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Nitromodels Katana 50cc build thread

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Old 10-27-2008, 09:04 PM
  #26
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Default RE: Nitromodels Katana 50cc build thread

Tonight I finished the throttle servo hookup. I replaced the Futaba 3004 with a Spektrum DS821. That was a good decision, because the carb is spring loaded and I'm sure the Futaba 3004 (a 40oz servo) would have constantly had to fight it (and drain the battery), but the DS821 (70oz torque) is so strong that it didn't even have to draw power to hold the throttle in place. So even when I turn off the receiver, the throttle spring is not strong enough to pull the servo arm. One worry less!

I was going to start to put the gas tank together, but I realized that the screw for the stopper is missing. :-( Cheap Chinese, I guess. I'll have to find a screw (from other gas tanks that I got lying around), or buy a stopper assembly, or buy a fuel tank. We'll see.
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Old 10-28-2008, 12:43 PM
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Default RE: Nitromodels Katana 50cc build thread

I'm building the same plane. (my first giant scale). Im anxious to see how your turns out and flys. Keep us posted.
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Old 10-28-2008, 03:26 PM
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Default RE: Nitromodels Katana 50cc build thread


Quote:
ORIGINAL: cpreinfalk

Tonight I finished the throttle servo hookup. I replaced the Futaba 3004 with a Spektrum DS821. That was a good decision, because the carb is spring loaded and I'm sure the Futaba 3004 (a 40oz servo) would have constantly had to fight it (and drain the battery), but the DS821 (70oz torque) is so strong that it didn't even have to draw power to hold the throttle in place. So even when I turn off the receiver, the throttle spring is not strong enough to pull the servo arm. One worry less!
You are supposed to unhook the sping clip so that the spring no longer exerts tension on the throttle. The same is true for the choke as well.

Do not remove the spring though, just unhook the side that engages the throttle or choke plate, so it no longer has any effect what-so-ever.
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Old 10-28-2008, 04:02 PM
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Default RE: Nitromodels Katana 50cc build thread


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ORIGINAL: opjose

You are supposed to unhook the sping clip so that the spring no longer exerts tension on the throttle. The same is true for the choke as well.

Do not remove the spring though, just unhook the side that engages the throttle or choke plate, so it no longer has any effect what-so-ever.
Hmmm ... I'll look into that. Thanks for the tip!
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Old 10-28-2008, 04:07 PM
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ORIGINAL: RCA8

I'm building the same plane. (my first giant scale). Im anxious to see how your turns out and flys. Keep us posted.
Where are you on yours? Feel free to let me know how you are doing with yours! I was hoping that somebody with the same plane can share their experience in this thread. What engine are you putting in? What servos? What do you do about the rudder? Are you putting in 2 servos in the tail for the rudder or are you doing a pull pull? Is your fuel tank complete or is the screw for the stopper missing (like on mine)? I ordered a Great Planes 24oz fuel tank (for gas engines) on Tower Hobby, because I figured I might as well.

What batteries are you putting in yours? When do you plan on flying it?

So many questions ....
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Old 10-29-2008, 06:09 AM
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Default RE: Nitromodels Katana 50cc build thread

Last night I put the rudder control horns in place and also the rudder servo. Since the plane is not "intended" for pull pull, I had to find a way to put the servo in. I found a good spot in the "floor board", where I just had to put in some pieces of wood as shims (epoxy'd them in place) and screwed the servo in.

Here's what's left to do/install:

- Cut out the spinner (right now the prop blades are touching it)
- Replace main wheels (I want to put in proper axles and wheels)
- Gas tank
- Install cowl (and make the vent cutout on the bottom bigger)
- Install ignition box
- Glitch box
- Ignition switch
- Receiver switch
- Servo switch
- Buy gas
- Install pull pull
- Extend holes for Canopy bolts (they don't line up (cheap Chinese))
- Test fit right wing and extend the holes if necessary (did that for the left wing already)
- Fuel DOT (not necessary for first flight)
- Tighten covering

So that's 15 items, I should be able to knock out a good number of it on the weekend and one or two during the week every night. Everything considered, I think I'm going to maiden it in a week and a half (the weekend of 11/8). I'm not rushing it, though, because on this plane I wouldn't feel comfortable if I took any short cuts.

