Haven't played with by BNV in some time, prob due to the pretty heinous crash it sustained months back - damn battery fell out while under the goggles about .5 mile out - stayed connected though! Imagine what that does to the CG...
Anyway, hanging with the mini-quad racing geeks out here, some guys have expressed the desire to race some fixed wing, and a few have some smaller wings - Pop-wing, Swift, Sweepwings Flinch, etc. Naturally, I'm thinking a Scaled down Blunt Nose Versa fits this bill.
Office Depot foam is the best I've found out here - a tad thicker, heavier than DTFB - but is well suited for a basher like the BNV.
BNV at 81% comes out to about 37" ws. I'm thinking full Lam on the ODFB, coro winglets. good ol' Turnigy D2826/6 2200v and 6/4, HK939 MGs.
I took my Versa out last week in 20-25 mph winds. I knew it was too windy, but I built the blunt versa so I'd have something easy to rebuild to make stupid choices like that. It took nearly full throttle and a lot of quick reactions to keep from being blown back over the ridge I was flying on. A little over three minutes in I landed. On a second launch a wingtip clipped the lone tree on the hill, I righted it just above the rise a bigger gust hit and pushed the versa down behind the ridge. I lost sight of it and crashed ripping off the motor and ejecting the lead nose weight at battery. I threw the battery back in and did a little slope soaring until a servo broke loose. I love my versa.
^That's what it's all about, Man! This bird can take it - maybe just to repair and rebuild, but I find tons of fun in that.
One of my fondest memories with my Versa is putting Eagle Tree Guardian's 3D Heading Hold trough its paces on take off. Basically, chucking the V like a Ninja throwing star at full throttle to see if it would right itself and fly away. Worked a couple of times.
On Saturday I was flying my BNV and well it just felt strange.
Guess I'd got some snow into the battery bay and everything got soggy.
Once I let everything dry off I opened up the front section to determine if the BNV could be saved.
I removed the damaged front section as well the paper from the top and bottom of the battery bay.
I paid attention wing sections adding foam pieces to prevent the sides closes to the battery bay from crushing down.
Even with the repairs done the wing was "floppy" a lot of strength was gone so I opt'd to try the corsply.
The new pieces were glued to the sides where I'd put in some formers.
At first I was going to offset the camera but then I just decided to centre it.
Added a double layer bulkhead increased the stiffens of the wing hugely.
You can also see a fresh piece of foam board on the belly covering off off the battery section all the way to the spar.
I will most likely redo the rounded nose section or at least cap them off so no snow gets inside.
Added new bigger hatch.
A side benefit of all of this is I no longer have to add the 3 allen keys to get my CG.
Let's go flying.
After 2 LOS flights to setup the trim and balance I went FPV flying.
The first time doing fix wing fpv since late 2014!
My brother had a big power setup he never used so I decided to make modified BNV to fit this heavy gear.
Motor: NTM propdrive 35-48 1100kv
Battery: 4000mah 4s
Prop: 11x7 APC (Note it's a 9" prop in the pictures)
There were a few issues highlighted by other users so I wanted to achieve the following:
Easy CG setup - this motor is heavy so it needed to be situated further forward.
Prop space - extra had to be cut out to make room for the 11x7 prop.
Fuselage space - A fully custom fuselage meant I could have quick access to all the components
Strength - Using a two piece design with a "jigsaw" joint strengthened by a one piece motor mount and skid plate.
Yawing - Most fins on wings are perpendicular to the yawing pivot point, I wanted to create tail fin properties by stretching the fins rearwards.
Here is the two piece "jigsaw joint":
One piece motor mount and skid plate:
This is the fuselage lid made in a similar way to the wing airfoil:
The fins are long and needed stiffening up, I embedded a ring of cocktail sticks into the foam and then glued a second piece of foam over the top. This has created a very stiff yet light fin. This technique can be used in the spars if you glue a cocktail stick top and bottom. Which transfers the maximum tensile stresses through the cocktail sticks (This is how a steal "I" beam works) adding a lot of strength with little extra weight:
This is the finished fuselage cover held in place by 3m Dual Lock (similar to Velcro)
The fuselage was made up of layers of foam to build a wall and then sanded to shape, it also provides good impact protection:
The fins give that racer look:
The nearly finished product, just need to maiden this thing now!
Ok so maidened the above today, Wow this things got some serious power!!! It was rapid at 40% throttle.
I have got some 9g servos on there which don't seem to be man enough. I gave it a blip of 80% throttle and it struggled pulling up, it flew real nice going a bit slower. Going to have to beef up the servos and try again.
What I was really happy about is how much control it had coming in for a landing, slow with lots of lift even with the powerhouse onboard.