flyingwings.co.uk Venturi FPV and laminating

[CurryKitten]

If laminating takes that long, it's a nice opportunity to put your GoPro on time lapse mode and capture the epicness of the build.

[ROVguy]

We didn't particularly rush it. I suppose it's down to how quick the lammy works and how well the iron heats up.

[krikey]

@joshua: I'm using the following:

2 x 2200mAh 3S LiPos
2 x Hitec HS-645 MG Servos
1 x D8RII-plus 2.4GhZ Receiver with telemetry
2 x 60cm 2.4gHz extensions for D8RII-plus
60A brushless ESC
E-Power BL2815 Brushless Outrunner Motor 1400KV
9x6 APC style prop
ImmersionRC 600mW Video Transmitter
Circularly polarised Skew Planar 5.8gHz Antenna
I'm undecided on Autopilot right now but may put the Storm OSD in there as its quite small. Ideally a Ruby or a RVOSD.

[ROVguy]

Hey Krikey, had the wing up again today for more testing and trimming. You REALLY have to get the COG right! I put the best part of a 100g of weight on the nose to get it flying sort of ok.

Right after an incident today, make triple sure the screws holding the motor to the motor mount are secure!!!! In fact I would definitely loctite them in place, I certainly will! Mine came out mid flight, which bit into the wing and I also ended up losing the prop adapter and prop as well. However, that being said, the motor dangling down and being forward made the wing fly sweet. So in going to remount it on the inside of the bracket ;-)

[krikey]

Laminating and taping is finished and the airframe is much much stiffer now. I noticed that it was harder to laminate the top surface which has more camber on it. The laminate I used was much more forgiving than I thought and I found that I was able to go back over it with my clothes iron and reseat any bits of laminate that had yet to tack. I also carried the laminate across the section in front of the motor on the top, and overlapped it slightly hence helping to strengthen this area somewhat, especially as I have cut out some of the foam to position the ESC and also run the power lines into the space.

If I build another wing however I may try the spray mount step before laminating to see if this makes a difference but the laminate has bonded quite well so far.

To tidy up some of the areas I used the weave packing tape which whilst not sticking well to EPP, sticks very well to laminate.

I laminated the Elevons and used the Zephyr II method of mounting them to the wing, using small bits of scotch invisible tape to start with then a strip of weavetape along the top surface. Then I folded back the elevon so that it was sitting on top of the wing and I then tapes the back of the elevon to the underside. This makes for a very strong hinge as mentioned before the weave tape adheres very well to the laminate.

I then taped the edges of the elevons so that they were nice and strong.

I've ordered some M3 locking nuts,bolts and washers as there were none in my VenturiFPV pack to secure the engine mount to the ply. In addition, I've ordered some M3 metal clevises as again there were two in the pack but Ideally I need four.

[krikey]

ROV, do you have a GoPro and a flight cam in the nose already? If not I would also account for this weight. I was on 190mm from the blunt nose before laminating and taping with 2 x 2200mAh 3S batteries hard up against the interior space.

Is your CofG still at 180-190?

[ROVguy]

My initial CoG was taken with everything fitted Krikey and my test flights were with everything fitted including flightcam and GoPro, hence the reason Ive had to repair the Go Pro so much ;) lol. Just make sure that the wing is slightly nose heavy and NOT tail heavy.

[Brucey]

ROV, do you have a GoPro and a flight cam in the nose already? If not I would also account for this weight. I was on 190mm from the blunt nose before laminating and taping with 2 x 2200mAh 3S batteries hard up against the interior space.

Is your CofG still at 180-190?

Sounds like the build is going well.
Have you re-checked the cog since laminating? It will add more weight to the tail than you think.

[krikey]

When I've added all the pushrods clevises etc then I'll rebalance but yes was aware that lamination would push weight to the tail.

I'm not carrying a separate flight camera so I may use that little compartment to carry some ballast.

[ROVguy]

Hey guys, I've just finished remounting my motor and fixed the new prop adapter onto the shaft. I decided to check my CoG, my god I must have been on something when I last checked it! It is way out!!! Even with motor brought forward and 2 strips of weight on the front! I put tape on the bottom and measured out a scale so I could get an accurate measurement. Its now 180-190mm, god only knows what it was with the motor at the back and minus the weight! No wonder I've been having major issues getting it to fly properly.

I've also noticed that the wing tips over to one side, the side with VTx so I also need to place weight to counterbalance that.

So krikey, when checking your COG, check, double check, triple check before putting the wing in the air... And loctite all nuts and bolts!

[Brucey]

Hopefully now you've got it sorted it should fly like a dream!

[krikey]

Now all the clevises, motor mount etc is installed including gopro in the nose, I need 250g to get cofg at 190mm. which is an awful lot.

I am using 3s 2200s in the centre box but does this sound right?

[ROVguy]

Right, my setup is:- 2x 3300 mah lipos, 600mW VTX, Ardupilot 2.5 with GPS, 2.4 GHz FRSky FR8-SB. Flying camera and Go pro 2. Total weight 2.3Kg that's with 100g at least on the nose. And 20g on the opposite wing to VTX

[philf]

I also had to add 200+gms to balance mine....it still needs more! :o

[Brucey]

Can't remember how much lead mine needed. I've got 2x 3s 3300's and the go pro in its case.
AUW is 2.4 kg. Still glides well and launches easy.