North Star project

[RedDwarfIV]

I recently bought a kit for the Balsa USA North Star seaplane. At the time I thought it was a Ready To Fly thing, but then I saw it said 'Plans'. I looked that up, and found that it meant it was a balsa kit you build from scratch. So I thought to myself "I've made R/C stuff before. I can probably reuse some of the parts. Why not?"

 

However, I have noticed that some of my parts won't work for it (IE, the 2-channel boat/car controller, and the reciever doesn't have nearly enough range) and I'm not sure about the rest. Some quick calculations told me that with the Kv rating of my motor, and the voltage of my LiPo cell, I'd get higher RPM (and higher torque) than a petrol engine. I may be naive, but i have trouble believing something so small could move a plane which I later discovered had a wingspan of over a metre.

 

 

Basically, I need some help working out what parts I can use, and what parts I need to get. Plus, I'm on a tight budget - I can't afford to spend

Edited May 29, 2014 by RedDwarfIV

[Smoothybb]

I'm not clued up on either the model or balsa in general and without knowing the exact model, hard to tell. Tamiya Cowboy probably the best person to try on here.

 

Looking at some other forums discussing a 45" 'northstar', I'd say you'll need lower kv motor, higher v lipo and esc plus some new servos. All of which won't actually set you back much if you go on the hobbyking website.

 

As for radio gear, personally I would stay away from the one you linked. It's a real basic radio, I bought something similar, used it once, never again. I went for real budget 6ch Flysky FS-T6 I think it's called. While it's nothing special, I've had no problems and range is as far as my eyes could see into the sky. It's about 10 quid more than the one you linked but it will have a lot more options and settings, being computerised. Rx's are only a tenner as well should you buy another plane or want to use it with the fanboat. My mate has the Turnigy 9x which is again, cheap but effective, probably above where you need to be though. Question is, are you going to expand your range of models and will you be getting more complicated (more channels)? No point in getting a 4ch or even 6ch if you see yourself needing more in the near future.

 

Your last question - if you mean why were you on 1/2 throttle using a car/land 27mhz controller when stick was centred? If so, it's because with flight there generally isn't a reverse so the stick being centred actually registers with the esc as half throttle. So yes, it sounds like the esc was for a plane and saw 'full reverse' on the controller as 0 throttle and anything above as requiring throttle. If that's not what you mean, ignore me!

[Tamiyacowboy]

depending on KIT size. 

 

the aircraft box will have a, scale size number, ie 1:72 etc etc. 

 

usually we will pop in sub 9gm servos, small and lightwieght.

props we tend to run 5"-6" slowfly props (apc prop is fine )

 

motors tend to be small so yours is about right ( possible overpower but nowt wrong there just less throttle needed)

25a esc is a bit beefy a 12a-15a would have done but thats all good.

Battery wise you may struggle, its a BEAST, you want smaller 7.4v with lower mah , it means a more lighter battery.

 

Throttle acting funny. it is because your using a midsticks throttle. in aircraft we have NO reverse, we have a max throttle and a min throttle.

a land tx is for cars so you have a small throttle band ( center stick to max), then you have center stick, ie no throttle, then you have back stick

and this is reverse. 

An aircraft stick will be low to max high, at middle stick you have 50% throttle. hence why your seeing motor have a 50% throttle even when you

go to midstick ( trigger middle on throttle).

 

here is what i would do, first off grab a nice thick BOARD.

grab some cork floor tiles and glue these to top of your board ( this forms your building board)

PIN your plan to the building board. now use modeling pins to make your aircraft.

lay your parts ontop of the plan and glue them up, use very very small amounts of glue DO NOT GO MAD.

Now as you build up the AIRFRAME you will see its size. how its put together and space you have to work with.

you need TWO servos ( RUDDER - ELEVATOR ) these fit to the tail sections of aircraft ( up and down - left and right )

a third channel is for the throttle ( up-down/left-right/throttle up-throttle down) the basic 3 channel setup.

