Patto

Greetings fellow R/C enthusiasts!

I'm starting this thread about the new Nitro Models Cessna 337 Skymaster. So far, I have not yet seen one completed and I have not yet seen a build-thread on one, so here it goes.

I ordered the airplane in the evening of May 2nd from www.nitroplanes.com and received it today, May 8th. It was shipped within 24 hours as far as I can tell. It arrived neatly packaged and undamaged. The pieces are all individually wrapped in plastic and there is a thin foam sheet between many of them. Each control surface is hinged except that the hinges are not yet glued, (CA type hinges). The cowls are fiberglass and are painted.

As I had heard, the vertical fins have no rudders built into them. I have not yet decided if I will perform some surgery and put them in before the maiden flight. I like to do hammerheads, spins, etc., so the idea of NOT having rudders just bothers me. If I had heard about that issue before I ordered the plane, (the website actually notes that two servos are needed for rudder) it may have made me hesitate to buy this one in particular.

The airfoil on the wings is a high-lift flat-bottom/trainer-style airfoil. This basically ruins my plans for low inverted passes, but I'll manage to get by.

I have 2 new GMS .47 engines that I planned on putting in it; however, I am looking at those long mufflers and they may not fit inside the cowls. Therefore, I may be sending them back and putting in an O.S. FL-70 that I already have on hand and a second .70 4-stroke that I have not yet ordered.

MORE TO COME... (and pictures, too, of course)

Patto

I've invested about 4.5 hours into the project, much of which I've spent planning the set-up, inspecting the parts, etc. So far, I have finished the main wing panels and I've started on the fuselage. I've installed the main gear and nose gear. I have also installed one of the fuel tanks with the other ready to set in place tomorrow when I continue.

I heard from a fellow RCU member who cut out the rudders about 2" into the vertical fins. His design looked very natural, as if it were how the manufacturer had sent the plane. I may go with a similar approach, or, perhaps easier, would be to just attach the rudders to the trailing edge of the vertical fins since they are not tapered. I've attached pics of the tail boom and fin.

I have decided, after carefully pondering mufflers, sounds, expense, etc., and I've ordered a Magnum .70 4-stroke as the second engine and I'm sending back the two GMS engines for a refund, (I never put any fuel in them or mounted them onto the plane). I thought about saving $10 and getting a second O.S. FL-70, but it really does lack in power compared to other engines. I know I won't be able to get them in sync, but since it's a push-pull config., it really shouldn't matter if they're off.

I'll do some more work tomorrow, hopefully, and post after I do.

If you have any comments, suggestions, or anything else, please feel free to post!!

TLH101

My Feedback: (90)

If the tank you show in the pics is the rear tank, you will need to turn it around, or find some way to get the clunk to stay at the back of the tank.
Would look better to cut the rudders from the fins and then hinge. Just adding on , will look, well, "added-on".

Robby

My Feedback: (18)

As Terry noted,, the rear tank is going to be a problem in the
current configuration...
Would be easy to just run a longer brass pipe for the clunk
line and the put a 180 radius bend in it so the clunk is to the
rear so it will always have fuel.. [8D]

Patto

You know, I knew ahead of time about the fuel tank set-up needing to be facing forward/away from the rear engine, and yet I installed it wrong anyway. I'm certainly glad I started this thread!! I will probably just turn the tank around entirely.

Terry also has a good point about the rudder add-on. However, there may be a way to make it look good if I can just make the shape/lines match and then put on matching covering. I don't know, yet, if I'll go through all the trouble, but it certainly is going to be an issue for me when I want to do hammerheads and spins and such... I asked on another thread if anyone had thought about mixing with the ailerons and flaps to simulate rudder control. I'm wondering if I can mix it so that when I apply, for example, right rudder, the right flap goes down and the ailerons input slightly to the right to keep from rolling. But, at slower speeds, with lots of power, this could have a very different, maybe even opposite direction sort of effect. I'm not worried about coordinating turns so much as I just don't want to get bored with loops and aileron rolls. I don't want to 3D in it, naturally, but I want to be able to do the basics, at least.

