combatpigg

My Feedback: (3)

To be displacemently correct {DC}, let us refer to .074s as 3/4A from this point forward, in an effort to appease the sensitivities of those who carry clip on calipers in their shirt pockets [on dates even] . [never know when you might want to challenge a "C" cup claim too, you know]

Anyway, here is an attempt at building a .074 profile that will be able to do it all. Looking for that 2:1 ratio. The profile kind of looks like a SU-DO-KOI, those black stripes on the sticks are where I painstakingly glued carbon strands to stiffen the wood. It seemed to work.

The plane is at the stage where not much work went in to making it almost look like something, but built up ailerons and tail parts will eat up another evening.

Mr67Stang

Okay, we're watching[sm=wink_smile.gif] There will be video of the results right?

combatpigg

My Feedback: (3)

I hope so, if the plane is worth shooting there will be some video. This will be one of those threads that will be left open until the goal is met. Eventually I would like to have a built up 3/4A 3D plane, but for now a profile will do. It might be easier to build foam and depron prototypes? Does a HS 55 look like the bare minimum for the flying surfaces?

chevy43

I thought you said you were going to power it with a WASP?

combatpigg

My Feedback: (3)

Chevy, that was before I had a couple of AP .061s in my "junk" engine can waiting for an overhaul. One of the AP P/L sets ended up in a AME and is pulling my GLH around pretty good now. For now the .074 is the best athlete available. There will eventually be a 1/2A 3D thread, maybe after Tim gets done with that custom .061?

I keep fogetting, now that I'm "DC" the .061 thread will be about 9/16A 3D.

Mr67Stang

I'm sure you have some servos in a box to pick from. The main thing I hear from the lil foamy flyers is the HS-55 strip when thay have one of those tail first landings. I think they are all using the carbonite gear servos now. But what the heck, build it to fly... not crash

flyinrog

My Feedback: (1)

Reminds me abit of Jeremy's half-wit...he did use a spar to strengthed the fuse, made from a carbon arrow shaft...Rog

paulsen

My Feedback: (2)

Dang combat you don't mess around at all!!! IMO if you want to use hs-55's on the rud/ele you should give your control surfaces pretty good size "counter balances" so the loads on the servos would not be to much for them. If you plan on going with out counter balances you may want to consider hs-65's or at least hs-56 karbonite geared servos on the rud/ele. I'm sure that if you stay below 16oz hs-55's will do the job on the ailerons provided you use one on each wing half.

I bring this up because I noticed the rudder does not look like it's gonna have a counter balance. Have you put a Norvel .074 on the Thrust-o-meter? I wonder what kind of thrust that little sucker puts out.

I love it already! Sweet looking little profile.

What is the wing span?

combatpigg

My Feedback: (3)

It is never too late to counter balance the rudder, I'll go ahead and do that. I have not tried the HS 56s yet. The HS 65s are pretty heavy, but so far have worked flawless. The .074 will get hooked up to the thrust-o-meter to get a target weight goal for this plane as well as help develope that perfect 3D prop. This is a side of the hobby that is just so interesting, this is modeling. I think half the fun about these projects is the uncertainty of the outcome. It was inspiring [and reassuring] to see that YETI 33.

This wing is 32 inches long and will get ailerons with about a 2 inch chord. The wing is 1 inch thick at the root and 1/2 inch thick at the tips, the spars are 1/8x1/8 spruce. The root chord is about 7.5" and the tips will be about 5". I will do just enough sheeting in the center to support the RX and battery, probably with 1/64 plywood. I figure that pull/pull control will work for the R/E and will station a HS 55 next to each wing flap. I'm still undecided about a fuel tank.

rainedave

My Feedback: (1)

This is the current thread to watch. And, Servo City is having a 20% off sale on HS-56's for $19.99:

http://www.servocity.com/html/hs-56hb_sub-micro.html

SST

My Feedback: (2)

Try a Diamond D-60 instead...Much stronger geartrain, and lots more torque in the same space.

paulsen

My Feedback: (2)

Have you already desided what your going to use for Rx power supply?

eroc144

My Feedback: (1)

Personally I love the HS65s. They're nearly the same weight as the HS56s and have got 25oz/in of torque vs 15oz/in for the 56s. They're a little more expensive but I have yet to strip any teeth on a 65, whereas my pile of gap-toothed 55s continues to grow...

