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Apr 08, 2012, 05:03 AM
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Build Log

"Super Simple V" wings with a KFm section

I wanted a nice and easy slow flying V wing, built with no tapers, no spars, and powered by the Blue Wonder type of motor..
This I am calling a SimpleV
you can put the motor in a slot or to the rear, even on the front, it doesn't matter..

I am now making a modified shape, called the DeltaV which has a 3.5" nose extension with two sweep backs.. instead of the parallel chord wing
The first sweep is from the point of the nose and goes to the midpoint of the wing as it would be on the simpleV's constant chord wing.
This nose extension gives more room to layout the gear... and makes getting the COG easier...

For my first SimpleV , the constant chord wing, I decided on a 6mm depron build with direct lamination of the layers ..
The leading edge got a 30 degree sweep back.. and I made a prop in slot version

The span you get, depends on the size of your depron.. I used some of the dark stuff which had a width of near 800mm.
for a different board width keep the angles and layer chord widths the same..but recalc the COG on here

And drew it up as follows
Last edited by davereap; Jul 01, 2016 at 06:55 AM.
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Apr 08, 2012, 05:03 AM
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marking and cutting.. first build a KFm4... 3 layers
The main sections are measure and cut..

For an 800x1200mm board
Take the board and put a center line up the length...
At the center line....Measure in inches...9....4.5....4.5...2.5....mark at each spot.
At each edge.... mark up 9....9...4.5....4.5......2.5
Join the dots to make the V's and cut out

The remainder of the parts are.... 2x fins ...2x V fillers ....1x lower central filler the PDF
and the 2x lower splines which are simple 1" strips cut the length of the lower filler and angled at the leading edge..they can be cut from the waste triangles along with the fins etc..

also below are the sketchup models in the zips
Last edited by davereap; May 06, 2016 at 05:16 AM.
Apr 08, 2012, 05:04 AM
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My initial build had to be modified, taking the motor further back to get a better COG..
take note the pics are a bit mixed

The method is to first laminate the two outer front layers to the main central layer..
Then add the two long V fillers at the center.From the parts file.
Cut out the main prop slot..
This starts imediately behind those filler sections and is about 1" wide.. mine was long enough to take a 7" prop..
Next ..a chop out where the motor will need to be, so enabling the prop to sit central in the slot.. this will cut a bit out from all three layers, and can be seen in pic5
Now fit the motor mount by cutting out a slot, start by going in through the bottom layer and the middle layer..the top layer should not be cut..
Remove the unwanted foam from the bottom and main the mount is a good fit and hot glue or epoxy your mount in place ..
When the mount is in you can add the lower center layer from the parts file..this locks in the motor and strengthens the center where youve been chopping...
The two 1" splines are fitted either side of the lower center filler layer..see pic6
Pic 6 is untidy because it shows a lot of odd fitted bits, all needed to fill in where I moved the slot and motor
Last edited by davereap; Apr 08, 2012 at 12:33 PM.
Apr 08, 2012, 05:05 AM
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Hopefully your motor and prop now fit as seen in pic 5 above..

Elevons... first fully tape cover them, this will stiffen them and make them flatter, apply the tape and burnish it down whilst keeping the elevons flat on a bench or glass surface.. chamfer the main layer and the elevon and hinge them with tape..

As can be seen I use different colors top and bottom, this does for the orientation and decor..and tape will make a depron layered wing nice and tough

Leading edge... I have only given it a quick chamfer on the outer layers to make it a bit sharper.. likely a full symetrical sharp edge will be nicer...thats up to the builder.. shape it and then tape it.. see the pics above... never leave it very blunt...
Last edited by davereap; Apr 08, 2012 at 01:04 PM.
Apr 08, 2012, 05:05 AM
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Tip fins
I fully tape cover them before I glue them in place..
Make sure your wing tips are nice and staight, trim/sand if needed and glue the tips on... about 3/4-1" hangs below the wing..

Cool Melt Glue...
Where I make butt joints like wing tips and the splines I run a bead of glue around each joint..I will also use clear tape along joints as a reinforcement....Cool melt is also used to hold the servos tight after I have cut them into the wing
Do not run any cool melt or tape along the wings KF step laminations , it is not needed , and it will spoil the sharp step and be detrimental to performance

3 Strips on top to hold down the battery and so I can use a velcro tie down ...
Bits below for the REC and ESC

RC placement.. check the pics for an idea of where it has worked for me.. my servos would have been better further out, as they were cut in before I had to move that slot back.. the rest is fine and as seen in the pics the COG is at the spot shown in the calculation in post 1
Last edited by davereap; Apr 08, 2012 at 01:08 PM.
Apr 08, 2012, 05:08 AM
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Span...31" and a bit... (The board width)
AUW 9.25oz
Area...2.375 sqft
Wing loading...3.9 ozsqft
Motor a 1300kv Blue Wonder
Orange spektrum type REC
500 mAh 3 cell Tipple lipo.
prop 8x4 cut to 7X4 .. GWS type
servos 2x towerpro sg9 type

