Skybug One

[Lindsay Todd]

Time to start building something a little different as a new design, this one has been on and off the drawing board for quite some time. I fancied doing something with a bit of a Sci-fi focus to it or even an underlying story line to it. what i came up with is a sort of utility vehicle / aeroplane; an all terrain aircraft. What ? i here you say - well bear with me and it will hopefully make sense and appeal to a few i hope. I almost think Gerry Anderson could have used this one and i guess in part that was my inspiration.

So here goes first line drawing visual of Skybug One

Yes that is a folding wing and yes there are 6 wheels and yes the fuselage has the aerodynamics of a house brick and yes it has an anhedral wing although the tail may well become a more conventional dihedral V tail once i have done a bit more maths on stability factors. Warned you it was different. Hope to start gluing wood together in the next couple of weeks. Linds

Edited By Lindsay Todd on 31/10/2020 19:09:30

[Dane Crosby]

Aha. Very impressive. Look forward to see it built.

Reminds me of the Gigant.

[Piers Bowlan]

Lindsay, but April 1st is not for another six months! 

 

Edited By Piers Bowlan on 01/11/2020 06:42:56

[Lindsay Todd]

I have done some more work on this design and the plans are now complete, revised the tail to a more conventional V tail and set of cnc parts now cut so construction will start very soon. However one part of the design is yet to be fully resolved and that is the steering. I don't want to loose the 6 wheel layout but this has raised issue on how will it steer during taxiing and take off and landing. i have come up with a flexible wire that applies friction to the inside edges of the front wheels offering a type of brake steering, does anyone have any experience of this or am i down to a bit of experimentation? Linds long shot i know but if you don't ask

[Dwain Dibley.]

I wouldn't have thought it would be a problem unless they are far apart, ie long wheelbase.

I made a four wheel dolly for a 109 and it steered without probs.

D.D.

[Lindsay Todd]

A way over due update, this was not a joke design and now progressing nicelywhen nearing test 

Apologies for the poor quality image, taken with old camera i keep in the workshop but shows Skybug now in quite and advanced state of construction. Its good to have fun sometimes with something totally off the wall. I will up date again when nearing test flights and if all goes ok could be a plan feature?

Linds

[Futura57]

Words fail me 🤔

 

...

 

in the nicest possible way 😂

[Rich Griff]

Gigant...

 

Don't forget the swastika's...

 

Anyone made the special gigant tug made from joining two hienkel bombers ?

Edited August 6, 2023 by Rich Griff

[Shaun Walsh]

Will probably fly better inverted.

The front of the fuselage will produce a lot of drag, cut the motor and it will probably stop dead.

The tailplane on the model doesn't correspond to the drawing.

That's a lot of fuselage area ahead oh the CofG and not a great deal of tail fin/rudder behind it.

Edited August 6, 2023 by Shaun Walsh

[Lindsay Todd]

All valid points Shaun, except the inverted issue, but then if we want something different then we have to challenge the accepted norm. Quite a lot of math's actually sits behind this design and as we all know the truth will out when we put the science into practice. the whole concept here was not about designing an efficient aircraft but something that was fun, in such cases hi drag (Fokker Tri-plane) can be fun and challenging but not the best design from a drag perspective. In fact if you consider many of the WW1 types there is much comparison in surface area, drag and fin and rudder size. This is a compromised design else we would have another pattern ship - very boring to my mind.

 

Thanks for the input, the truth will be evident after initial flights, maybe it will have an incredibly stable inverted flight performance after all - love the challenge!

 

Linds 

[Shaun Walsh]

Will be intrigued to see a video of it flying 🙂

[Lindsay Todd]

Always look for interesting pilots for new projects and came across these two fine chaps at a car boot - perfect

 

done quite a bit of work on the wing now and ready for covering

 

heat shrink fabric to the open structure and glass cloth and acrylic resin everywhere else, hopefully just a few weeks before ready for test flights

 

should be interesting. Linds

Edited August 20, 2023 by Lindsay Todd

[MattyB]

19 hours ago, Lindsay Todd said:

should be interesting. Linds

With that combo of the wing anhedral, short moment arm, relatively small v-tail and large fuselage side area in front of the CG, then “interesting” may be an understatement…

[Geoff S]

I'm full of admiration for your undoubted courage - still, nothing ventured, nothing gained.  'Interesting' might be an understatement but your other designs fly perfectly well so this wouldn't dare to fail 👍

[Richard Harris]

I like that Linds, good luck with the maiden.