BTW: I bought one of those fueling systems on Aero Works. The one with the manual crank for $70. If I had bought the parts separately, it would have been cheaper, but this way it's nicely and neatly put together for me. I already have the Lawn Boy 2 stroke oil (Home Depot), because I heard that for break in you're supposed to use non-synthetic oil, as with synthetic oil the engine actually won't break in right (or at all?)
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Old 10-29-2008, 08:07 AM
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Default RE: Nitromodels Katana 50cc build thread

im using a jr 8611a servo on the rudder, 8411's for the elevator, and hi tec hs 985mg's for the ailerons. i bought an ftl 52cc from hobbycity.($175) i bench mounted the motor and ran it. it seems to run great. i cant believe it for that price, but i think its going to be fine. ive read some reviews on it and most looks pretty positive. i have the servos mounted and thats about it. how far is your prop nut from the firewall? it looks like i'll only have to shim about 5/8". when I mount the engine. my local experts also tell me to unhook the springs on the throttle. i think the plane is well worth the money. im going to use 6 volt ni mh batteries for the reciever, so i wont have to us a voltage regulator. redundant batteries in case one fails. they both need to be the same voltage and mh. just plug the other one into a vacant slot on the reciever. then ill use a 4.8 volt battery for the ignition.
1500 mh or so. our local battery outfitter will make up the battery packs. i just buy the aa batteries and solder them up. that will save some bucks. good luck with the build im really anxious to know how yours flys. how much down thrust did you put on your motor? instructions with the kit are pretty worthless.
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Old 10-30-2008, 05:54 AM
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Default RE: Nitromodels Katana 50cc build thread

Honestly, I didn't put any down thrust in it. I saw that the firewall has built in right thrust and then I didn't bother anymore trying to change the thrust myself.

Yesterday I shrunk the covering a bit to get rid of the wrinkles and to tighten it up for more structural rigidity. I also started with the pull pull. Connected the wires to the rudder (both sides), ran them through the fuse. Tonight I need to connect the wires to the servo.
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Old 10-31-2008, 06:01 AM
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Default RE: Nitromodels Katana 50cc build thread

Last night I finished the rudder pull pull (finally). I then put in the receiver and connected the glitchbox to the receiver servo connections.
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Old 11-01-2008, 12:30 PM
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Default RE: Nitromodels Katana 50cc build thread

Is this the same plane that FlyRC just did an article on? The one that they pictured had a blue canopy which didn't look very good. The covering looks the same, but there seems to be some other differences too. They mentioned gluing in the vert and horz stab, but that doesn't seem to apply to yours.

Does the wing slide forward and aft in this one to help set the CG? I can't tell from the pics.

Also, does it use CA hinges? They mentioned that in the article, but they seem marginal on a plane this size. How has the hardwae been in general?

Lastly, did the motor box end up having off-thrust built into it? You mentioned that it didn't, but it looked like you just used four stand-offs of the same length to mount the motor.

Sorry for all of the questions. I'm trying to decide whether of not I should get this one. It looks good for the price and looks like a bigger version of my Ultra RC Katana X which is a sweet flying plane. I only have a Brison 2.4 though, so I need to see what you get for an AUW to see if it will be adequate.

Good luck on the maiden!
Greg
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Old 11-01-2008, 05:37 PM
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Default RE: Nitromodels Katana 50cc build thread

Can someone please measure from the firewall to the spinner backplate. I also am thinking of getting one and would like to fit a DL50. If the firewall is too far close then it won't fit with the stand offs. I have thought about cutting the hole in the firewall larger to fit the carby through but i am concerned about fuel blowback getting into the fuse. Thanks
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Old 11-01-2008, 07:48 PM
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Default RE: Nitromodels Katana 50cc build thread


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ORIGINAL: G.P.

Is this the same plane that FlyRC just did an article on? The one that they pictured had a blue canopy which didn't look very good. The covering looks the same, but there seems to be some other differences too. They mentioned gluing in the vert and horz stab, but that doesn't seem to apply to yours.

Does the wing slide forward and aft in this one to help set the CG? I can't tell from the pics.

