions I did nothing other than set the throttle, it was ROG without any other input from me. I was going to try and capture some footage of this but my camera is mounted to the top of my transmitter, maybe next time.

It easily does loops on the 4max set up by simply adding full throttle and a touch of rearward tilt, backing off the throttle on the downward arc.

Rolls are achievable too, though they are more of a barrel roll as you will see, full roll and full rudder in the same direction are needed without backing off the throttle at full chat.

It does a funny kind of spin with full rudder set at about 45 degrees, I can almost maintain height with power applied and a little rearward tilt. 

Calm all of the controls down and its a docile as any other trainer type but stronger.

The sky was grey up at the patch this morning but I did grab some footage of the loops etc, as you will see I ended up doing the rudder spin a little to low breaking the fin off. Luckily this just unbolts off and is easily replaced, of course I hadnt got a spare with me!

 

Rich

 

 

 

 

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The thought of going through hundreds of blades learning to fly an Autogyro has always put me off (everyone I have seen experiment with them seems to fall foul of this!), but this does have me tempted for fslow flight in my local park...

 

I am a competent fixed wing aerobatic and glider pilot, how hard are they to fly? It looks like the primary directional control may be rudder, with ailerons just being used to harmonise the turn?

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Steve,

You cant beat simplicity sometimes, thanks for the encouragement.👍

 

Matty,

 

I don,t see you having any issues with an autogyro, they are not hard to fly for a competent fixed winger but do require a different mind set. Most will agree with me that the biggest hurdle is orientation issues and getting them off the ground when you are used to fixed wing ROG's. All easily overcome with a little bit of practice.

The closest thing I can think in likeness to  flying an auto is a WWI biplane which is being flown correctly (not yank and bank) where a balance of rudder and ailerons are used to flatten the turns.

The tighter turns on the video are nothing more than 'control line' turns as you would do with an aerobatic model, just adding power to maintain height and opposite roll to the yaw direction.

To be honest I have not broken many blades over the years unless its a real heavy return to earth and I don't know many who have. The blades on the Gyroo use a 9.5 x 6.5mm spruce leading edge so are robust once made up.

From my experience the most vulnerable part of an autogyro is generally the tail feathers and the mast. 

On this one they are all removable so no reason why a newbie couldn't have a good training session at the patch armed with a few sets of spares.

Never seen those type of aerofoils used on an autogyro before, possibly an option for someone to give them a try?

 

Rich

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Hi Richard,

 

I still have the remnants of my crashed Atom, including a fully intact mast, rotorhead and blades. Is the Gyroo anywhere near that size? It looks bigger.....

Any chance of a simple GA sketch so I can scale it down?

 

Max.

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12 hours ago, Max Z said:

Hi Richard,

 

I still have the remnants of my crashed Atom, including a fully intact mast, rotorhead and blades. Is the Gyroo anywhere near that size? It looks bigger.....

Any chance of a simple GA sketch so I can scale it down?

 

Max.

Hi Max,

 

I think that the Gyroo is bigger though it wouldn't be a problem for me to scale down on SW.

One of the things that we have been testing on it is differing blade lengths, 550, 520, 500 and 470mm  have all worked well on an average AUW of 900g.

I cant remember the length of the Atom Special blades or its AUW but I'm sure it wouldn't be far off the weight of the Gyroo. If its close there is no reason why you couldn't recycle your Atom parts.

I will see if I can dig out the mag that the Atom was published in and have a look at the specs.

 

Rich

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On 02/08/2021 at 18:07, MattyB said:

PS - Has anyone tried Kline-Fogleman aerofoils on an autogyro, maybe the KFm-2 or 3? This (admittedly slightly flimsy) paper seems to indicate they could have promise, and they would certainly be easier to fabricate than "true" cambered aerofoils...

 

An interesting idea Matty, and I think you are the man to try it! 😉

Looking forward to the plan, although I wouldn't want it scaled down for, as far as orientation is concerned, bigger is better 🙂

What motor/prop are you using Richard, by the way?

 

 

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10 hours ago, Piers Bowlan said:

 

Piers,

 

I'm using a 4max PO-2834-1020kv turning an APC 11X5.5"E off a 3s 2200mah Lipo through a 40amp esc.

This  has plenty of power to hand as I can pull loops from the horizontal without too much trouble, it could be propped down a bit to give a more relaxed Gyroo with a longer duration.

It's been tested with several different sized Lipos, 1300mah being the smallest and 2200mah the largest, very little pitch trim changes between them but it was noticeably lighter loaded with the smaller pack.

 

Rich

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10 hours ago, Richard Harris said:

It's been tested with several different sized Lipos, 1300mah being the smallest and 2200mah the largest, very little pitch trim changes between them but it was noticeably lighter loaded with the smaller pack.

 

Interesting stuff. Two questions...

  1. How do you CG an autogyro (is there a rule of thumb based on positioning CG as a % of the disc rotor sweep etc)?
  2. Does weight affect an autogyro in the same way it does a fixed wing (i.e reducing weight increases climb rate and manouvreability, decreased penetration, model gets more affected by the wind etc), or are there other/different effects that are specific to autogyros?
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On 02/08/2021 at 22:48, Richard Harris said:

Never seen those type of aerofoils used on an autogyro before, possibly an option for someone to give them a try?

