skaliwag

My Feedback: (1)

The plan for the Simple 400 shows no dihedral.. Just build it flat, upside down.. Comments from you people that do the fast, turn left thing.

Oh .. what abrasive mechanism do you recommend to use to get the zits of the foam cores?

Toad

The wing is built flat, upside down, if the airfoil tapers in thickness along the span, this way, a small amount of dihedral is incorporated along the bottom of the wing with the top of the wing remaining flat, spanwise. It works well, THe airplane comes out of your hand at launch and trys to level a bit with no input. They say it induces less drag than a bent wing.. I cant comment on that because I would not know. For the foam, I use one of those flexing sandblocks, just a light go-over, then into the bag it goes with the sheeting. The Purple/red Scotchbrite pad works well with a light touch also

hfenn

I don't bother to remove them. Underneath a low temp covering like TowerKote, they look like rivets!

Larry Driskill

When working with foam these are real handy. The Big Box stores have them too.

http://www.kittingittogether.com/shop-staples/

MJD

My Feedback: (1)

I use a worn down thin flexible sanding pad. As mentioned, scotchbrite works too. Otherwise, as there are no compound curves, make a little sanding block from 1/4" soft sheet and 3M77 some 180-220 grit to it.

Mine is flat across the top, and totally locks into attitudes and headings. No pitch, roll, yaw, nothing at launch, just straight out pretty as a picture.

Totally KISS principle airplane that flies very, very well. Both I and cohort are making thinner wings for ours now and will report once checked out.

Mine was given a 1/4" wide impression at the top and bottom high points of the airfoil, and I laid in a strip of CF tow with epoxy. The wing nearly does not flex now, and I pull full boogie hard turns with no sweat or odd habits. The fuselage was also silkspanned and a light layer of Kevlar veil on the front belly part for landing abrasion resistance.

AUW is 19.6 ounces with an E-flite Series Six 2700kv motor, 2100 3S LiPo, and four channels. I started with a CAm 5x5, but the APC 5.1x4.5 is a better match for the aircraft. More pull, and higher top speed too, Doppler says 125 level. Glides long, fast and flat, but it slows down enough for easy landings. I fly out of a tiny community center field and git er up and down no sweat.

MJD

skaliwag

My Feedback: (1)

More info on the CF band please. Cloth or strip?

MJD

My Feedback: (1)

It is simply one strand of CF tow from a spool that I "borrowed permanently" from work, we used to filament wind CF rocket motor cases you see. Actually the spools get to the point where they are down low enough that they are worth little else, and that is where the scrounging modeller scores. The tow that Dave Brown and others sell is generally the same [excrement], different bag.

I glued some sandpaper, forget what but 150-220 grit, on the edge of a piece of 1/4" sheet, and used this to gently sand a depresison in the foam top and bottom. I brushed epoxy laminating resin in the groove, laid the tow in, and brushed enough resin in to wet it out. IIRC I set some scrap film backing on top, a piece of foam, and some weight. If you can pin it out from the tips an inch or so and put some spanwise tension to straighten it as it cures even better. If you try to bend it around 90 at the ends and tape it with tension forget it. There is also a piece of 3.2 oz cloth reinforcing the center section, mebbe 3" wide.

If you were going totally nuts, and I'll try this on the next set I bugger with, you'd cleanly saw the core in half spanwise at the high point, bond a 1/16" end grain spar web to the entire cut face, then rejoin. Then, cap it with CF tow. Good luck bending it! But the foam, while decidedly lacking in compressive strength, does provide enough compressive resistance to result in a stiff wing, though it will flex a hair if I pull on it. That's just the foam squishing ad returning. Go too far and it will yield though and won't return.

As I hinted, I've abused this thing totally - full high rate Lomcevaks at top speed (looks like a starfish fired out of a cannon) and pylon turns as hard as I could make them. It ain't broke yet.

BTW I continuous hinged the tail surfaces, there's some detail in an old thread somewhere. I sawed slots using a Dremel router table and that little crappy saw blade they always give you. By lowering the dremel/blade to where the blade just rests o na strip of 1/16" ply, it will saw straight as an arrow. I then glued scrap super coverite in as the hinge. Nice thing about that is it doesn't absorb CA and get stiff and then crack and fray like bare fabric could.

I gotta document some of this stuff better and post it. The odd thing I do makes sense and results in what I see as easily-done improvements.

Also, I faired the nose in best I could so it matches up to the spinner/adapter. Right now I'm just running with the bare shaft and prop adapter sticking out of the spinner ring, since I trashed my spinner adapter. That's what it looked like when I clocked it.. so dunno if the spinner adds much or not yet. Looks better though of course.

Didja see the crappy video I posted on YT? You can almost make out the model during some passes, but you can get a fair impression of the speed. Handing a point-n-shoot to a buddy and saying "film a fast airplane" gets predictable resulkts every time.. [:-]

MJD

vicman

My Feedback: (10)

I got rid of the zits by slowing down the wire pass. It amazed me how much better my cores started coming out. Now they look almost extruded or molded. There is a neat how to on the NMPRA site for laying up a v-tail that shows how to use plastic sheeting (I use poly drop cloth from Lowes) if you don't have a vac system.

skaliwag

My Feedback: (1)

Is there scientific reasoning why the ailerons are not full span?

