Gyroo!...an autogyro for under £25?

[Edward Po]

Hi All:

 

More novice question

 

I have already completed the bare airframe and reach a point where I need to mount the various servos. My question are as follows:-

 

1) I am using wing type servos for pitch and roll control. is there any special requirement like alignment to the head?

2) What is the push rod thread size of the C30 head?

3) Does a normal push rod usually use in fixed wing aircraft suitable for Autogyro, If not, can anyone recommend?

 

Thank you all in advance!

[Richard Harris]

On 30/08/2022 at 15:22, Edward Po said:

Hi All:

 

More novice question

 

I have already completed the bare airframe and reach a point where I need to mount the various servos. My question are as follows:-

 

1) I am using wing type servos for pitch and roll control. is there any special requirement like alignment to the head?

2) What is the push rod thread size of the C30 head?

3) Does a normal push rod usually use in fixed wing aircraft suitable for Autogyro, If not, can anyone recommend?

 

Thank you all in advance!

 

Edward,

 

To answer your questions,

 

The only special requirement for head servos is to use high torque metal geared type, if you stick to the plan your servo alignment will be fine though be sure to have your servo arms set at 90 degrees to the fuz sides.

Both the C30 and Razor head use M2 threaded ball joints, I just use 2mm diameter wire threaded one end for the ball joint and a push rod connector on the servo arm. I've seen rods made from carbon tube and even wooden dowels with wire bound to them, all work fine, I would use what ever you have as that what the Gyroo is all about.

 

Rich

 

[Christopher Osborn]

Hi. Am having problems with my Gyroo ballooning up vertically after take off. Have built as per plan with an initial hang angle of 18deg. Head was set square to mast as suggested. Blades have 5g weights at tips. Even with an increase in hang angle and a reduction in head angle it still balloons alarmingly on take off and also struggles to make headway into wind as it also balloons up then.

Any advice?

 Thanks, Chris.

[Richard Harris]

Hi Chris,

 

My gut instinct is that you have too much rearward tilt for your particular hang angle as you say you are finding it hard to penetrate into wind, the rotor disc is a very efficient brake if too much is dialled in!

 

A side on photo would help with the model turned on set ready to fly as you have been?

 

Other possible causes that could influence your problem that are worth checking are:

 

Are your head servos strong enough and not being over come by the forces acting on them from the rotor?

 

Is you head plate the correct thickness? a thicker/ stiffer plate will almost certainly push the nose up

 

Is your horizontal stabilizer parallel to the tail  boom?

 

Is your horizontal stabilizer warped? I've come across this one many times.

 

Are your blade shims the correct thickness and in the right location? (if they are thinner this would increase blade lift)

 

Are your blades the correct length?

 

Rich

 

 

 

 

 

 

 

 

 

 

 

 

 

[Thomas W Shelley]

Almost finished my gyroo, but will wait for a nice calm day before venturing out. 

 

Staring at it in the shed, I started to wonder about building another one double size. I would obviously need to think about sufficient strength in places (probably a carbon mast and boom, spruce on the blades trailing edge too for stiffness?, And would need to make my own head a bit like the panther). 

 

Seeing the double size panther on Rich's YouTube channel, it looks like the extra size could make a graceful floater but I'd be prepared for failure anyway 😂

[Thomas W Shelley]

I wanted to anyway ask about the double size panther (couldn't find it mentioned on the panther thread). Were there any notable changes as part of the enlargement? 

Edited September 5, 2022 by Thomas W Shelley

[Richard Harris]

2 hours ago, Thomas W Shelley said:

Almost finished my gyroo, but will wait for a nice calm day before venturing out. 

 

Staring at it in the shed, I started to wonder about building another one double size. I would obviously need to think about sufficient strength in places (probably a carbon mast and boom, spruce on the blades trailing edge too for stiffness?, And would need to make my own head a bit like the panther). 

 

Seeing the double size panther on Rich's YouTube channel, it looks like the extra size could make a graceful floater but I'd be prepared for failure anyway 😂

Good to hear its completed Thomas, let us know how it goes ?

I think a twice sized version would fly really well and not break the bank and could be broken down into modest sized pieces, my Atom Bomber is a large version of the Atom and flies well.

The big Panther has a split fuselage which joins just behind the mast, the front portion is built in the same way as its smaller brother but the rear is a built up light weight structure. 

It flies extremely well but as with most larger models is impractical as a weekend hack.

 

On another note I have had a couple of photos sent me over the weekend of a completed Gyroo.

 

 

Rich

 

 

[Christopher Osborn]

Hi Rich,

Photo shows head angle relative to mast with Gyroo and camera horizontal.

Head servo’s are Corona 239MG’s as recommended.

Plate is 1mm from Coolwind.

Stab is parallel to beam and not warped.

Blades are as per plan although I have not fitted the shims as I thought they mainly aided spin up and that is not an issue.

Have increased hang angle from an initial 19deg to about 21 in an attempt to rectify problem!

Regards,

Chris.

[Thomas W Shelley]

I'm relatively new to all this, but without shims wouldn't that definitely create a lot more lift as they aren't angled down as normal? - am i barking up the wrong tree? It is interesting that the blades still spin up easily without them. 

