Scratch Designed/Built Sailplane Fuselage

[CHELLIE]

Originally Posted by mclarkson

Brilliant! I'm totally stealing this!

Yes, Great Servo mounting idea Nodd.

[starcad]

I like how you used the jig for the tail section. Wish I would have thought of that several years ago when I built my Bonanza. Very Kool way.

[HO-229]

Nodd,
How high can this model fly... ignoring the fact you may lose sight of it, any idea?
Looks super

Dave

[Nodd]

Originally Posted by mclarkson

Continues to look brilliant. And I've found Blenderm to be pretty much flawless.

Aye, I've tried a few other brands but Blenderm seems to be King.

Originally Posted by CHELLIE

Yes, Great Servo mounting idea Nodd.

Thanks Chellie *smile*

Originally Posted by starcad

I like how you used the jig for the tail section. Wish I would have thought of that several years ago when I built my Bonanza. Very Kool way.

If I had three hands & the patience to hold parts still for hours while they glued life might be simpler. Alas I have to build jigs. Actually thinking up neat ways to hold stuff in place as it cures is part of the fun.

Originally Posted by HO-229

Nodd,
How high can this model fly... ignoring the fact you may lose sight of it, any idea?
Looks super

Dave

The sky's the limit Dave. Yeah I expect she'd easily climb right out of sight & would likely keep going up until either the battery went dead or the air got so thin the prop no longer had something to bite. *shrug* 10,000 feet, 20,000 feet?


Wrapping up the wing (again)
Apparently Untracote doesn't stick well to spackling. So I decided to re-mask the wing & paint the fiber-glassed center area...



Usual thing, took 20 minutes to mask her, 30 seconds to apply the paint...



Next I set about applying the covering...



Transparent white on the open structure, gray on the sheeted sections...



Love the way the light shines through the wing, that should look real nice overhead...



Well that's enough for today...

[Nodd]

The wires don't reach
I've never been one to use pre-made servo extensions as it's not that difficult to solder together a custom length of wire if need be. Here's a great tip I picked up watching Bruce from xjet & rcmodelreviews on YouTube.

First I cut off the servo plug & find myself a spare length of servo wire...



Next I stagger-cut the wires so the connections aren't all in the same spot...



Bare the ends...



Twist them together...



Add a smidgen of solder to each...



Bend em over...



Slip a length of heat-shrink over the whole thing...



And we're good to go. I like this technique, no need to fiddle about insulating each wire separately. Thanks Bruce...



Back to the covering
I added the black visibility panels...



Started work on the outboard panels...



That'll do for now, more soon...

[earthsciteach]

Thanks for the servo extension tip.

What is the wingspan on this sailplane? I'm sure you stated it, but I didn't see it as I scanned back through the posts.

[HO-229]

Ok Nodd,
It’s strikingly magnificent but I must ask… why did you run the V-tail controls outside the boom?
So much grace and beauty...
Your attention to detail has me wondering

Happy New Year
Dave

[Nodd]

The wingspan is 105" (2667mm).

Originally Posted by HO-229

Ok Nodd,
It’s strikingly magnificent but I must ask… why did you run the V-tail controls outside the boom?
So much grace and beauty...
Your attention to detail has me wondering

Happy New Year
Dave

Thanks Dave. Yeah I explained the push-rod debacle in post #70. To summarize; basically I just plain forgot about them when I was setting up the wing pylon & tail-boom. No excuses.

[HO-229]

Nodd,
Nice wire work!
The method I like to use that eliminates the pig tail; I find it helpful for connecting in-line wire (splice). The loop is exaggerated; zero space is in the loop.
Dave.

[Nodd]

I'm liking your loop splicing technique, yeah that gets rid of those pesky pig-tails. Nice tip, thanks.

Got-ya Covered!
Finally finished up the covering today...



I know you probably want to see how she looks assembled but I'm an evil bugger, you'll have to wait until she's complete. We're getting real close though :-)

[Nodd]

Spaghetti for Dinner
I picked up this nifty six pin connector to power the wing...



I wanted to avoid having four connectors, one for each of the wing's servos. The red positive wires connect to one pin, the brown ground wires connect to another pin. Then each of the four orange signal wires goes to its own pin...



I'm still deciding if I should glue this in solid or leaving it loose...



Here's the other end exiting the bottom of the wing...



Shockingly, everything seems to be working. That never happens! *grin*...



Now that the servos have power I can proceed with installing the flaps & aileron linkages.

[kyleservicetech]

Originally Posted by Nodd

I wanted to avoid having four connectors, one for each of the wing's servos. The red positive wires connect to one pin, the brown ground wires connect to another pin. Then each of the four orange signal wires goes to its own pin...
Shockingly, everything seems to be working. That never happens! *grin*...

Now that the servos have power I can proceed with installing the flaps & aileron linkages.

Oh boy!

I've got far to many years experience at work on this sort of stuff. Over 45 years worth before retiring in fact. And, a lot more than a few hundred hours were spent replacing connectors that had reliability issues. Those connectors you've selected really scare the heck out of me. The issue is zero strain relief on the wires soldered to the pins of the connectors. If to much strain is placed on those pins, they are going to bend them at the plastic shell location. Bend them once or three times, and they can break off.

I've used different connectors for my giant scale models. My Giant Scale Electric Cessna uses the 9 pin connectors. The wing is one piece, with ailerons and flaps. That takes 6 pins total. These are available from www.digikey.com, and are available in a number of different pin counts.