 

WING : ........ 

 

a win produces lift, it may be only say 15 inches long but its surface area is key. adding it up the surface area would be alot more bigger

ie 1square meter for an instance. this is a large area. the whole wing produces lift so the larger surface area the bigger the lift/more lift.

the air needs to travel over the wing at a certain speed to produce lift ( a real plane like a piper cub around 60knots (40-60mph)

any less the craft will not produce lift. the propeller is to power you forwards keeping wind speed over wing to a safe level.

 

Build your model up , get used to how they are built and covered. 

 

4 channel is a good place to start, when your more into flying it will give you four controls

rudder - elevator - aerlions - throttle = 4 channel trainers

rudder - elevator - throttle = 3 channel learners

 

here is an image of the North star Basla built up but yet to be covered, its a huge model 

 

Edited May 30, 2014 by Tamiyacowboy

[RedDwarfIV]

I know I need at least a 4-channel because the standard North Star has ailerons, and I'd like mine to be capable of rolling.

 

I will definitely take in your suggestion for a controller.

[Tamiyacowboy]

after looking at the size, 

 

a 3s - 4s battery would be better. 7.4v is a bit lightweight  for this size of wing 

 

Glues, we can use a couple, 

The best glue would be ELMERS wood glue ( that white/yellow wood glue used in schools)

the second best glue but brittle is good old superglue. 

 

if you are unsure and its your very first time, maybe look at a smaller chuck glider model

less on the pocket, same style of building just more smaller and managable. 

rubber band powered are popular and can be fitted out with light weight RC gear to. 

 

Handset wise : Hobbyking do a 9 channel radio system for

[RedDwarfIV]

More powerful batteries, got it. Though since i've already bought the kit, buying another one doesn't help much. And I'm not really interested in flying a rubber-band glider.

 

I managed to find a Flysky 4-channel airplane/helicopter controller with 6-channel reciever on eBay which had been at

Edited May 30, 2014 by RedDwarfIV

[Tamiyacowboy]

aye take your time, it will take a while to build up the bird. 

 

4channel - 6channel is fine, the rubber band flyer is to help you learn building.

you can and will make mistakes so take time, 

 

few tools that are handy: 

 

sharp hobby knife for cutting,

some fine sandpaper/ and or wife-gf's nail file ( works wonders in small places)

a set square will help things be plumb and die. 

 

for your glue, have a tiny pot and put a small amount of glue in, use a fine paintbrush

to lay down a thin layer. Grease proof paper over the plan will help to stop parts sticking to it ( can be reused on other builds)

rubber bands make for some awesome holders, they can keep things inplace while glue sets up. 

 

major thing is never rush, slow and easy ....... it takes me around a week - two weeks to cut and glue up an airframe

 

feel free to pick our brains and ask any question however dumb/silly it may sound.

[RedDwarfIV]

Thanks.

 

I have a picture of my fanboat if you want to see it. It's a pretty ugly looking thing, but it was more an excercise in engineering than aesthetics. It does work, and despite repeated capsizings (the airplane throttle catches me out sometimes) all the parts are still operable. I learned my lesson after a bath-test resulted in my first ESC catching fire. I mentioned the servo being unsuited to re-use? That's because it's sticking through the lid of a watertight food container I bought at Tescos and is glued in place. The lid ends are held in place by one of the metal bands that holds on the 'outriggers' and a tiny glued-on metal bar that I bent into shape specially for it. It uses the plastic hull from one of my sister's toys, and the rudder sails are card covered in electrical tape.

 

I built this on my first Work Experience week. It was pretty fun.

Edited May 30, 2014 by RedDwarfIV

[Tamiyacowboy]

for your northstar build 

 

three standard size servos will be perfect. you can find these real cheap about on ebay and likes.

