Flamingo 3.5metre by Chris Williams - scratch build

[Peter Garsden]

Just making some radiator insulation bags. Put it on the scales at. 7lbs 3ozs which is much less than recommended by Chris at 8lbs. It was tricky to land it properly on the scales but if correct wing loading is 14.37 oz per sq ft instead of 16. I am not confident that the weigh was accurate but I did repeat it several times. If there is enough wind I will attempt a maiden tomorrow.

[Peter Garsden]

Chris recommends filling the gap underneath the aileron join which is quite wide as the aileron is top hinged with a piece of mylar held in place with some double sided tape, so I obliged. The result, as I can testify from today's successful launch is a fast sleek aerodynamic plane.

[Peter Garsden]

I spent a while making some huge bags for the wings and fuselage out of radiator insulation and Duck Tape - very helpful to stop hangar rash indeed so

 

[Ron Gray]

So how did it fly Peter?

[Peter Garsden]

Amazingly well Ron. Fast and very impressive. A doddle to land. Keith took some video so I am going to do a separate post. Unfortunately I could only fly once because, I think, one of the Corona Wing Servos packed up. I am going to investigate later.

[Ron Gray]

Looking forward to seeing the vid. Shame about the servo, I’ve been pleased with the Coronas I’ve had, maybe yours got a virus ? ?

[GrumpyGnome]

Looking great. Hope you have many happy years with it.

GG

[Peter Garsden]

Finally got round to editing the video of the maiden - so what happened? Well I went up to Edge Top near Flash Bar Stores in Flash Derbyshire which is a Leek and Moorland Model Glider Club site on Tuesday 9th March. The wind was light and blowing about 8 to 18 mph - ideal conditions for a maiden. I knew this plane would fly in almost any wind but even still Keith did the honours by launching and videoing

 

It flew right out of his hands. I had balanced it accurately on my Vanessa cradle jig so I was confident. It needed just a touch of up elevator and a bit of right rudder. Movements recommended by Chris - Ailerons 20mm up and down, Elevator 25mm up 15mm down, Rudder 40mm each way. Crow Brakes - spoiler plus 20mm up aileron. I was unsure how to mix in elevator with it not being used to spoilers so I set the right hand knob on my transmitter for elevator fine tuning. I had mixed in some down when actually spoilers need up elevator to compensate for the nose down reaction you get.

 

The model flies so fast and gracefully. It is a peach. I turns very easily without dropping the nose due to its dihedral and positive incidence I am sure. Also 8 square feet of wing area. As it weighed 7lbs 3oz it had some momentum as the video shows. About 14oz per square foot.

 

The Rudder coupled with the ailerons allowed a good deal of counteracting to the otherwise adverse yaw you would get. So yes it is a keeper and will fly again for sure. Chris told me that Mottley whose model and colour scheme mine is based on, took his A test with his in a 30mph wind. Not surprised as it is remarkably slippery.

 

 

I was all set to fly again when I heard a terrible drumming noise from the starboard wing Corona Servo. Don't know what happened but it is a write off - good job it was only £6.99. I think that the tape on top of the wing was too tight and I over strained it. It meant no down aileron so I didn't fly again - very annoying. I have released the tape, pulled the aileron down, and re-taped it. It is now much looser.

[Ron Gray]

Great video Peter and looks amazing in flight. Congrats on a job well done!

 

Just got to build mine now ?

[David Ashby - Moderator]

We’ll done Peter, that looks terrific, it’s a great feeling when it all comes together. 

[Murat Kece 1]

Well done Peter. Looks and flies fab..

[Peter Garsden]

Thanks chaps - excellent service from RC Life - replacement Corona Servos arrived by return of post. Excellent. Fitted and working again.

[stu knowles]

I haven't been following your build but I have to say that the finished model looks absolutely first class.  A lovely scheme beautifully done.

[Ron Gray]

58 minutes ago, Peter Garsden said:

Thanks chaps - excellent service from RC Life - replacement Corona Servos arrived by return of post. Excellent. Fitted and working again.

Which model was the servo Peter?

[Peter Garsden]

12 hours ago, Ron Gray said:

Which model was the servo Peter?

It was the
CORONA DS-239HV SLIM WING SERVO . Post flight investigation showed that the cogs inside the servo had slipped by being over strained.  Odd because they are rated at. 4.6kg. I am fairly sure that I had dialled in some thermal trim on the ailerons which didn't work and over strained the servo. Also insulation tape along the top of the wing join was too tight and had shrunk I think under iron heat. Still not sure 100%. I am more convinced than not that the problem did not lie with the servo but my linkage so I didn't claim a refund. 