 

Rich

Edited August 21, 2023 by Richard Harris

[Lindsay Todd]

I think the camera angle is making the V tail area look worse than it actually is but there is no doubt I am sticking my neck out a bit with this one. I think it will be one of those moments when if it actually rotates on take off then it should be ok, 

Thanks for all the comments. Linds

[Steve Adams]

That's certainly unorthodox! Any particular reason for anhedral as opposed to dihedral on the wings Lindsay?

[Lindsay Todd]

Basically with a high wing deep fuselage there is a high degree of roll stability, this is a good thing but can be too extreme when we push the design envelope and can induce over stability causing other issues such as lack of roll and adverse yaw. Anhedral decreases roll stability or put another way increases roll performance to counteract the induced stability of the high wing deep fuselage section so increases maneuverability. In very simplistic terms but that is the basics.

Plus I just like the look! Linds

[MattyB]

15 hours ago, Lindsay Todd said:

Basically with a high wing deep fuselage there is a high degree of roll stability, this is a good thing but can be too extreme when we push the design envelope and can induce over stability causing other issues such as lack of roll and adverse yaw. Anhedral decreases roll stability or put another way increases roll performance to counteract the induced stability of the high wing deep fuselage section so increases manoeuvrability. In very simplistic terms but that is the basics.

Plus I just like the look! Linds

 

If you like the look then fair enough, but I suspect the anhedral is trying to solve a problem that won't exist... Put side by side with a DH3C for instance, there isn't that much difference in fuselage depth, and that aircraft has some slight positive dihedral. It also has a lot more vertical fin area...

 

 

 

[Lindsay Todd]

Well its not exactly comparing apples with apples is it, something like the Beechcraft Bonnanza

might be more appropriate and proved to be a very efficient design despite a very low profile fin area disguised in its V tail layout so we have to be conscious of that. I bow to your knowledge of low drag coefficient slope soaring but this design is not about efficiency it is a caricature design, it has many compromises, it should be challenging and that's half the fun.

 

[Lindsay Todd]

Since the weather has impacted progress i have been getting the model finished off with heavily weathered paint finish, more of later, but had some fun today making up a little seat and dashboard arrangement from the scraps books

 

Linds

[Futura57]

Definitely a design where I would have first knocked up a Depron reduced size chuck glider before committing. And maybe whacked a small electric motor on.

 

Good Luck

 

It could become the defacto toffee bomber, who knows. No offense intended.

[Simon Chaddock]

I am more concerned by the fuselage blanketing nearly 20% of the prop swept area. In addition such blanketing is likely to upset the prop blade airflow over a bit more of the prop arc. This will effectively make the thrust line even higher above the centre of drag. Where is the battery to be located?

Now if you fit a gyro all these issues would disappear. 😉

 

I note the straight wing Airbus A400 only has slight anhedral whereas on the swept wing Antonov AN124 it is very pronounced. Perhaps the natural stability of a swept wing is more influential on roll stability than the fuselage side area.

 

The flight results will be very interesting.

[Lindsay Todd]

Ever closer to first flight, paint finish now well on the way, still a bit of cutting back to do but going for that well used look.

The prop shown so far is just one hanging around and is only a 9X6 but the eventual is likely to 11-12 inch so that will mitigate a bit of the thrust / drag issues

The battery sits right behind the motor in the cooling duct, actually a nice feature  and gives easy access.

Gyro? how very dare you sir, this will be a white knuckle ride!

 

Linds

[Shaun Walsh]

34 minutes ago, Lindsay Todd said:

Ever closer to first flight, paint finish now well on the way, still a bit of cutting back to do but going for that well used look.

The prop shown so far is just one hanging around and is only a 9X6 but the eventual is likely to 11-12 inch so that will mitigate a bit of the thrust / drag issues

The battery sits right behind the motor in the cooling duct, actually a nice feature  and gives easy access.

Gyro? how very dare you sir, this will be a white knuckle ride!

 

Linds

How about:

Automated

Recovery

Services

England

 

Run by the Trotters of course.

or Father Jack Hackett.

Edited November 5, 2023 by Shaun Walsh