 

we have a boat section to, i run a jetboat, its like a jetski inside a boat.

very quick and nimble in the turns, they are popular over in the states and australia

drag racing jetboats , and jetboat racing around very shallow pond courses. 

 

and feel free to pick our brains, here at MSUK we try to give the best advice and help

if we have members close they will even offer to meet up and help/advise and even setup rc models

for those with less experiance. 

 

over in this website forum, they have a huge following and also some have converted from nitro engines to electric.

well worth reading and searching for tips and building your northstar 

 

http://www.rcgroups.com/aircraft-electric-airplanes-4/?s=ac8e4f5b8e425bdbf403a4fdb3153f55&

Edited May 30, 2014 by Tamiyacowboy

[RedDwarfIV]

I was reading a lot of threads on RCGroups after I bought the kit, and it was really informative. I'll have another look to see what sort of motors they're using.

 

I came here though because it's a forum for the UK, so you'd know things like which controller mode to use or which frequencies are illegal over here or things like that.

 

 

[Edit]

 

I decided it might be a good idea, if only so it'll be easier to see it, to put lights on it.

 

 

The landing and navigation lights will need to be waterproofed, I think.

 

[Edit The Second]

 

Finished the side-view.

 

The tail art, if it wasn't obvious, shows a compass pointing towards a star.

Edited June 1, 2014 by RedDwarfIV

[RedDwarfIV]

For some reason my iP LiPo Flight Pack 2100mAh 2-cell battery won't charge anymore. I was going to get a new battery anyway since the current one is puffed up and not powerful enough for the North Star model, but now I have to get it soon.

 

[EDIT]

 

Turns out I misread the damaged label on the motor. It's actually rated at 8-12 volts, and so will work with the Overlander Supersport battery I plan to buy to replace the iP Flight Pack.

Edited June 4, 2014 by RedDwarfIV

[RedDwarfIV]

Sigh. Change of plan.

 

I simply cannot find a motor that is equivalent to a .45 4-stroke engine that is within my budget. The more powerful it needs to be, the more expensive the motor, ESC and batteries get.

 

So... well, the North Star was originally designed for an engine. Maybe I should go with that. I can get an Aviastar .46 2-stroke off eBay, but if any of you think that's not a good idea, please say so soon, bidding ends in 29 hours. At the moment, it's just over

Edited June 7, 2014 by RedDwarfIV

[Tamiyacowboy]

a small .45 engine is going to be putting out about 800-900watts 

 

thats 4s -5s battery range. for electric.

motor wise your going to be wanting to throw fairly large props 

11 inch maybe 12 inch 

 

something like this type of motor 

 

http://www.horizonhobby.com/products/super-cub-dsm-rtf-EFLM4046A

[RedDwarfIV]

a small .45 engine is going to be putting out about 800-900watts 

 

thats 4s -5s battery range. for electric.

motor wise your going to be wanting to throw fairly large props 

11 inch maybe 12 inch 

 

something like this type of motor 

 

http://www.horizonhobby.com/products/super-cub-dsm-rtf-EFLM4046A

The problem is, 10" is the largest prop you can fit to an unmodified North Star. And as I said, there's no electric system in my price range that could propel a North Star, hence the decision to switch to glow engine.

 

Also, as coincidence would have it, that is the exact motor I was looking at when I decided electric was too expensive. That motor is $90. That's

Edited June 7, 2014 by RedDwarfIV

[RedDwarfIV]

...

 

Bidding on eBay is seriously nerve wracking. But despite that, I am now the happy owner of an Aviastar .46 2-stroke engine, capable of spinning a 10" prop, and a heck of a lot cheaper than going electric.

 

It cost

[hydro]

stick with a 2blade prop as 3-blade will not  give extra performance there more for a scale look

[RedDwarfIV]

The day before yesterday, an AA 4cell battery holder arrived in the post. Yesterday, I connected it to a receiver battery connector, and plugged it into the Futaba receiver. I also plugged in the navigation lights. Using the throttle control on the Perfex controller, I got it to switch lighting modes.

