rv7driver

My Feedback: (105)

Well after looking at Stangs 2 oz tank it got me thinking about throttle control, I know not much out there but saw towers offers that China made AP wasp 061R/C. I would appreciate any advice about this engine I know nothing about 1/2 engines except cox, the add said glow wrench not included, I not sure if that means if not avaliable or what I do have a couple Norvel 074 but I think that would be way to much.

thanks ahead of time, Pete

Mr67Stang

Well here is a video of one of those .061 AP Wasp engines pulling 18 oz of airplane around with a 6x3 prop.
http://www.youtube.com/watch?v=eq2iMhRXbvI
They look almost exactly like a Norvel .061. as for the .074 being too much... Yes I think your right. Send it to me and I will save you from having to do it

rainedave

My Feedback: (1)

Yes, the .074 is way too much for this airframe. It was not designed for that size engine.

I own two Wasps and I like them. There are a few threads on them you can search for here in the 1/2A forum. It's an easy to start, reliable engine.

rv7driver

My Feedback: (105)

Stang,David thanks for the info on the wasp guess I'll order one, but it will go on another sure shark, you are going to make another sure shark run ,right david?????????? hope so. Stang nice video!!!!!! PM me I got 2 NIB norvel 074 maybe we can work something out

Pete back to work on the wing!

rainedave

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Building this thing a second time, I'm realizing that there's a lot more "free flight" in the SS's blood than, say, a .15 tor .25 size r/c design has. What I mean by that is the various components of the airframe may not seem all that rigid by themselves. A lot of the strength and rigidity come from the parts acting together (the stiffness of the fin once it's in the fuselage slot, for example) and the strength that the covering adds (the wing). With a model this size, powered with an .049, there's no need for each component to be really strong by itself. That only adds unnecessary weight. When everything is all together and covered each part becomes a lot more rigid. I didn't really do that intentionally; I think having built lots of 1/2A free flight models has made this kind of construction a subconscious thing with me. Anyway, if you want to add shear webbing and use spruce spars, by all means, go ahead. Powered with a Cox Reedy I haven't found it necessary.

I've gotten the covering done and I just need to decide how I want to add some color to the fuselage. That dark blue looks a lot more blue in the sunlight. It looks a bit gray in these photos.

Andrew

David --

What covering did you use?

BTW, I think the gray looks pretty nice.

fritzke

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I agree, thumbs up on grey, and also I love the simple spine/turtledeck
top on the fuse. Which plane did Joe Bridi use that on? It's a great idea.
Dave

rainedave

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Thanks, y'all. The blue/gray is growing on me. I still need to add a stripe or something down the side. The 3/16" top slab is something Bridi used (don't know who pioneered it). The cap strip/spine is just something I came up with, but I'm sure it's been used before.

I used Worldtex iron-on fabric from Horizon. From what I've read it's the exact same stuff as Solartex. It does say "Made in England" on the label, so I guess it is. This is the first time I've tried painting it with dope. It really worked well. You can still see a little bit of the weave through the dope so it definitely has that silk look.

The wing is covered with what they call Transparent Natural. It has a white color to it and is actually more translucent than transparent. It's also noticeably lighter and thinner than their opaque colors.

I'm thinking it would be great to cover an entire model with it and then paint it. It would be a lot faster and easier than filling the grain, priming, sanding, priming, filling and sanding again, like I did with the fuselage. Because it's fabric it goes around curves great and air escapes through the weave so you don't get bubbles.

My cheap postal scale says 5oz. with the ailerons and elevators hinged in place. I just put two HS-55s, a Berg rx, 370mah NiMH, 1oz tank and a Sure Start on the scale: just under 4oz. This thing can feasibly come in around 9ozs. That's better than I anticipated. A prop and fuel will add a bit more.

When I mentioned in another thread that I build in a 5 1/2 x 6 1/2 ft space I wasn't kidding.

rv7driver

My Feedback: (105)

David thats looks great!! mine has slowed down due to family stuff but tonight hope to finish the framing. I'm sending you a PM

PS got some of that glazing putty at NAPA, was surprised it is dark gray but it works great,thanks for turning me on to it!