*sigh*

Okay, these pictures are from the other RCU member who did the modifications to his vertical fin:

TLH101

My Feedback: (90)

That looks like really good way to do the rudders. I just can't imagine flying a bird this size without rudder. And with the style of ailerons you have, you may need to coordinate with rudder in the turns to keep the tail from dropping. But I think you will also need it on take off to control the model, as it rotates, and the nose wheel leaves the ground. They will be worth any amount of time and trouble needed.
The model fuselage a lot better in the pics you posted than the ones on the website. I was really turned off by the website pics, because the model looks so "skinny". It looks much more "beefy" in your pics.

Patto

Yeah, I'm actually pretty impressed with the integrity of the structure itself. The covering job is decent, not great, but good enough. Obviously, one can expect wrinkles upon arrival, and that's easily remedied with a heat gun or hot iron. However, some of the lines are not the straightest. At least all the lines with the control surfaces match up so far, so that's a bonus.

I'm hoping I can do the rudder thing without having to re-cover the fins and rudder. I'd like to be able to make the cuts and then just apply some white monokote strips where it ends up needing some trim.

Patto

Did I mention yet that the instructions are very incomplete and mostly incomprehensible? I know, I know, it's loosely translated by some under-paid ESL student in China, but maybe they could try and get someone in the U.S. or U.K. to re-make the instruction booklets like these to make them more useable? Just a thought...

Spydermonkey

Hey thanks for the thread! If I had not been reading up on your build, I myself would have left the rear tank mounted 180 out! Good Idea about the brass tube. About the rudders, I found it not to bad to recover them, and you'll have to use 1/4in x 1in balsa to have the right mount of bite for the hinges. I found that w/o the covering it was easer to get my angles to cut the balsa. But hey there are always more than one way to skin a cat!

Patto

I ended up taking the tank out and I plan on just turning it around. I set up a long piece of brass on the inside of the tank and made a 180 bend and attached the fuel line and clunk. Then, I found that the clunk was getting tangled up in the brass tube and could end up getting stuck, leaving about 1/2 tank of fuel inaccessible to it. So, mine will just be turned around...

Patto

PROGRESS BEING MADE - about 8 1/2 hours total so far invested in project. I have mounted the rear engine and have begun mounting the front engine, which arrived in the mail today. The servos for the throttles and nose gear are mounted in the fuselage. I received two Hobbico mini servos for the rudder today. With the 6V battery I'm using, it is supposed to have around 53 oz. of torque, so that should be plenty for each wimpy little rudder.

Now, here's an issue that I'm seeing: The wings mount using two aluminum tubes per panel, but they have no retention screw set up! There are wing struts included that seem pretty durable, but since they are at a downward angle, they may allow the wing to slide a little bit on that tube.

I thought about just epoxying the tubes in place and making it a two-piece airplane, but that really is not convenient for transport at all!! I also thought about epoxying the tubes into the center wing panel and tail booms and then doing some surgery on the wing halves. I was thinking about putting a hardwood block on top of the tube route inside the wing and then having a screw go through the tube and into the block to hold the wing on laterally.

Anyone have experience with these plug-in style wings that could shed some light on this for me? Am I missing something? I've included a pic from Nitromodels showing how the wings plug in.

Patto

Rear cowl has been trimmed and front engine mounted. I'm playing around with the fuel tank locations a little bit to keep them from interfering with the throttle pushrods.

I suffered my first injury from this plane the other day while cutting a hinge slot in one of the rudders. I saw it coming, and I thought, "Oh, I'll just break the rule of 'Never cut toward yourself' this once and just for a second!" Now I have a nice, deep x-acto knife slice in my left hand...

So, I still really need some advice on what to do about the wing plug-in issue!

Spydermonkey

Hey P I just epoxyed my together, not to bad but trasport will be tough. I'm working on a pvc stand to allow the plane to sit securly in and will allow the wing tips to hang over the bed rails. Guess this idea wouldn't work if you don't have a truck. Brent

jrf

My Feedback: (551)

There may already be a hardpoint in the wing somewhere for a retaining screw. If there isn't, cut a small hole in the bottom of the wing, over the main tube, at the outboard side of the last rib the tube passes through. Glue a dowel or hardwood block into the hole and against the rib. Drill through the dowel/block, tube socket and tube, tap the wood and put in a socket head screw long enough to engage the tube. Epoxy the other end of the tube in place.