[Ron Gray]

Thanks Peter, I’m just about to put one in my Leprechaun (got 2 so will run them both on the exerciser first to check) hence my question.

[2W]

Hi Peter, I've been following your build, and am  delighted to see you have completed a successful maiden flight. I've nearly completed the fuselage structure of mine before starting on the filling and sheeting.

I notice from an earlier post that you added some lead to the nose before covering it with filler. How much (weight) did you add, and did you have to add any more weight to the nose to balance the glider before flying it?

 

Best wishes,

 

William

[Peter Garsden]

2 hours ago, 2W said:

Hi Peter, I've been following your build, and am  delighted to see you have completed a successful maiden flight. I've nearly completed the fuselage structure of mine before starting on the filling and sheeting.

I notice from an earlier post that you added some lead to the nose before covering it with filler. How much (weight) did you add, and did you have to add any more weight to the nose to balance the glider before flying it?

 

Best wishes,

 

William

Good question William. Yes I did add lead but not enough. If you scan back I think I posted a picture. The nose is divided into 4 quadrants. I filled one quadrant with 2 pieces of lead. I should have filled 2 quadrants ie 4 pieces maybe more.  . I had to add about 60 grams of extra lead to make it balance. I was very conscious of adding too much which would have been buried in the nose and impossible to remove. 

 

 

[Peter Garsden]

I flew again last Friday because the wind was between 8 and 16mph according to the forecast. This plane is amazing. The glide angle is so shallow that although it weighs over 7lbs it stays aloft in any wind even when my light weight model would not stay up yet it reputedly flies in a 30mph wind! This is the video I cobbled together

 

 

I wanted to fiddle around with the C of G which is remarkably sensitive when you consider the weights involved. I had used a wood screw to attach some lead squares to F1 on top of the battery. I removed 2, and added 1 back which was perfect. In my first flight it wanted to dive a little too much and needed compensating elevator. My second flight it was a little too nose light. But the third flight was perfect. I could fly this plane all day. Success and a keeper!

Edited March 22, 2021 by Peter Garsden

[Murat Kece 1]

Well done Peter.. The bird looks the piece and  flies fabulously.. I hope I can built one in the future. Enjoy..?

[conrad taggart]

Brilliant video and glider - love the bit where the picture looks like an illustration (really let's you appreciate the lines of the model).    Even the music added something to the video 

[Ron Gray]

Really good again Peter, I’m actually thinking about sticking a motor in the nose for my flat field flying.

[Peter Garsden]

Good idea Ron. There is a picture of a chap who did just that in one of Simon Cocker's columns recently. By the way does anyone know if Simon has stopped his articles as this month Chris W was announced as the new soaring column? 

[GrumpyGnome]

@Peter GarsdenSimon C is concentrating on his other hobby - motor cycles.  Chris W is back! Positive change for me as I prefer CW content and writing style.

 

GG

[Peter Garsden]

Thanks guys. I decided to go flying again yesterday as the wind was a bit stronger at 15mph but the sun was out and the weather perfect. This time I was on my own. Holding down a fuselage and a transmitter for a launch was a bit of a struggle, but I managed it twice without a problem. The issue is that it needs 2 hands to stop it taking off but I need 3 hands - one for the transmitter. There is never a 3rd hand when you need it.

 

I had worked out how to programme my 14SG transmitter properly after buying the alternative manual - god send, I wish I had bought it earlier. It needs less down elevator than up - 15mm/25mm and I had never been able to work out how to do this for several years, until now. I also wanted to try out more up elevator. It needs quite a lot for landing. There is not much space at the Gate to drop her in between the wall and the front of the slope but the spoilers make it easy. 

 

So....3rd launch....I let the glider go with full spoiler on. It landed then the wind cart wheeled it onto its front. It was not a heavy impact but it cracked the canopy base, and split the nose. Damn, I so wanted to fly again. Anyway back to base.

 

 

The crack easily repaired with epoxy and clamped

 

 

This photograph is not to show off Ken's footwear, but to illustrate the lack of fibreglass cloth where the split occurred. I did debate how many layers of cloth to apply and only went for one, whereas 2 or 3 layers of 150 to 200 gram is better. You can see that it does not wrap around F1 which is a weak point as here the ply sides are under tension. All that is holding it because of the open cockpit structure is glue. I am going to take out the detritus and wrap around some Kevlar and fibreglass cloth for extra strength. You can see that there are quite a few lumps of lead, so if the C of G is affected, I can just remove some lead.

 

I am only posting this to suggest to those who are going to build this that more layers of cloth would be a good idea. The problem is that cloth does not do corners very well unless bagged, and that is not possible here, obviously.

Edited March 23, 2021 by Peter Garsden