#18 Model Airplane Building Clinic >> Swanyshouse Primo 40 - Page 4 - RC Groups
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Nov 27, 2012, 08:16 PM
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I've got half the wing covered. Taking a break. Might finish it tonight... or maybe tomorrow. That'll be it for the covering.

Decals will be in the mail tomorrow (Callie is fast.) Ordered up a pair of 4S/1800 Turnigy Nanotech packs from the USA warehouse, so those should be here by the weekend. With the motor moved forward, I figured 15 oz. battery weight might suffice. In my book, that's still a lot -- 25 oz. of power system in 60 oz. plane.

Decals will be applied before final assembly. There's a bit of an art to that, it mostly involves laying them down over a film of Windex or soapy water, and then slowly and patiently chasing out the fluid, along with the wrinkles and bubbles.

No reason it shouldn't be ready to fly in another week or so.
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Dec 01, 2012, 10:21 PM
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Callie comes through as usual. Have decals for elevator, h-stab, and main wing under-side left to do, then on to final assembly. Had our first "sticking" snow today, so lawdy nose when it'll fly... HobbyKing (usa warehouse) dragging on the lipos...
Dec 02, 2012, 02:30 PM
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The rest of the decals from Callie have been applied. Just a bit of trimming to do.

Final assembly will be a trick, not at all like anything I've built before. Ailerons will be hinged afterwards.
Dec 03, 2012, 10:17 PM
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First moment of truth... final assembly. Mix up a big batch of slow-curing epoxy. Mix in baking soda or micro-balloons. Apply to mating surfaces and push it all together. I used rubber bands to apply some pressure where I could.

I have some doubts about building a plane around a fiberglass tube. But I guess I need to take comfort in the general popularity of these planes. I'll have a better feel for it tomorrow when the epoxy is cured.

Batteries from HK arrived today. Swapped the connectors over to Deans and built myself a battery-parallel connector. Hoping to have her finished by the weekend.
Dec 04, 2012, 11:01 PM
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Tonight: removed tape, rubber bands and protective stock and checked it out. Seems solid, my concerns have been quashed for now. Installed servo horns in ailerons and got both ailerons hinged. Aileron servos installed and centered. Fishing the wires was no problem.

Department of Shoulda Done That Earlier: When building the fuselage, build a "hole" to pass a servo lead through. An aileron servo lead, specifically. You just need to give the covering something to adhere to, wherever you choose to run that servo lead through the fuse.

Tomorrow: Hinge rudder, finish up all servo and linkage installation. Then start in on power system as time allows.
Dec 05, 2012, 10:04 PM
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One more evening and she should be ready to fly. She's standing on her own three feet for the first time. All servos and linkages installed. Motor installed and briefly tested.

I needn't have bothered with those two new batteries -- they weren't heavy enough to balance the plane. What you see in the pix are a 4S/2200 and 4S/2600 that were already on hand. Their combined weight is 19 oz. The plane's AUW will be right around 65 oz - no light-weight, but well within the stated specs (4 to 4.5 lbs.)

All that's left is to install the receiver, dress up the servo leads and find a place to locate the ESC.
Dec 07, 2012, 11:21 AM
Rob H
rph1225's Avatar
Can't wait to hear about the first flight. I just finished an E-Mojo 25 and by far, it is the best plane I have ever flown.
Dec 08, 2012, 09:37 AM
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Not flying today, for sure... 43 degrees with a steady cold rain and fog. Ugh.
Dec 09, 2012, 04:54 PM
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She has flown. And lived to tell the tale. It was a bit chilly out, around 45 degrees, with a very mild breeze blowin'. Sun was out early, and later as we were leaving the field... but not for the flight itself. I'll have a video whenever my bud gets around to posting it.

Felt a bit underpowered. I hadn't bothered with the power meter before the maiden, but used the 11 x 7 recommended by Headsuprc for this motor. Back home I metered it and found that prop only gave 500 watts on 4S/4800. But a 13 x 6 gets me up to 700 W without any trouble. Will try 12 x 6 as well.

Even so she handled herself well. I didn't push the envelope. The Primo is my heaviest 3D plane by a good margin, so she'll take some getting used to. It's a good pound heavier than my ExtremeFlight Edge 540 (48") and I can see with the proper power she's going to be a monster.
Dec 09, 2012, 09:38 PM
wood is good
loNslo's Avatar
The graphics really came out well.
Dec 09, 2012, 10:48 PM
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Congratulations on the maiden. Quite a feeling eh. John
Dec 10, 2012, 12:45 PM
God is my pilot
JimTMich's Avatar
Glad you got it in the air.....
Looking forward to hearing what you think when you start getting comfortable with it.
Dec 10, 2012, 06:47 PM
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Thanks for the kind words, gentlemen. Yes, this plane will require some tuning and getting used to. In general I don't fly profile planes in winter, but as long as there's no fluffy snow blowing around, why not?

I'm hoping she'll be a bit more fun with 700 watts than 500. 125 watts/lb. doesn't cut it for 3D. 60-second bursts of 800 watts are said to be OK for this motor. Next-larger motor size would require further hacking of the motor mount.

There's no getting around the size and heft of the Primo. A "floater" she ain't. My other 3D planes are (in order of decreasing weight) EF Edge, large Sniper, Knife Loop Yak, small Sniper, Skeeter (30"). Except for the Edge, they're all floaty and care-free. The Edge has a more serious pucker factor, and I expect the Primo to end up in the same category as the Edge.
Dec 10, 2012, 07:04 PM
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ace4rc's Avatar
Very nice build thread rafe_b. I as well have the Mojo 60, 20cc gas.
Dec 10, 2012, 07:37 PM
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Some further musings... 12 x 6 prop didn't yield appreciably more current consumption than 11 x 7. I'm hitting current limit before I hit power limit, which suggests I need more voltage. So one possibility might be to go with 5S packs. Or expensive high-C packs that won't drop too much voltage under 15C load. I've got a total of 4850 mAh at 4S, but both packs are cheapies rated at 20=25C, and both are well into their life cycles if you know what I mean.

So far I've only measured power-in and current with a wattmeter. Might be useful to take it outside next weekend and try measuring RPM and static thrust as well.

Overall it was an interesting and entertaining build. A bit confusing at first - that root rib barely makes sense 'till you see how the rest of the plane fits around it. The wing is a piece of art, what with the tapered chord and airfoil. The final assembly took some mental prep and nerve. This is definitely not a Mountain Models self-jigging sort of kit, but if you've built a "short" kit over plans, you'll be OK.

If I were to do it again (for e-power) I'd replace the stock motor mount with something an inch or two longer. And find a way to absolutely minimize the weight behind the CG. Maybe with the R/E servos mounted forward, with push-pull linkage. Or maybe covering the aft parts of the plane with ultra-light stuff.

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