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Twister a 2 bladed autogyro


Richard Harris
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On 05/06/2021 at 13:57, Mike T said:

Looks superb Rich!  You certainly have an eye for a colour scheme ?

Mike, Thanks! but to be fair it is just a stripe, nice and simple.

 

Blade blanks are pretty much profiled now to my own section, I have made 2 sets up.

The 2 blades are around 9mm at their thickest point, I have added a small spruce TE to toughen them up.

The 3 blades use a thinner section ar around 6mm, they are basically Revolver II blades.

 

Next I will size each set using Pieter Mulder's Excel programme based on the AUW of my new model and how I would like it to perform. Will make a short video as I do so.

 

Rich

 

 

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On 11/06/2021 at 07:29, Ace said:

Looking fantastic - ?

 

Rich, what wood have you used for the blades LE?

Ace,

 

The shorter blades use pine for the LE. Unsure of what the thicker stuff is, I get it from a local diy store. Could possibly be obechi, next time I go I will enquire.

 

Rich

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17 hours ago, Richard Harris said:

The shorter blades use pine for the LE. Unsure of what the thicker stuff is, I get it from a local diy store. Could possibly be obechi, next time I go I will enquire.

Rich

Thanks Rich,

I could see it was a different wood and wondered if there was a reason - lighter, no grain or simply availability, so spruce would be ok on the LE? 

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Ace, Spruce (or maybe Obechi) is more 'ding resistant' than Balsa. Also full size helicopters often have a weighted LE to give the blade a forward c of g (sometimes a brass strip running inside an a Ali alloy extrusion). Don't know if the same applies to an Autogyro.

 

Model looks very stylish Rich, looking forward to the plan. ? 

Edited by Piers Bowlan
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I will be adding a small amount of tip weights to the two blades. 

Have been checking the alignment of my sub fins, rudders and right thrust to give me the least amount of thumb juggling on the maiden. Simple hang power test soon had it stationary tethered from the washing line, this also confirms vertical fin area is adequate.

 

As progress has been zero on my blade blanks I will probably use a proven set for initial hoos 

Looks like our Peterborough fly in next Saturday will be the day. Anyone else going?

 

Rich

 

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The Twister has now had several successful flights but not not as smoothly as I liked.

First time out was a little hairy as it was a bit twitchy in pitch but I did manage a couple of progressive flights to which the conclusion was a more forward CG was needed.

Rather than add church roof I opted to move my rotor spindle further back. This was achieved by making a new mast cranked back.

Yesterday at our meet I had several flights ending up with a quite stable model.

My only issue is that yaw authority is weak so I will redesign the tail feathers.

On my last flight I didnt take my own advice taking it too far away and getting disoriented, an axial roll into inverted followed,rotors stopped and it converted into a lawn/crop dart.

Luckily only the mast snapped on impact.

I will concentrate on the modifications required then get out again.

A few snaps taken of it in flight.

 

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Edited by Richard Harris
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Hi Richard,

Watched your video and the model seems to be showing the same behaviour that my Lidl version did.

I reduced the roll rate to 50% of travel but left the pitch at 100% I also added 40% Expo to both pitch and roll.

My model flies great now RoG are good too. I also programed a slider on my Tx so I can alter the Pitch for different weather conditions.

Might be worth a try if you have not done this already. ?

 

Not that I am a expert in these matters, just my experience with a similar model. 

 

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Yours looks way better than my foamy and I know mine Bounces well too ?

 

Steve.

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On 28/06/2021 at 17:23, Paul De Tourtoulon said:

Well that was a good flight, I have built flow and crashed a few of these devil designed machines, all methanol powered,  average 3 flights = 1 broken blade,,

 

 well done, and yes it does look nice.

They aren't for everyone but if you do happen to still have one in serviceable condition why not bring it along to our annual gyronuts fly- in in 3 weeks?

You will not find a more helpful bunch of folk, always willing to advice, set up and test fly auto's in both transmitter modes.

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  • 11 months later...
On 28/06/2021 at 09:14, Richard Harris said:

This is a video taken by Malcolm of its 3rd flight on Saturday, you can clearly see I am working the stick far more than I should be!

 

 

 

Rich

I've just been meandering around YouTube on the telly, when this video popped up under recommendations and I re-discovered this thread!

 

What progress please, Rich?  I hope negotiations for a mag. plan are well underway! ?

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19 hours ago, Mike T said:

I've just been meandering around YouTube on the telly, when this video popped up under recommendations and I re-discovered this thread!

 

What progress please, Rich?  I hope negotiations for a mag. plan are well underway! ?

Mike,

 

It lies somewhere in my shed and has not been touched since that flight. I need to increase the fin area and rudders, when I get round to it I will try and grab some footage.

 

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Hi Rich,

The Twister is without doubt the best looking autogyro out of all your marvellous creations. A great many seasoned gyronuts and potential gyronuts would be very pleased to see a plan of this in the mag.

Congratulations on another superb design Sir.

Kind Regards 

 

Steve 

 

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On 10/06/2022 at 00:17, Steve Adams said:

Hi Rich,

The Twister is without doubt the best looking autogyro out of all your marvellous creations. A great many seasoned gyronuts and potential gyronuts would be very pleased to see a plan of this in the mag.

Congratulations on another superb design Sir.

Kind Regards 

 

Steve 

 

Steve,

 

Thankyou, I have blown the dust off it and re made the fins after you stirred a bit of interest in it. They are about twice the surface area of the originals, 2/3 of these are  rudder so I am hoping this will sort out the yawing instability encountered on that last flight. 

If the weather is kind I hope to re-test fly it at our annual autogyro Fly-In this coming weekend, fingers crossed.

 

Rich

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I managed to retest the Twister over the weekend with its new modifications and it is now flying really well, one of the local club members of WMFC took a few snaps of it, thanks Mike. I need to tweak my side thrust, once done I will try and capture some flight footage, I'm pleased with this one.

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