For easier transportation, I would glue the tubes into the outboard sections and screw them into the center section, but I can't tell from the photos whether the structure would allow that. You don't want to screw them into both sides because aligning them each time you assemble the airplane would be a b***h.

Jim

Patto

Spydermonkey,

I have a pick-up as well, and I actually had not thought about the possibility of the wingtips just hanging over the sides like that, it may work just fine!

Jrf,

I'm having a hard time imagining what the end product looks like, but it sounds perfect. Can you provide photos of a similar aircraft with that set-up or can you draw it?

jrf

My Feedback: (551)

Drawing attached. When you are done, all you will see is the screw head.

Jim

Patto

Excellent drawing!

As luck would have it, I found a piece of hardwood under the balsa about 1/4" from where the tube stops inside the outer wing panel. The cardboard tube sleeve goes through this hardwood block. So, using your idea, I will be installing a screw that goes from under the wing, through the block, through the tube, and then through the block on the other side, where it will fit snugly to stay in place during flight.

Should I be putting one in the smaller rear tube as well?

jrf

My Feedback: (551)

If the rear tube has a block like the front one, do it. Otherwise I don't think you need to.

Does it have a block in the center section also?

Jim

Patto

I did not check the center section for the blocks. Besides, I think I want to epoxy the tube inside the center section and tail booms to keep them together. I can't see any benefit to having the booms unattached to the center. In fact, I think they would be more likely to get damaged from travel and handling without something holding them in place at the leading ends.

I didn't have time to check for the blocks in the little/rear tubes, but I will check. I would certainly prefer to have 2 screws holding the panel on rather than one, just in case.

Patto

There ended up being two little holes drilled out under the covering on the main wing panel just in front of where the aluminum tubes end. Naturally, I was a little put off by this since the instructions have no pictures, no text, nothing indicating what to do and there is no hardware for attaching the wing. So, I'm either going to go with jrf's idea for install, along with the blocks already installed in the outer wing, or I'm going to epoxy the whole thing together and call it good. Here's a picture of where the holes are.

Patto

I have cut out the windows for the cabin and glued them in place using a flexible, clear plastic canopy glue that I bought at the local hobby shop, Eugene Toy & Hobby. I cut out the canopy but will wait to do the final fit on it until I have mounted the wing in place.

The engines are both installed. I'm debating whether I want them both on the same channel or if I want to use the channel 6 knob for the rear engine throttle control. The only issue I'm seeing with that is the throttle cut-off option.

I'm using so many Y-harnesses in this rig so far it's ridiculous!! I have installed 7 of the 11 servos, (9 standard, 2 micro) I will be using. I have a 6 volt, 2100 mah battery that I will be using for the receiver. I plan to charge it between flights. Anyone believe it won't be enough for all those servos?

clifford

Hi,
Just caught up with the thread, this kit looks very interesting, I"ve also looked at the bigger, KMP 337, but...when you look at the projected finished weight of the two models, this kit looks [at first glance]...as to have a lot lighter wing loading..??..ie...only 10" shorter in span...with a lot less AU weight at the end....good price too!!

Cliff

clifford

Forgot to ask..
.is that just red coloured, protective film over the windows and windscreen??

Cliff

Patto

Hi Cliff,

No, it's actually died an orange-red kind of color.

Just finished framing the "new" rudders. Next I will sand, re-cover, and hinge them. Then, I will be attaching the vertical fins to the tail booms and installing the horizontal stabilizer and hinging the elevator. After that comes installing the servos in the tail booms.

Currently, it is set up to take two servos for the elevators, one in each boom. Since I'm using two standard Futaba 3151 digital servos back there at 6V, I'm wondering if I can use one for the elevator and one for both rudders???

Spydermonkey

Hey P
Well it's nice to know that they did put screw holes in the wing for removal! to bad I didn't find them sooner You're right about all the y harnesses though, I've seen less of a mess on a plate of speghetti! hope the build is going good, I plan to fly mine this weekend! will let you know how it does! B