Also, does it use CA hinges? They mentioned that in the article, but they seem marginal on a plane this size. How has the hardwae been in general?

Lastly, did the motor box end up having off-thrust built into it? You mentioned that it didn't, but it looked like you just used four stand-offs of the same length to mount the motor.

Sorry for all of the questions. I'm trying to decide whether of not I should get this one. It looks good for the price and looks like a bigger version of my Ultra RC Katana X which is a sweet flying plane. I only have a Brison 2.4 though, so I need to see what you get for an AUW to see if it will be adequate.

Good luck on the maiden!
Greg
Well, the plane that I ordered is a Nitromodels Katana 50cc, and FlyRC reviewed that one, but somehow mine is a bit different. You pointed out the differences and you are exactly right:

- The canopy is not blue
- The wings can't be moved fore and aft
- It has proper pin hinges and not CA hinges
- Vert stab is part of the fuse and didn't need to be glued in
- Horizontal stabs are mounted with an aluminum tube and bolts

So all in all, it's better than the one that FlyRC received, except for the fact that the wing can't be moved fore and aft. Also, the color looks better than on the photos of FlyRC and the photos on the nitroplanes website.

The box DOES have right thrust built in. To be honest, I didn't check if it has down thrust built in. I'll see how it behaves when I fly it and will fix it if necessary.

The hardware is good and bad. I had to buy another fuel tank (well, the stopper didn't come with the screw and then I figured I might as well buy a hole new unit), I will replace the wheel axles and I bought a pull pull because I don't like the dual servo rudder setup. The hinges, metal clevises and the ball links are definitely good rate and I'm using them.
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Old 11-02-2008, 02:34 AM
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Default RE: Nitromodels Katana 50cc build thread

Thank you for the info, that sounds really promising! I really do like the looks of yours better than the one in FlyRC and would get it in a heartbeat if I could trust the AUW on the website. Kind of hard to trust them when all of the other info and pictures seems to be wrong though!!! Any chance that you happened to get an empty airframe weight before you started the build?

Thanks again,
Greg
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Old 11-02-2008, 05:43 AM
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Default RE: Nitromodels Katana 50cc build thread


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ORIGINAL: bobbee0155

Can someone please measure from the firewall to the spinner backplate. I also am thinking of getting one and would like to fit a DL50. If the firewall is too far close then it won't fit with the stand offs. I have thought about cutting the hole in the firewall larger to fit the carby through but i am concerned about fuel blowback getting into the fuse. Thanks
I'll measure that today and will let you know.
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Old 11-02-2008, 05:46 AM
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Default RE: Nitromodels Katana 50cc build thread

No, I didn't weigh it before I started.

What does "AUW" mean?

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Old 11-02-2008, 06:17 AM
  #41
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Default RE: Nitromodels Katana 50cc build thread

All up weight.
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Old 11-02-2008, 10:16 AM
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Default RE: Nitromodels Katana 50cc build thread


Quote:
ORIGINAL: cpreinfalk


Quote:
ORIGINAL: bobbee0155

Can someone please measure from the firewall to the spinner backplate. I also am thinking of getting one and would like to fit a DL50. If the firewall is too far close then it won't fit with the stand offs. I have thought about cutting the hole in the firewall larger to fit the carby through but i am concerned about fuel blowback getting into the fuse. Thanks
I'll measure that today and will let you know.
It's 6 inches.
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Old 11-02-2008, 10:23 AM
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Default RE: Nitromodels Katana 50cc build thread

I'm making good progress. I installed the new (4" rubber Dubro) wheels, fitted the canopy bolts (had to drill the hole on the left to make it fit), finished the installation of the gas tank, bought 2 gallons of gas and mixed 10 oz of Lawn Boy oil (non synthetic for brake-in) for a 1/25 ratio, put in the receiver and the glitch/power box, installed the receiver switch and charging jack.