 

22 hours ago, Piers Bowlan said:

An interesting idea Matty, and I think you are the man to try it! 😉

 

PS - I think I may have made a rod for my own back here....!

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On 05/08/2021 at 10:00, MattyB said:

 

Interesting stuff. Two questions...

  1. How do you CG an autogyro (is there a rule of thumb based on positioning CG as a % of the disc rotor sweep etc)?
  2. Does weight affect an autogyro in the same way it does a fixed wing (i.e reducing weight increases climb rate and manouvreability, decreased penetration, model gets more affected by the wind etc), or are there other/different effects that are specific to autogyros?

Matty,

 

If you can imagine a line running straight through the centre of the rotor spindle downwards, as the rotor is moved back this line moves forwards. This line should never go in front of the horizontal CG, if it does its like having a tail heavy fixed wing in that pitch control becomes sensitive. You can have a great flying autogyro that becomes a pig when the disc is pulled back too far, all because the CG is not quite forwards enough.

The extra weight does effect an autogyro in the same way if the CG is kept in the same position,  I have tested different sized batteries on the Gyroo but they have been positioned in a way to try and keep the CG roughly in the same position. I've sloped one of my models and needed extra ballast to increase the rotor loading so I could get some sort of penetration forwards, worked well into wind but only good for going from side to side. Could never pluck up the courage to try a circuit.

As it happens the Gyroo's CG across 3 test models is within 15mm so I will be able to give an accurate measurement with a good  tolerance to spare for the final drawing.

 

 

On another note, I'm just in the process of trying to simplify the multi thickness plates adopted for the Revolver II that has been used on the Beta models. Hopefully it will be more like the Atoms. will report back if all goes well.

 

Rich

 

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Each of the Beta models have been flying well on the multiple tri plates as used on the Revolver II, this uses a circular anti strike plate with two flex plates. With mine I added a n extra full triangle made from carbon fibre to keep the blades away from the more traditional tail.

To try and keep things a bit cheaper and simpler Malcolm at Coolwind has made me a full triangle anti strike plate from 1.6mm FG and a single triangle from 1mm FG to mount the blades too.

I have just assembled these together so am hoping the weather improves  to test this new combination.

A few photos of the new parts and the original carbon plated assembly.

 

 

Rich

 

 

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Hi, A little bit off topic but recently built the cranefly from Dear old Tom Wrights plans mainly from scrap balsa i had laying around and the only expense i incurred was the delta plate and bearing from coolwinds models. I had messed around trying to get the blades to spin to no avail but eventually succeeded by increasing the negative pitch. So this afternoon off i went with my fixed wing models and my Cranefly and really the conditions were not ideal with wind speed around 9/10 mph but it got to the point where i thought bugger it not got anything to lose so i let the blades spin up to what i thought was faster enough and then hand launched into wind and to my amazement the Cranefly flew. I did not do any trimming at all and just did 5/6 circuits left and right turns and then brought it into wind and brought it in for a perfect landing. Just to make sure it was not beginners luck i had a second flight and apart from being tossed around because the wind was picking up i then brought it in for another decent landing. So today i was a happy chap bringing it home in one piece and now will wait till there is better conditions before i try again. Just thought i would share my first Autogyro flight.

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9 hours ago, bees said:

Hi, A little bit off topic but recently built the cranefly from Dear old Tom Wrights plans mainly from scrap balsa i had laying around and the only expense i incurred was the delta plate and bearing from coolwinds models. I had messed around trying to get the blades to spin to no avail but eventually succeeded by increasing the negative pitch. So this afternoon off i went with my fixed wing models and my Cranefly and really the conditions were not ideal with wind speed around 9/10 mph but it got to the point where i thought bugger it not got anything to lose so i let the blades spin up to what i thought was faster enough and then hand launched into wind and to my amazement the Cranefly flew. I did not do any trimming at all and just did 5/6 circuits left and right turns and then brought it into wind and brought it in for a perfect landing. Just to make sure it was not beginners luck i had a second flight and apart from being tossed around because the wind was picking up i then brought it in for another decent landing. So today i was a happy chap bringing it home in one piece and now will wait till there is better conditions before i try again. Just thought i would share my first Autogyro flight.

Bees,

 

Thank you for sharing, good to hear you have got your autogyro wings. The Crane Fly is a well thought out autogyro that is sure to give you many hours of fun, exactly as Tom intended. 

 

Rich

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25 minutes ago, bees said:

Hi, Still not had chance to fly the Cranefly due to weather, hopefully tomorrow but i have a plan for the Panther from a few years ago and was wondering if the Panther is the next step up. Thank you for any advice.

Bees,

 

Panther was designed as a larger trainer so should be fine if you have got to grips with the Crane Fly.

 

Between flying kites with the kids I managed a couple of circuits with the Gyroo and the 1mm tri plate this afternoon.

I couldnt tell any difference compared to the Revolvers multi plate previously fitted which is encouraging.

I will try and get some footage in the next few days.

 

Rich

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