Pete

hfenn

I agree Dave. I've always believed most R/C planes were over built, especially kits. Light flies best. If built strong (heavy) enough to crash- it will.

brocja01

Evening Guys.

Well right before I turn in for the night, I wanted to give a kudos to Dave for putting together such a nice kit. I'm still very new to the hobby, going on 2.5 years and I'm even newer to building (have only built the DNU and assembled two ARFs). And I have to say that this kit is going together very well. I have both wing halves framed up and glued together in 2 hours.

I'm really enjoying this build over the DNU simply for the laser cut parts. I don't have the skill (yet) to trace and then cut straight enough to make my build piece together as well as this build it. My DNU turned out ok, but it was a bear trying to get everything to line up when putting together the wing and such.

Well, I better go and see if I can get this CA off of my hands and hop into bed, 5:30 a.m. comes darn early!

P.S. I'll make sure to post some pictures tomorrow night

P.S.S. How do you guys cut the slit out for the aleron servo once the wing is epoxy'd together (assuming you use epoxy). I would assume that would be very difficult to cut through. Do you cut the slits out 1st then glue the wing halves together?
The only other wing I've ever built was for the DNU and that was a one piece wing with no dihedral.

rainedave

My Feedback: (1)

Thanks, hfenn. I think one reason is that kit manufacturers have no idea what engines people will shoehorn into their planes. They may feel that they have to stress .40 size models to survive being flown with Saito 1.10s. And today, people are actually doing that sort of thing. I'm almost certain that a TD .09 in a Sure Shark would fold the wings. But, I'm not going to engineer it or build one to prevent that from happening because it's an .049 - .061 design.

And I agree, light always flies better. The one I'm finishing now will be under 9.5ozs., probably closer to 9.25ozs. (I hold this up as proof that a dope finish can be one of the lightest of all)

I'm test fitting an AME .061 (thanks rog) in the nose. I had to raise the thrust line a bit so that I wouldn't have to cut into the right cowl cheek. Anyone know any reason why the muffler can't be put on backwards? On this engine it will still clear the prop disk and will give me more clearance between the cowl.

Mr67Stang

Well as I indicated earlier, I went ahead and cut the cheeks down. Still looks nice to me. I will get some pics out Thursday afternoon of the nose and the Aileron torque rods. I played with the idea of eliminating the torque rods and using a cable system run in the wing to operate the ailerons but decided if I get any good speed out of this plane I could not afford cable flex. I really need to learn the art of building light. I feel I am going to be coming in fat. I will see. To bad that hump back looks so good. I would eliminate it for weight but then it would not be a Sure Shark... can't have that

Mr67Stang

I used a dremel. I have not put the two 2 inch trailing edge peices on yet so I can get you pictures. (I'm at work now sot tommorow afternoon) But I used my dremel and cut out a 1/2 of the brass tube size trough in the trailing edge stock and the trailing edge spar so it would mate up centered. I did use epoxy to mate my wing halves.

Just re read what your talking about. I epoxied my wing halves together but have not put the top sheeting on the wing yet. I am cutting awaay to make my aileron servo fit then I will cut the sheeting to fit the wing and my servo before applying the sheeting. Still working out the orientation I want to mount my servo.

rainedave

My Feedback: (1)

brocja01, on the first SS I mounted the aileron servo offset to the side of the wing center. It changes the pushrod geometry a little bit, but not enough to notice in the air.

On this one I put it in the center. Cutting the notches in the two center ribs before joining the wings is the easiest way. Like Mr67Stang said, you can do it afterward, too, it's just a bit more work.

Mr67Stang, I would put the output shaft to the back, assuming that's what you mean by orientation. This will give a little more room for the elevator servo up front as shown on the plans. Or are you putting the elevator servo closer to former #2?