EG

Sneasle

Is there a gear upgrade for the 55 available? i know you can swap over to the MG for the 81, but are like, the 56 or 65 gears interchangeable with the 55's?

combatpigg

My Feedback: (3)

Paulsen, I have five 150 mah nimh packs made up, and I'll make up some of those DC to DC lipo packs also. I just compared the 65s to the 56s and the 65s are a much better deal. The 56s have built in side mount lugs for laying down flat in a wing. I think the carbonite gears are worth the extra money. The HS 81s and 55s were a big improvement over the old S 133s, but I think it is time to move on.

rainedave

My Feedback: (1)

I'm going to try those HS-65s myself. I didn't realize they have ball bearings and karbonite gears and weigh less than the 81s, too. They look impressive.

beenie

My Feedback: (9)

I tried this several years ago with a scaled down and slightly modified Taco. I think I called it the Taquito. I never hooked it up to the thrust meter but the plane weighed around 17 ozs and would accelerate smartly out of a hover. Was not all that good in the 3D department but would do great wild manuvers. Used 4 HS81's and a really small one on throttle. You could cut a lot of that weight with lighter servos. Was a nice fun little plane.
Ben

combatpigg

My Feedback: (3)

beenie, that's a great looking plane! If a .074 can power 17 ozs out of a hover, that is encouraging. Thanks for showing your plane, I really like the trim and the colors. If you see a copycat version done here, please just consider it flattery [I'm not worth suing, anyway ].

matchlessaero

Pig, the .074 is what I eventually settled on for the best power for my Edgeling. Fun little setup. My personal suggestion would be to try to keep it under 15ozs. My 14 oz Edgeling with the .074 kicked butt. Great performance on that motor.

combatpigg

My Feedback: (3)

Matchless, 14 ozs will be the target weight then. I hope it will get there with four HS 65s and a P/Fer servo on throttle. It will be interesting to measure .074 thrust and to see if the APC 7x3 can be improved on. That was a nice article about you in Model Aviation with Billy H! I get a kick out of reading about his humble 3D beginnings with that ugly as sin garage sale plane. It's funny how a plane like that can transform into the most beautiful thing when you're having fun with it.

I think this plane will end up similar to yours in size and weight. I was leafing through my tattered plan archives looking for the original Morris Su-do-koi, [to scale down] but struck out. This one ended up looking kind of like a 3D FW 190.

I had almost forgotten how quickly a pile of sticks can turn shape into something. The elevator / stab are what is left to frame up. I'll use 3/16x3/16 sticks with the C/F treatment. I think the strands will do the most good on top and bottom after the framing is done, but will leave a lumpy and ugly mess to cover over.

paulsen

My Feedback: (2)

Your profile look's like it could turn out to be a "combo type" plane and fly pattern/3D like an OMP fusion. All of these 3/4 A profile's look beautifull!!!!!

Larry Driskill

Pigg, good mornin',

I have sometimes been able to get C/F tow to lay flat by either attaching it with med. CA and the rubbing it down until set thru a layer of wax paper, or, if the receiving piece allows, compressing and clamping the C/F is place under waxed paper and a stiff piece of backing wood.

combatpigg

My Feedback: (3)

I'll give that a try, Larry. Anything is better than having to sand that stuff. As it stands now the fuselage is still too rubbery to support the tail group. This plane is going to have a mind of its' own while flying if it isn't stiffened up. I did a mock up weigh in with all the major components [except for linkages and rigging] and it weighs 10 ozs, so some more weight could be invested in bulking up the fuselage. At this point, the best way I know of to eliminate twist would be to sheet both sides of the fuselage, but I know that other builders have gotten away with skipping that. Maybe that transparent monokote is stiff enough to do the job?

Paulsen, hopefully the plane will show its' beauty in the air . If it turns out too graceful [like a pattern plane], the outer 4 inches of each wing panel can be snipped off so the plane can be flown in a more undignified manner.

MJD

My Feedback: (1)

The best way I know to make a stiff open profile fuselage, is to use diagonal formers, i.e. Warren truss type construction, and put thin CF on those and on the sides of the longerons touching the ends of the CF strips on the truss. This is versus top and bottom of the longerons. This is more often done with CF unidirectional laminate versus tow - it is way easier to work with but you do need to lightly sand off any residual release. As an example I have a Ukraine made 2m glider whose horizontal stab is framed up truss style, of contest grade 3mm balsa with thin CF capstrips, and spanwise CF strips top and bottom of the TE and LE as well. You would snap the stab before you get much twist in it, the torsional rigididty is so high. And it weighs bugger all.

Wish I was at home, I'd snap a couple of digital pics of the stab, it's a work of art. The whole aircraft is actually.

When I put CF tow down I cut excess length, lay it on wax paper, then brush laminating epoxy into it. I then lift up the ends with an Xacto then lay it down (the hard part is avoiding any twist), trim, and really gently smooth it down with a flat sable brush dipped in the epoxy and cleaned off on a scrap of something. Seems to work but there may be classier methods. Naturally you need some MEk or the like around to avoid buying brushed all the time..

Cool project, although hardly a candidate for your piped CZ.. and still no 7-2 props. Last time I talked to APC they'll do the tooling for free, if you buy 5000 props at list price. All the electric props have higher pitch with the exception of the slow flier props which are most definitely no good, although a few folks do run the regular electric props on small glow engines.

MJD

combatpigg

My Feedback: (3)

Hi MJD, ya, if you could post a shot of that glider, then I won't have to buy it just to see how they go about their business I saw some of that C/F strip at the LHS, a little bit sure could go a long way. If 4 pound balsa sheet really was available, a lot of these gyrations would be unnecessary. I looked through the E props and 3.8 was about as low as they go, I guess the rpm of the electric motor and gear train dictates that. Those props are pretty scary looking anyway, I think a .074 could rip one up.