Here's what's left to do:

- Cowl (make vent bigger, install)
- Ignition switch (on order)
- Servo switch
- Right wing bolts
- Fuel DOT (don't need that before maiden, though)
- Strengthen fuselage (meaning: put some epoxy in places where I don't get a warm and fuzzy feeling)
- Secure servo extension connections (ordered some of those connection safety thingies)
- Check the CG and secure the batteries accordingly
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Old 11-02-2008, 01:58 PM
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Default RE: Nitromodels Katana 50cc build thread

Awsome! Can't wait to hear how it goes!
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Old 11-02-2008, 06:38 PM
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Default RE: Nitromodels Katana 50cc build thread

Thanks
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Old 11-03-2008, 11:20 AM
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Default RE: Nitromodels Katana 50cc build thread

After drilling the holes for the cowl I saw the confirmation of what I was afraid of: I have to move the engine (sigh!) a bit up and a bit left. The spinner doesn't line up too nicely. Wouldn't be a problem for the maiden, but I just doesn't look good and the thrust line will be a bit off. It's the right thing to do and I won't wait until after the maiden. I just hate that hole mounting-the-engine task and now I have to do it again. At least I made a plywood mounting pattern. Now all I have to do is measure how much I'm off vertically and horizontally and then drill one hole and then line the remaining 3 holes by using the mounting pattern thing.

On that note, they included something nice in the hardware for the cowl installation: Additionally to the bolts and those nuts that "eat" into the wood to stay put (forgot the name of them), they also have these little rubber things that you stick in the holes of the cowl (they stay there) and they help with the vibrations so the holes don't get unintentionally widened by the bolt rubbing against the fiberglass of the cowl. I like it!

Yesterday I also went over the wings with hot air to tighten the covering.

Oh, and I made a hole in the covering of the fuselage with my drill (accidentally), so I'll have to patch the covering already, without even flying it once! Oh well.
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Old 11-04-2008, 09:02 AM
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Default RE: Nitromodels Katana 50cc build thread

I mounted my engine and then cut out the cowl for clearances. I have the same problem as you. My engine is
one inch too low to be centered in the cowl. I havent decided if Im going to raise the engine yet. I think I'll fly it first. I might see how it looks with the spinner on. possibly make and adapter to fit in the front of the cowl with new hole.
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Old 11-04-2008, 11:47 AM
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Default RE: Nitromodels Katana 50cc build thread

Last night I moved the engine up and to the left. Since my firewall looks like Swiss cheese with all the holes now, I used the plywood pattern I made earlier to double the firewall. Meaning: I put it behind the firewall to strengthen it.

So far I'm on track for a maiden flight this weekend.

To keep you all interested: I'll have somebody video the first few flights and I'll post them here (along with pictures). Don't know if I mentioned that already.
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Old 11-04-2008, 09:36 PM
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Default RE: Nitromodels Katana 50cc build thread

Tonight I got another few things done:

- Cut out the cowl some more to make it fit after moving the engine left and up
- Made the vent on the bottom of the cowl bigger (more exit air flow)
- Installed the ignition switch (it's an MPI switch with integrated charger jack)
- Put the wings, cowl and canopy on and checked the CG. With the servo and ignition batteries moved forward, the CG is about a bit less than an inch further back than recommended by the manual. I can live with that. My small planes all have the CG far back for 3D stuff, and I think that the CG range on a plane this big should be more than an inch, so I don't think it's too far back to be comfortably flyable

What's left to do:

- Install servo switch
- Fuel DOT (I decided to put it in before the maiden, because I already have it at home and it's nice to have)
- Secure the clevises (I'll do that with shrink tubes)
- Strengthen fuselage with epoxy (probably not necessary, but I'll put some epoxy in some spots just to make me feel better)
- Secure the servo extension connections (I already ordered those safety thingies for that; usually I use electrical tape, but on this one I want to do it nicer)
- Tie down the 3 batteries (I already know the locations, so that's going to be a snap)

It's all very much doable by this weekend!

Check out the pics. Note how narrow the car looks in comparison to the length of the plane ...
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Old 11-04-2008, 10:03 PM
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Default RE: Nitromodels Katana 50cc build thread

Looks awsome! I can't wait to hear what you think of it in the air. If it's not too much trouble can you please hold it on a bathroom scale to give us a rough idea of what it came out at for you? Please, please, please???

I emailed Raidentech a few days ago asking which version they are currently stocking (blue canopy or clear) and they never got back to me. From what I have read this is typical customer service for them. Kind of debating if I should put my money down or not.

Take care,
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