COG 6.8-7.1" from the nose.. lucky I was double checking..the original cog calculation had altered the sweep angle so ive now posted two new results that actually take the COG a lot further forward.. now to get the spot the 500 3 cell battery goes here

Try that COG calculator for your self.. input all the changes the angle from 30 to 33.. you then have to re-input the 30 and update to get the correct result... weird...
Last edited by davereap; Apr 09, 2012 at 01:32 AM.
Apr 08, 2012, 05:10 AM
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waiting on the weather now
Last edited by davereap; Apr 08, 2012 at 01:44 PM.
Apr 08, 2012, 06:34 AM
When pigs fly rc
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Cant wait to see what you come up with. I love those little motors!
Apr 08, 2012, 09:40 AM
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Dave! Your the man for slow flight!! And just when I was sketching up some wings for ideas on something slow and I find this!! You have great builds from the Mini Heart to W-wing...and I am patiently awaiting this one too!! Curious on how it'll fly as I have several of the 1300kv's doing nothing.

Apr 08, 2012, 11:52 AM
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Nice simple build, Dave! Love your planes! It will be intersting to see how this wing flies!
Apr 08, 2012, 01:51 PM
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I am sure with a KFm4 it will go well, there is 12-14oz thrust with a 9.25oz model..
So it will go up ok...Basicly its just another zagnutz version.. but with a wider chord.. there's nothing new here, just a simplified build, with a lowish wing loading for slower flight
I supose the bigest change is a prop in a slot, with the elevons going to the center they will be in the prop wash so more effective

I am trying out a new dx6i radio on this one.. a cheap radio and compatible REC .. I had fun trying to get it programmed last night.. and finally resorted to the manual.. but its setup now..
Apr 08, 2012, 04:49 PM
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Hi Dave,

Looking very good.

Thanks for the plans and explanation.

will have to wait thoug.. still have a W-wing and heart on my to-do list...

Keep em coming.. lol


Apr 08, 2012, 07:51 PM
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Though nothing new, it's something I didn't think! Good luck on the maiden and the quest for slow flight! Should be awesome. Awaiting the results.

Grats on the DX6i! It's a relatively good Tx to use though limited. Have one and it's my main workhorse for most scratchbuilds but limited with 2 mixes and less programmable options when you delve deeper into scratchbuilds.
Glad you got the Elevons working as the DX6i has a bogged Elevon option with limited throw. You need to also activate the Mixes to get them to travel further...thus using up all mixes...sigh**

Best mod I did to it was throw in a Backlight!!
Apr 08, 2012, 10:29 PM
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Just finished another "inverted Y" shaped plane this weekend. Added the KF layer to the top of the wing. Comparing this plane to another w/o the KF layer, it appears that WITH the KF layer you have to re-balance to move the CG FORWARD about 1-2 inches.

No big deal; just had to re-position the ESC, RX and Lipo.

Question: In general, does adding a KF layer require an adjustment in CG? Is the adjustment generally FORWARD?

Or is this just a reflection of "no two foamies are identical"?

I should note that the first plane (w/o the KF layer) balanced perfectly at the point indicated by The second, (with the KF layer) needed the CG moved forward.


PS: ANOTHER great looking build, Dave. Good luck with the maiden...
Apr 09, 2012, 01:00 AM
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Firstly did you check that the COG calculator didn't alter the sweep on your first plane, as it did on mine, and do a poor calculation from that change..
I inputted 30 degrees at the start and it altered this to 33 degrees and as a result the COG was way off..a lot further back than it should have been.. so if I had tried flying it like that, I would have been moving that COG forward, likely cursing...perhaps blaming the KF

Ive not noticed any major COG changes with and without a KF section, but I usually stick a section straight on, so I don't have the flat foam model to start with..
I did add a KFm4 to quite a few models, but always went with the recommended COG and found no change was needed.
models KF'd.... Nutball, dart, yak55, F22, normally the KF just improves the feel/stability of the model...The only one it really made a very significant flying difference to was the RET Dart XS.. after adding a KFm4 the model wouldn't roll on went extremely stable...However I then added ailerons and it rolled a treat.. the dart has high dihedral and shouldn't have rolled that well on ailerons..but it did..

Thats part of the reason Ive been playing with the high dihedral W wings, they roll well with the KFm4 on them, they are highly maneuverable, but they are also very self stable..that sounds contradictory.. but works great..

DX6i... I didn't find the elevon throw to be a problem, But I did have to resort to the book to get the throws going the correct way... It was a case of the aileron and elevator servos not being plugged in the correct slot.. the aileron goes on the left wing side and the elevator goes the other... on my futabas I can make the servos go whatever way I choose..
The other bug is that when elevon mixed the dual rates are not individually adjustable..DUH! went on youtube and there are some good videos there..I now see where I was going wong..all is now good
I bought the DX6i to operate some of the eflight and parkzone models I have.. a Blade and a couple of the micro models planes..Now they sell some very cheap REC's that are compatable I have added these to my options
Last edited by davereap; Apr 09, 2012 at 01:53 AM.

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