I've standardized on nine pins for my stuff. These connectors are well designed, and come with a locking tab so they CAN NOT come apart without releasing that locking tab.

Take a look at my thread on this connector: (These connector pins are also available with gold plating. IMHO, gold plating is not required when the connector is repeatedly connected and disconnected. My service experience shows that gold plating IS important when the connector is buried inside something, and is very rarely ever taken apart.)

http://www.wattflyer.com/forums/showthread.php?t=64209

[Nodd]

You're not the only one who's expressed concerns about my connector Dennis. Although those are widely used in RC they're often anchored directly to the airframe...



With that setup, strain relief is not big issue but as you noted, I'm leaving mine lose. So at the suggestion of folks wiser than I, this is what I did...

I pulled everything apart & started over. This time instead of heat shrink, I used hot-glue to bond everything together into a nice static lump-o-glue...



I figure this both insulates & immobilizes. A little heat shrink finishes her off nicely...



Not as solid as those Digi-Key connectors but I think that'll work. Also I'm thinking I'll probably not remove the wing center section all that often. The center wing isn't all that long so the fuselage & wing could likely be stored & transported as one piece cutting down on ware-n-tare not to mention spending less time at the field setting up.

That Digi-Key site is bookmarked, I'll consider those connectors for my next project. Thanks.

[kyleservicetech]

Originally Posted by Nodd

You're not the only one who's expressed concerns about my connector Dennis. Although those are widely used in RC they're often anchored directly to the airframe...

With that setup, strain relief is not big issue but as you noted, I'm leaving mine lose. So at the suggestion of folks wiser than I, this is what I did...

I pulled everything apart & started over. This time instead of heat shrink, I used hot-glue to bond everything together into a nice static lump-o-glue...

I figure this both insulates & immobilizes. A little heat shrink finishes her off nicely...

Not as solid as those Digi-Key connectors but I think that'll work. Also I'm thinking I'll probably not remove the wing center section all that often. The center wing isn't all that long so the fuselage & wing could likely be stored & transported as one piece cutting down on ware-n-tare not to mention spending less time at the field setting up.

That Digi-Key site is bookmarked, I'll consider those connectors for my next project. Thanks.

That hot melt glue would be a big improvement. As long as you're careful with the connector it should be OK.

FYI, for other readers of this thread, that hot melt glue goes exactly where you put it. It doesn't migrate all over the place like CA will. Word to the wise.

DennyV

[Nodd]

Yeah no doubt Denny, I learned the hard way, CA & electrical connectors do not mix. The stuff penetrates into places you don't want it. Ruined a few connectors before I wised up. Thanks for the tip.

On with the build
I finished hooking up the control linkages...



WARNING: The following technique has the potential to go horribly wrong in all sorts of unexpected ways. If you try this take extreme care.

Although pretty close, I noticed the gap between the fuselage & spinner was pretty uneven...



Then I had an idea how to even that up. I slipped a piece of sandpaper onto the folder's hub...



Then I powered up the motor to around 10% & let the sandpaper do its thing...



That worked pretty well, nice even gap...



With the prop installed I stuck her up on the balance stands. Weirdest thing ever, she balanced perfectly, no extra weight needed. How often does that happen, especially on a scratch designed airframe?..

[Nodd]

And then I realized there was nothing further to do...

COMPLETE!

Seven months in the making, she's finally ready to fly, woohoo!























No matter what happens from here on out, that was a great build. I've learned so much, couldn't have done it with out you folks here online. A heart-felt thanks to everyone who contributed.

wingspan: 105" (2667mm)
weight: 69 oz (1956 g)
wing loading: 12 oz/sq.ft (38 g/sq.dm)
cubic loading: 5.21 oz/cubic.ft
stall speed: 17 mph (28 km/h)

I was hoping to maiden her this Wednesday but the forecast is for rain/snow. I'll keep you posted. And yes there will be video, flight reports & all that good stuff. Thanks again everyone.

[kyleservicetech]

Originally Posted by Nodd

And then I realized there was nothing further to do...
105" (2667mm)
weight: 69 oz (1956 g)
wing loading: 12 oz/sq.ft (38 g/sq.dm)
cubic loading: 5.21 oz/cubic.ft
stall speed: 17 mph (28 km/h)
[/INDENT]I was hoping to maiden her this Wednesday but the forecast is for rain/snow. I'll keep you posted. And yes there will be video, flight reports & all that good stuff. Thanks again everyone.

Wow oh Wow

That is an impressive model and impressive build!

[vicrider]

Man that thing is a work of art. Really really enjoyed this thread. Good job and good luck on your maiden.

[CrimzonRider]

Simply Amazing Ship! She gotta a name yet? maybe I missed it....
Have a good one and good luck on the maiden.

cr

[mclarkson]

Gorgeous! Congratulations. I'm betting it'll fly.

[gramps2161]

Nod another one of your stunning builds! I've enjoyed silently following along on this one I always learn something new when a build thread is going.

[earthsciteach]

Stunning! Thank you for sharing. I learn tons from your build logs. Best of luck with the maiden!

[Stevephoon]

Another great build and build thread Nodd! I'm always learning things in your builds that help. I'm planning on buying a bunch of three conductor servo wire for splicing in instead of using servo extensions. That's another good idea. Cheaper and lighter!

Steve

[riverrat]

Nodd

Kudos, & good luck
on the maiden!

Regards
Jimmy

[JetPlaneFlyer]

Magnificent work,

Best of luck with the maiden, please dont forget the video