 

I'm pretty happy with that.

[RedDwarfIV]

IT BEGINS

 

 

 

The glue is waterproof, not just water resistant, since it's been mentioned that's important.

Edited June 26, 2014 by RedDwarfIV

[RedDwarfIV]

First phase of wing construction compete.

 

 

 

Also, the prop reamer and spinner arrived today. I made the prop's shaft hole wider, then fitted everything to the engine. Going to paint the propeller later. I should mention why I'm using a 3-blade when I asked about that before and you said go with 2-blade. Well, for a start, the 10" prop I had? Electric only. So I needed to get a new one. The 10" prop was stil good for working out stuff, so I kept it. I put it on the pans and found the tips would almost certainly hit the fuselage. Which meant I needed to get a 9" prop. Fortunately, after not much Google searching, I found an example of a Northstar with a 9" prop that apparently flew very well. Its was a 9x5"x3. The one I have is a Graupner 9x7"x3, and on the website was listed as being equal to a 10x7"x2.

 

Plus, I do like the 'scale look' as you put it.

 

[RedDwarfIV]

Figuring out where to put the lights.

 

Also, much progress has been made, though stalled by my kit missing a number of balsa sheets. I bought more off eBay, so that shouldn't be much of a problem after they arrive.

 

In the mean time, I've been setting up the control rods and the navigation lights, since both must be done before certain parts of the sheeting can continue.

 

[Tamiyacowboy]

looking good. 

 

if you dont mind a little extra wieght. you could use mcdonalds straws

glued into the wings to act as ducting lines for your lighting looms.

just leave a small square hatch sized opening on the top wing skin

and when sheeting out leave this small hatch open, when you come to covering with the finishing film.

just go over as you would.

 

now if something happens and lights fail your craft knife cut the hatch out of the film covering.

make your repair ( use pre bent long threading needle to pull wires through tubes.)

once repair is finished lights work you just pop a covering film patch over the repair hatch

and all done

[RedDwarfIV]

Thanks for the ideas. I wasn't entirely sure how I'd repair the lights. I'm still not entirely sure how I'll hold them in position without just glueing them.

 

Currently the wires are being run through rectangular holes I cut in the wing bars, similar to the ones you cut for the wing spars. I might try using McDonalds straws if I can get enough of them quickly enough. I do have some spare control rod sheathes, but to use those I'd have to cut holes in them. That wouldn't be great.

[RedDwarfIV]

I've been waiting for ages for the two longer, more flexible control rods to arrive so I could start on the remaining sheeting and fix the wing in place. They finally did, so I put them in position, and worked on those things I mentioned.

 

The lights' wires were run through small trunkings, although any proper maintainence of them would probably require removal of parts of the plane.

 

I also had to cut an access hatch in the battery bay.

 

[RedDwarfIV]

WELL, ME, IT TOOK YOU LONG ENOUGH!

 

After a very long time in which I just couldn't get myself to work on it, I've had a sudden urge to do loads now.

 

 

I actually had to remove those trunkings because they would interfere with the flow of air under the wing. The amount of work involved was what kept putting me off, but I finally went ahead and did it. Admittedly I now would have to remove entire wing covering sections just to repair wires... but so far, the wires themselves haven't proven themselves to be the least reliable part of the lighting system.

 

Having fixed that, I sanded the wings' leading edges. After that was a few weeks in which I was too busy with trying to get JSA, trying to find a job, and trying to keep my JSA that I couldn't work on it. In the past few days though, I glued panels to the sides of the lower tail, glued the wings to the fuselage, added that bit that goes over the wing, fixed a sponson and started work on the front part of the lower tail. I expect to keep this up for at least a little longer, and might get so far as the nacelle this time.

[hydro]

its coming on great mate it makes a nice change to see the build from the start so lets see you finish it and see it flying