Electrifly Pluma 3D Build

Started building my Pluma 3D. I'm REALLY stressed about how thin the 3mm foam is on this. It folds/breaks so easy, I'm pretty sure this plane isn't going to last nearly as long as my beloved EPP Piaget, but I sure love flying the Pluma 3D on my RealFlight sim.

The build seems pretty straight forward, so far. I like the aileron connectors and it wasn't as bad as I thought it was going to be getting the linkage lengths all matched. I'm pretty disappointed that my CA glue is eating the foam (I haven't had to worry about foam safe CA ever on any of my planes...and actually thought that the ZAP CA+ was foam safe...nope!). It is eating a little of the foam, but seems like if I hit it again after it and accelerate it pretty quick, it stops the eating.

I got some foam safe CA, about half way through and it went a lot better. Finished most of the work after about 4 hours of careful work and test fitting and stuff. I was missing a couple small pieces because the bag they came in was split and everything was loose in the box, but seems like I can make do. I used a 1300kv Hextronik Outrunner, commonly called the blue wonder and weighing in at around 24g (with prop saver and mount). I'm also using the HXT500 5g servos for the elevator/rudder and HXT900 9g for the ailerons, a Turnigy Plush 10A 9g ESC, and finish it up with a GWS Pico 4ch 72Mhz SC Rx.

Looking like the plane dry weight with everything finished (ESC, motor, servos, and airframe) is going to come in at 7.5oz (that is with the airfoil brakes and landing gear all on but no Lipo). My 460mAh 2S1P Lipo's are another 1.0z, so I think it is going to be pretty heavy (though the Electrifly site says it is 8.4-9.5 oz plane). It sure seems a lot more fragile than my Piaget, but I guess I have a top and bottom wing now, which makes it a lot heavier. I think I just figured out why there aren't a huge amount of 3D bipes out there...

I'm still sort of trying to puzzle out how/why these planes (even as super light as they are) "fly" without any airfoil...I asked my fluids teacher the same question 18 years ago about paper airplanes. He told me, technically they aren't "flying"....huh. Bernoulli might want stop by and pick up Reynolds to come watch me at the park some time...






Update 6/16: I got the last CF rods all glued and hit the landing gear with an extra coat of CA glue because I've heard they are a big weak spot. I put on the spoilers, even though it is the maiden, and I'm flying outside. Grin. I like a challenge and plus, I love the slow speed descents these help make. Got the 2S Lipo in (yup...even risking that) and the CG set about where I think it should be at 65mm back from LE. AUW with 2S 460mAh Rhino Lipo is 8.6oz. 8.5oz without the spoilers.

By this time, it is about 10 minutes after sunset, but it is still light enough. Winds are about as calm as it gets all day (always gets nice about this time of night). Crap...they have the sprinklers on at the park across from my house. But that's ok. Only half of it (it is only 100' x 200' at most, and has trees on 3 sides with houses and everything). LOL. Check throws again, everything seems ok, but the ailerons are bowing on the push side at extreme throws. Looks like the spoilers pulled the push rod ties too tight together and it might be binding a little? Oh well, gotta try this before it gets dark.





Throttle up and off she goes...slugishly, but not erratic or anything. CG looks good and everything seems pretty true. Only need a little rudder and aileron trim change. Rolls are slow (compared to my piaget at 140% throw). Try a couple high rolls, knife edge...wow...that thing holds a line very well. Doesn't climb too well with the 2S. OK, try a nice slow elevator drop back toward me...wow..that thing will float with almost no speed. Bipes RULE for wing loading! Throttle up hard into a hover...hum...that didn't go as fast as I thought. OK, it is taking almost full power by now to maintain hover. Obviously, 2S with this blue wonder 1100kv and 9x5 GWS prop isn't going to cut it. Bring it around and slow harrier it in. Wow...flops down nice and no crunchy sounds. Walk over, everything is fine.

Swap out to 3S, throttle up (MUCH better). Let go...wow...that thing is now crusing (much closer to my Piaget, though not quite as fast with 3S on full throttle). Bring it around in a slow descent...nice, not much change, but I can tell it wants to drop nose now with the 3S a little more and roll right, which is the side the lipo is velcroed to...hum...have to probably play with that a little. But first, try a hover. Power into a vertical and chop to about half throttle. Very nice, wow...this thing holds a hover nice....whoa...ok...still a little nose heavy, because once you start sliding back down, it wants to flop over and roll all unpredictable (need CG pushed back a little more with the 3S, obviously). Try taking off the spoilers, and the ailerons get WAAAAAY better on throws. Now it rolls GREAT. Snap rolls aren't quite as good as the piaget, but they are better. Descents are WAAAAY faster, though. Spend a couple minutes just playing with flat rudder turns close to the ground maintaining flat orientation (I love how that looks). Nice. This thing has very crisp lines and seems to hold 4 point rolls very nice. Maybe my piaget has just gotten so out of alignment with all the gluing that I've come to expect slow gradual rolls and turns at different speeds, no matter how I trim it. Grin.

Burn through another 2S and it is really getting dark. Again, can't hardly believe it almost won't hold a hover at full power, but it is close. have to flop it horizontal to pull out of it and then climb. The 2S is much more nimble/floaty on the slow speed, but it is sluggish for power. Probably need to try my wattsup meter and check couple other props. By this time, I've got the spoilers back on, and I've done it so it doesn't seem to bind the push rods to the top ailerons quite so bad. Better, but this just seems wrong. It isn't unfettered like it is without them on.

1. I think I like my piaget better. Ok, different, and I need to try this more, but...
2. 2S is not real reasonable...at least not with the blue wonder 1100kv and GWS 0905. I may try my old piaget motor...it seemed better with 2S for even a 1oz heavier plane.
3. My one aileron push rod has a very small wire (one of the parts missing) and it has a lot of slop in the control horn. Need to redo the whole aileron push rods, because the small CF supplied is WAY too small/flexible. Still not sure I like the plastic servo differential...it is too flexible and didn't fit over my HXT900 servo arm right. Hope this fixes the issue with the spoilers causing some binding and the pushrod to bow (BADLY in some cases, though it isn't quite as bad anymore after working over the spoilers to provide wider space).
4. Landing gear seems OK. I was worried about this, but it seems to hold up good, so far.
5. I suck at rolling harriers. God, I wish I could get the cadence down better.
6. Waterfalls are not bad. I have some roll that may be the lipo balance over multiple ones, but not too bad.
7. Slow speed floats on this thing rock. I may start to just try to grab it rather than stress the landing gear. There is still a nasty low speed left hand roll/rudder turn that I assume is the lipo balance compared to trimmed out at speed.
8. There is some nasty vibration at about half throttle with this GWS 0905 prop. I may swap over to an 8x3.8 that I've been using on my piaget, just to see how that goes. Probably need to invest in a good prop balancer...

Overall, I like this plane. I have a new/fresh Piaget that I need to probably build, but I was wanting to try this first. I'll give this some more practice and keep playing with it and I like this plane, but it isn't my old piaget...and we'll see how it does in 10mph wind like my Piaget could handle...