Mr67Stang

I currently have my control rods cut to lenths that I can put the servos (throttle/elevator) almost anywhere. Once I am all frammed up I will move things about for basic precovered ballance and determin actual locations. Remember that I filled the forward compartment with a 2 oz tank so my battery will have to go aft[:@] unless I want to go out and buy another flat pack I might be able to squeeze it in behind the tank. I might just take the fuse into the LHS and test fit some batteries.

rainedave

My Feedback: (1)

Scroll down until you see "Radical RC 370mah NiMH 4-2/3 AAA Cell 4.8V Flat RX Pack"

These are great 1/2A packs and weight 1oz.

http://radicalrc.secure-mall.com/sho...ia=&searchCat=

brocja01

And you guys are using the aleron stock trick by cutting your center joining stick out of aleron stock and then using that to get your dihedral into the wing?

hfenn

I've run the Norvel mufflers backwards with no problem. As long as the muffler exit clears the prop it'll work fine.

rainedave

My Feedback: (1)

The AME is going in the first SS. A brand new, custom fitted Skyline is destined for this one! It's the perfect match.

rv7driver

My Feedback: (105)

I just got an email from Tim said my skyline stage 3 would be finished today and I should have it friday or saturday. I'll put the skyline in this one.
/
David are you bringing the fuel line through the firewall for the skyline? I have the Sure Shark framed up working on the radio install, hope to have it finished when the engine arrives will post pic's of the completed plane soon!! I'm really fired up about this plane.

Pete

rainedave

My Feedback: (1)

Good news, Pete! Can't wait to see pics. Yes, I think I'll just run the tubing through the firewall.

Mr67Stang and brocja01, how are yours coming along?

Speaking of Skylines... Got mine today! This thing is truly beautiful. There are several subtle refinements that are very tastefully done, like the way the bottom of the cylinder is turned down and tapers into the case. Nice touch, Tim!

Withing minutes of opening the package I had it mounted on a test stand. I opened the needle valve 3 1/2 turns and put a drop of fuel in the exhaust slits. One bump of the starter and it was running. I can't recall ever having a brand new Cox engine fire up instantly on the first try. I let about 2ozs run through it at a rough 2-cycle setting. The second start was the same. One bump of the starter. I used up the second 2oz tank by momentarily pinching the fuel line about every ten seconds to lean it out and then letting it settle back into the richer state.

I break all my larger non-ringed engines in this way and I also think it's a good way to break in Cox engines. After a tank or two of these quick, momentary leanings an engine is usually ready to have the needle gradually turned in. I'll lean it a bit and still continue to pinch the line every once in a while. Lean it a bit more and continue the pinch test. It's the best way to know how lean your setting is. If the engine speeds up when you pinch the line it isn't peaked out yet. If the engine sags when you pinch the line it's leaned a bit too far. If you hear no change it's peaked and should be backed off a small amount. When the engine will hold this setting, slightly rich of peak, I consider it ready to fly. I like this break-in method because it's easy and there's no guesswork involved. You simply listen to what the engine is doing.

rv7driver

My Feedback: (105)

[:-]David, that is one sweeeet looking engine, and most of all thanks for the info on breaking in the skyline will follow it to a T.

David did you just leave the vent line open when you ran it? makes sense that you did or am I missing something? well back to it, radio done now sand, sand and sand some more and paint and cover. also what prop did you use for break in ,is it the same one that Tim sends?


Pete

Mr67Stang

Very nice looking engine. My SS project got put on hold all week due to other CR@P getting in the way... Okay one wasn't so bad. My 13 yr old daughter expressed interest in flying and we got her a Great Planes Piper Cub electric I think it would be awsome with a .049 after she gets the hang of flying it. 14 oz plane.

rainedave

My Feedback: (1)

Father of the year award?

Here's a shot of the tank compartment: 370mah NiNH, 1oz Sullivan round tank and Berk 4L Microstamp. Tight fit, but still enough room for some foam padding. With the battery in that location the plane balances right on the back edge of the main spar. Just what I want for the first flight.

Man, that Skyline looks nice.