Category Archives: Scratch-built

Project SBSW (Update 12) Flight tests

Here’s a video* of the Scratch-built skywalker in a couple of flight tests in Brittany R/C field over the weekend.   I had to make a couple of changes in the motor thrust angle as the plane had a tendency to pitch down when the throttle is applied.  It was a tad too windy for a flight test, but I was able to fly the plane in previous tests in a similar condition…  I wont certainly fly in this condition if it were a maiden flight.

I recently bought the real thing, a 1.9m 2014 Skywalker.  I’ll post some build images and the maiden soon.

 * courtesy of the wife =)

Project SBSW (update 11) Take off!

The new wings I’ve been working on for the last couple of weeks was well worth it.


Here it is last night, with the skin on:


And finally, this morning ater a successful flight:




The 1.4kv turnigy aerodrive motor, 10×6 prop and 5000mah battery gives ample thrust.. the plane can fly really fast.

Stall speed is low.. even lower (it seems) than my 1.4m hitec skyscout. No doubt the airfoil (as close to NACA 4412 in case you’re interested) made a huge difference.

However throttling up causes the plane to pitch down negating the lift.. nothing which some up elevator cant fix though. It looks like I need to put in some more down angle to the motor now that the CG is known.

The elevator also needs to be secured more firmly to prevent it from rolling (wagging really) which affects the flight characteristics somewhat specially when banking.

Will post a video soon!

Project SBSW (update 7) installation of fuselage

Did some work on the plane tonight and was able to finish installing the main fuselage section with the wing base on top and added some “strengthening” PVC at the  back and front.


At another angle:


Update: a few hours later..more panels..


I have 4 more days to finish this for the maiden. I reckon I can finish the fuselage tomorrow.. the wing attachments on wed, the electronics and servos on thursday and friday.

Crossing my fingers!

Project SBSW (update 6) motor mount, wing mount and partial fuselage

Today I finished some important parts of the project. The motor is screwed to a couple of pieces of high density boards which sandwiches a PVC strip(from an electrical conduit). This is installed(ie glued), at an angle, to the base of the plane like so:


The angle (the motor slightly pointing down about 5°) is done to offset the forward and down effect of a higher mounted motor. Doing this angle offset will cause the back of the main wing to have a slight down push forcing the leading edge of the wing to pitch up.

Once the motor mounting is done.. the section where the main wing is attached to the fuselage needs to be made.


The image above is upside down and shows the CF rods that’s used as the scaffolding for the wing base as well as the CF rods where the rubber-bands will be attached. I sure hope its sturdy enough!

Finally, I began making the rest of the fuselage. The space inside is big!


A deeper look at the cave..


Its beginning to look like a real Skywalker:


So far i’ve added about 50g at this point.

Project SBSW (update 3) — wing design disaster!

I began working on the main wing again today and decided to cut the two  1m CF tube spars in two and just stick a bamboo barbeque stick in  between, like so:


Bad idea.. this means that the load and wing twisting stress will be focused on the contact points of the bamboo spar and the CF tube which can mean disaster.

At this point i couldnt really revert to using the whole CF spar as the halves are already well glued to the wing. The only option therefore is to just join the wings together permanently and charge this to experience.. $%@$!.

Still about 75% complete.. the main wings now weigh about 320g.. it will most probably weigh about 450g eventually which means I have less than 100g to complete the fuselage.  Doesnt look too good, at this rate the plane will probably weigh 1kg empty =S