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Alsema Sagitta 1:4 scale

Let us all watch your new project progress.
gait
Posts: 3
Joined: 10 Nov 2019, 11:27
Location: elburg

Re: Alsema Sagitta 1:4 scale

Post by gait »

Brian ,

Thx for your info. I’m using devwing to set-up the wing. I’ll have a look into the design.

Br,

Gerhard
B Sharp

Re: Alsema Sagitta 1:4 scale

Post by B Sharp »

It’s been a little while since I last posted as my attention has been focused elsewhere. However I have now started on the paintwork – not my favourite task. The fuselage is sprayed in a white and red scheme which appears fairly simple. When I had the white undercoat in place it shows up all the imperfections in the structure. There then followed a period of re-applying filler to certain areas and sanding once again. This was followed with more primer. Once the rattle-can Appliance Gloss White gloss coat was applied all the lumps and bumps became even more apparent. I came to the conclusion that most of this was down to the fuselage structure and there was only so much corrective filler that I was prepared to apply as it was all adding weight. I have also now added the red colouring to the undersides and the fin flash. All in all, I am not happy with the finish but it will just have to suffice – it will look Ok when 50ft away. :?
You will also see from the photos that I have added the rudder and am presently in the process of mounting the servo and control runs. :)
Brian. :? :? :?
Attachments
The painted fuselage.
The painted fuselage.
The completed fin and rudder.
The completed fin and rudder.
Jolly Roger
Posts: 573
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Alsema Sagitta 1:4 scale

Post by Jolly Roger »

Finish looks good to me Brian. The full size all have bumps, dings and waves, so you’ve just built in extra authenticity. :D
B Sharp

Re: Alsema Sagitta 1:4 scale

Post by B Sharp »

That might be so Roj, but I am still not best pleased with the finished article.
Brian. :?
User avatar
Cliff Evans
Posts: 1032
Joined: 29 Dec 2019, 15:13
Location: Bristol
Contact:

Re: Alsema Sagitta 1:4 scale

Post by Cliff Evans »

B Sharp wrote: 29 Jun 2022, 10:20 That might be so Roj, but I am still not best pleased with the finished article.
Brian. :?
Don't be such an old fusspot!
https://lasercutsailplanes.co.uk
https://patteaklegliders.co.uk
B Sharp

Re: Alsema Sagitta 1:4 scale

Post by B Sharp »

It's the "Old Fusspot" here!

I have not been idle since my last post. The airframe is now all painted. The servos and pushrods are installed and working in the correct directions. Joiners and connectors are installed and functioning. And the mono-wheel has been installed. The LiFe battery has been installed as well as a voltage regulator.

Today I carried out the first full assembly of the model and it all seemed to fit together without any additional fettling. :)
I worked out the ideal CofG position on my favourite CG calculator using a static margin of 15% as a starting point which gave a CofG position 120mm back from the wing leading edge. I also calculated a position with a static margin of 12.5% which moved the CofG back a further 5mm. As a matter of interest I carried out a calculation based on the indicated position on the published plan and this indicated a static margin of 25% which would indicate a very nose-heavy trim. :o

Brian :) :) :)
Attachments
The Sagitta on the balancing jig.
The Sagitta on the balancing jig.
Jolly Roger
Posts: 573
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Alsema Sagitta 1:4 scale

Post by Jolly Roger »

It looks beautiful, Brian. Great job! Hope you bring it down to Leek and Moorland in a few weeks.
Rog
B Sharp

Re: Alsema Sagitta 1:4 scale

Post by B Sharp »

Thanks Rog, and yes I hope it will be in the car.

It's yet another post by the "Old Fusspot"!

The model is now fully balanced and has gone through all the control checks and settings this morning. As it was a nice morning I took the Sagitta outside for it’s official "I’m now complete" photos which you will find below.
I am now waiting for a suitable 10 to 15mph from the southwest or the east so I can lob it of a hill for the first time. I will keep you posted as to the results.

Brian. :)
Attachments
The official "it's finished" photos.
The official "it's finished" photos.
057.jpg
059.jpg
061.jpg
060.jpg
User avatar
Antonia
Posts: 139
Joined: 17 Mar 2015, 22:30
Location: Oxfordshire

Re: Alsema Sagitta 1:4 scale

Post by Antonia »

Looking really good Brian, hope the maiden comes soon for you :)
B Sharp

Re: Alsema Sagitta 1:4 scale

Post by B Sharp »

She Flies!!!
Well, that was Ok!
Weather conditions were forecast to be near perfect for today so the Sagitta batteries were fully charged. Mid-day saw me atop my SW slope with a 10 to 12mph breeze blowing direct onto the slope. I had added a bit of up-trim to the elevators as a precaution for this maiden flight but in the event that proved to be a mistake. I spent the first couple of minutes trying to re-trim to avoid the model stalling. :o
Once I got the Sagitta flying straight and level it proved quite pleasant to fly. After landing I increased the aileron differential a little and decreased the elevator sensitivity and this seemed to do the trick as the second flight was very pleasant.
By the third flight the wind had increased to 18 to 20mph and I discovered that loops, rolls, stall turns and Cuban eights were possible as well as taking a few shots with my camera (see below). I hooked a nice big thermal which took the Sagitta up to 380m which gave me more than enough height to cross-country the half mile back to near my parking spot.
Happy Days! Brian. :D :D :D :D :D
Attachments
Ready for the maiden.
Ready for the maiden.
Proof of flight.
Proof of flight.
063.jpg
064.jpg
Not easy to take this shot whilst flying!
Not easy to take this shot whilst flying!
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