 

Thanks for the info on the panther Rich - I will have a think and see what i can come up with. Will video the conventional gyroo maiden - for better or worse 🙂

 

Cheers, Tom 

[Richard Harris]

Chris,

 

Thanks for the info, its always best to check these things and it all looks good. It sounds like you have made an excellent set of blades, by adding the recommended shim you will loose a little lift (as Tom suggests), in turn this should sort out the pitching up, assist penetration and give a quicker spin up time.

An autogyro will climb naturally as you apply more power (mine will almost loop from horizontal at full bore with no pitch applied), so use your throttle to control your height into wind, once you get the knack you will be hooked.

 

Let us know how it goes? 

 

Rich

[Christopher Osborn]

Thanks Tom and Rich,

Clearly I still have much to learn!

Will introduce the shims and see how we go.

Will let you know!

Regards,

Chris.

 

[Christopher Osborn]

Gyroo update!

Have shortened the blades by moving the location hole 10mm outboard and added the 0.4 shims.

Decided to hand launch and although it still climbed quite alarmingly it was easier to bring under control.

Once airborne flies great.

 I think a hand launch is the way I need to go with this particular model.

 Thanks for the help,

Chris.

[Richard Harris]

Thanks for the update Chris, good to hear you have got it sorted 😎

 

Rich

Edited September 12, 2022 by Richard Harris

[Thomas W Shelley]

Nice job Chris, looks brilliant

[Richard Harris]

We had a guy turn up and maiden his Gyroo at our September get together, I managed to get a few photos of Graham's fine example.

 

Interestingly he has used Astik manufactured blades that are a SG6042 aerofoil, they are require a little more negative incidence and have a higher speed but performed fine.

 

He has also added a dummy radial to hide the motor and has add what look like wooden guides to run the rudder cable through.

[Edward Po]

Hi all:

 

I have completed the basic airframe and now need to fabricate the rotor blades which I have completely no experience. Advise or direction to suitable article or YouTube clip for the following questions will be deeply appreciated

 

1) How to balance Autogyro blade?

2) How to determine or locate the individual blade mounting hole?

3) For set up, what is the angle of the blade mounting plate in relation with the head mast?

4) Is there a need to carry out CG adjustment / check. If yes, there is the CG point?

 

Thanks

 

 

Edited September 28, 2022 by Edward Po

[john davidson 1]

Full description in the May mag

[Richard Harris]

Hi Edward,

 

Nice work on your Gyroo, as John has said all of your questions are answered in the Gyroo write up, balancing blades is covered  extensively  as it is very important.

Off the top of my head I think the CG position is located 50mm in front of the mast measured from the face as it intersects into the fuselage, this point has a tolerance of +-15mm.

Blade mounting hole is measured 1mm back from the cordwise CG position and the set angle for the head is 90 degrees to the mast (this is the starting point before trimming).

 

Rich

 

[ALAN GREEN]

Hi Guys, Just how critical is blade weight ?   I purchased what was classed as Medium density balsa on-line, from one of the main suppliers.  After I made them and covered them with Profilm each of the finished blades weighed 48g.   I noted from Rich's write up they should be 50-65g.  I have raised this topic as I am not having a lot of success flying it.

The model will take off fine and does not tend to roll left, or right, climbs away fine, at a  reasonable air speed.  However as soon as try and make a smooth turn the blades appear to cause a stall resulting in the model dropping out of the sky before I have time to react.

On the first flight the blade were set 90 deg to the mast,  recommended as the starting point.  The C of G was set 50mm from the mast entry point.

I used coolwinds plates and shims, so this should not be an issue. I was expecting to make some trimming adjustments. But have not managed to reach that stage.

 Using 6.5kg metal gear servos, 2mm rods.

On the second fight I had increased the hang angle by few degrees, however this has not helped.  Making some blade of a higher density balsa appears to be my only option. 

Alan

[Christopher Osborn]

Hi Alan,

Have just weighed my completed blades. Complete with covering, the grp reinforcement plates and a 5g tip weight they are only 44g each. I have increased the negative shim from 0,4 to 0,8 and would certainly recommend the 5g tip weights but apart from that they perform great.

Regards,

Chris.

[Richard Harris]

Alan,

 

Sorry for the delayed reply.

First off your blades should be fine at 48g, a sure sign of blades that are too light is over sensitivity in roll. If you want to add small tip weights to make up the difference it won't hurt, just make sure they are located infront of the cord wise CG and re balance.

You say your Gyroo is taking off and climbing away nicely so your set up sounds pretty good. As it is impossible for an autogyro to stall I'm guessing that it's coming to a standstill in the air and rolling or doing a yawing pirouette?

Without seeing it my guess is that you maybe pulling back on the rotors too much, that big rotor disc is an efficient brake! 

It could also be that too much roll is being used to initiate  a turn, try a larger circuit until your comfortable with it (you can easily bank an autogyro over too much).

Let me know if this helps at all?

 

Rich

 

 

 

[ALAN GREEN]

Thanks Rich for for the info.

I think you may be right in saying may be I pulling back on the rotors. I think I will try and level out a little, prior to making a turn after take off.

Also try and reduce power as the climb out is about 45 deg.

 

Cheers Alan

[Stephen Jones]

Hi,

I have just done a build video for this Autogyro using the pictures I took during the build.

 

 

Steve.

[Richard Harris]

Nicely edited video Stephen, thanks for sharing 🙂

[Stephen Jones]

Thanks Richard,

I guess I could of done things a bit better and earlier.🤔

 

Steve.