Toad

surface deflection creates drag, thus ya slow down some, so you only want as much aileron as needed to race with.. hence partial span.. IF you are intending on just going fast and having a lot of high speed fun, then make them full-span or throw em more.

skaliwag

My Feedback: (1)

Wing tips... I see on the latest go fast renditions that they are swept back and pointy at the t/e.
Is it worth it on the porkie ACE foam wing?

MJD

My Feedback: (1)

Not in my opinion unless you like the looks. Plain old sawed off tips aren't all that bad, and if you make fancy tips you have to do them somewhat right to see a gain versus something that looks cool. If you want to go faster, change the 2415 even just to a 2412 or 2410 or use a clean glider airfoil like an RG14 or 15 or similar. Make two wings and a saddle adapter..?

If I was me I'd glue a tip rib to the end of the wing to keep the ends tidy though. On mine I forgot to mention I also laid .003" CF uni along the bottom of the TE so I could trim it down nice and thin just for fun. 1/64" ply is good too of course. And if you are ambitious, from personal experience I would inset something into the LE apex for ding resistance.. if you've seen any of the recent pics of mine you can see a few field patches of Al tape. It clocked 125 on about 375W with the spinner missing and three dents in the LE.

If you want to go faster than mine try a Mega 16-15-3 and 5x5 or 5.1x4.5 prop. The Eflite motor I use is not too far away from this but not quite as silly.

MJD

MJD

My Feedback: (1)

I think you should keep the airflow clean at the tips, and the roll rate as it is here is plenty quick for anything. On high rate I get what, 2-3 rolls per second, and maybe 1 on low. Besides, if they are too long then you get more flex.

MJD

skaliwag

My Feedback: (1)

Moving along with my version of the S/S 400.
Asking which aileron servo to use.
Where to get C/F strap for the wing.

flyinrog

My Feedback: (1)

If your just gonna go fast and turn left you only need one aileron anyway.......Rog
open up one of Bobs hot shot kits and you'll see..

combatpigg

My Feedback: (3)

I've tried the single aileron on 3 different planes and found with all 3 that the plane didn't have enough control to turn up wind, even with a lot of throw dialed in. When you are flying at or near 70-100 mph there's enough control, but inevitably the plane will need to glide home and has to be able to negotiate the wind.
Another reason for partial span ailerons is decreasing the possibilites for flutter.

skaliwag

My Feedback: (1)

I've found the C/F strap now which servo to use for aileron?

MJD

My Feedback: (1)

If you are flying with an .049, this is not going to be a rocket and I sincerely doubt you are going to have aileron flutter problems. I have gobs of roll rate on mine with ailerons that run 2" from the tip to 2" from the root. It is indeed nice to have lots of authority when things get slow. Bear in mind is that this aircraft has a 15% thick airfoil, and is primarily a sport aerobat. You can set it up with one aileron if you like but you will be robbing yourself of a lot of flying capability IMHO. Mine has rudder as well and does crazy lomcevaks and other random contortions with the sticks cornered. It's only fast because of a ridiculous amount of power, I am not sure it would go that quick even with a ripping 1cc glow engine.

I don't have an aileron servo suggestion mind other than I would say that you need something one step above an HS-55 for durability. I use a Dymond D60 because I had a couple lying around and they are strong and light.

MJD

skaliwag

My Feedback: (1)

Will these work for servos? Only need 2

http://www3.towerhobbies.com/cgi-bin...?&I=LXHHC2&P=7

http://www3.towerhobbies.com/cgi-bin...&I=LXHHB0&P=SM

MJD

My Feedback: (1)

I can tell you that by the specs they both have plenty of muscle for the job. I would go for the 10g Naro fast: 24 versus 25 oz-in, 10g versus 14g. I don't know what other major differencees there are, i.e. what does the "max" imply? If there is some reason out there not to use these GWS servos on 1/2A models, I don't know what it is - but I'd like to because I have 4 I recently decided to harvest and use in 1/2A's. I recall mumbles about being made for the vib environment - but about whose servos I aint sure. But the numbers are good - 24 oz-in is gobs of power and at 10g the power to weight is decent too. FWIW I've not had a problem with a GWS servo yet, mine are all flapping big depron surfaces on indoor lekkies though, apples to oranges?

MJD

SGC

Ive used/use quite a few of the narro max servos in .15ci models, the only time they stuff up is in a hard arrival and a control surface puts too much load back into the servo- stripped gears, a new set of gears and there back and fine. Also use the narro servos in flying wing slope gliders without probs too. great servos
Stewart

MJD

My Feedback: (1)

Good to know they are working on a glow powered model! That's the Naro Max, do you think the others are okay too, or do you know what this "max" term means, if anything?

MJD

SGC

MJD ,
Its been some time since I purchased GWS servos , but from memory the MAX series have a higher torque and slightly slower speed than the similar std servo (different gear ratios), I also use a few of the Narro Max BB servos and they too are great.
Stewart

skaliwag

My Feedback: (1)

GWS servo specs

http://www.gwsus.com/english/product...ub%20micro.htm

KidEpoxy

The torque numbers arent the problem with common parkie servos,
its wondering how long them little 400tpi nylon teeth on the gears will last against engine vibe