Kwikfli

I recently got a BalsaUSA NorthStar. Need Some opinions on building, engine, covering etc. I Have three engines for possible use. A well used K&B .40, a Magnum 52XLS and a O.S. 55AX. Seriously considering the .40 because of weight, and everyone says the 50 size engines won't like turning a 10" prop, which is pretty much the size limit for this plane. Am also considering sheeting the bottom of the wing with 1/64 ply. Any thoughts on this. As of now considering useing Coverite because I've been told it can take the abuse of landing on water better than some of the other film coverings.
Thanks for any help.

Kwikfli

JustPlaneSweet

Kwikfli,

Note that there is a printing error on the plans, the left and right sides of the wing are not symmetrical. Pick a side and transfer the rib positions to the other side of the plans before you build.

I had an Irvine 53 in mine and it flew great. Of the engines you listed, I would go with the Magnum 52XLS. The only reinforcement I did was to replace the first four inches of the bottom sheeting ahead of the step with plywood. This area takes the most abuse.

I have not used Coverite, so I cannot offer an opinion. I used regular film covering.

Stan

VIRGINIA MODEL BUILDERS

My Feedback: (159)

am considering building as well your info has helped

Augie11

I've got the .55AX on mine turning a 10x7 three blade. Engine handles it just fine. Also yes, I did use 21st Century and it's held up very well-now into 3rd season (I float fly once a week). I sheeted the whole bottom with 1/64th ply, nothing on the wings. Oh, you might want to add a water rudder as she doesn't handle that well on the water taxiing in a stiff breeze.

Good luck!

vpresley

My Feedback: (162)

With the construction and Delta wing, I doubt it would fly very well if at all on the K&B 40. The other 2 engines would be better. Use a higher pitch prop in the 10 inch size, say a 10-8 or a 10-10 to keep the diameter down and make it more flyable. My friend had one of these that flew well on a Thunder Tiger Pro .46. Watch the elevator servo linkage. As built its a little mushy because of the long Nyrod to elevator connection. Keep the Nyrod braced as much s possible along the length of the run. If you dont you will seem to run out of elevator if the Nyrod flexes. Also dial in some Exponential on your radio if possible to soften the aileron center point.


Vince

MinnFlyer

My Feedback: (4)

Ditto on the plywood forward of the step. Doing that, you can skip the fiberglassing.

I would also go with the Magnum with a 3-blade prop. While the 55AX is a better engine, I prefer not to use my best engines in seaplanes lest they get dunked. I've got an old OS 46SF on mine with a 10x7 (2-blade) prop and it screams!

Plywood sheeting under the wing is not necessary. Use 21st Century (Coverite) fabric to cover at least the bottom of the wing and you're good to go.

alpinestar

Add a water rudder for sure! my maiden (without one) was interesting... Add a ply mounting point to the bottom of your rudder while you're building. My water rudder hangs below the air rudder about 1-1/2" and is about 2" or so long & does the trick well.
I used a micro servo in the nacelle for throttle & used ply on the forward fuse bottom.
Lite-fab, klass-kote epoxy, Jett-50.
Fun! No provisions for wheels; water only.

MinnFlyer

My Feedback: (4)

Ditto! We don't need no stinking wheels!

If you have a grass runway, you can takeoff and land right on the belly!

aa1a

My Feedback: (4)

There is a very good discussion of Northstar Mods under Seaplanes. I've built two. The first one was completely stock. The second one has many mods. I put the elevator and throttle servos in the pod. The elevator size has been increased. I used 2 aileron servos, and the aileron and rudder servos have been moved forward. The second (purple) one came out a little heavier but the shorter throttle and elevator linkages are so much less trouble it is well worth the weight penalty. I kept the belly balsa and glassed it. I am very happy with the performance with the 46 AX with the tuned pipe. I see no need for a larger engine. The plane is way faster than my fingers.
Jim

SeaJay

My Feedback: (6)

AA1A,

OH MY GOD, I just love the looks of that Transparent Blue on the wings on that Northstar in the 3rd pic.... I think I might just have to do something very similar..

Craig..