Ohh by the way, friendly tip....dont choose a hobby table that is dark like mine. Makes it very difficult to find screws or genreally see anything on the table...

I noticed your motors are with 2500KV, probably using 2S lipo can be good enough if you apply prop EP5030 on them. A friend of mine applied the same motor, AX-1806N, on his scratch built plane using the same prop and 2S. This setup worked great for him, I bought the same motor but with 2100KV. This is the first high KV motor that I've ever bought.
Chen

Hey guys.

Decided to do some major surgery to my plane; as I have found a battery box; so instead of making a hatch through my roof, I wanted to put this instead. I had to take out a considerable amount of foam to get it in; but hopefully it will make the hull stronger since it's made of plastic. I didnt weigh it, but it felt pretty light. I also had to change the way I make the nosewheel steering, so I have put in a separate steering servo. I dont think it will be too much over weight, since the stock motors amount to over 100 grams; and my small motors weight under 50 together.

Also, have a look at my motor mount; do I need to worry about the thrust line too much on this since it's a twin? It looks to me as it will have a slight down thrust now; I can adjust it a little with washers if needed.

This build has taken me so much longer than anticipated; just because of the added complexity with brush-less motors and the need for two ESC's... this thing better fly as good as I am hoping.

The next job now is to extend the motor-wires and then figure out how to hook up the battery and ESC's. Guessing I need to connect the ESC's in parallel for battery connection, and use a Y cable for connecting to receiver, and cut one of the red cables so I only use one of the BEC's on the ESC ? Does this sound about right?

- Steffen

Looks like all systems are go! The space under the wing is really really cramped; I'm glad I got a battery box because it would be an absolute nightmare taking the wing on and off.

Both motors spinn good; but I'm not so sure with the balancing; but I will give it a few flights before I start messing with it... Just need to reverse both motors, they both gave forward thrust (would be awesome to have that for landing though... just a button that would give me 10 % reverse thrust)...

This may have taken me 20 hours or so... I wont be doing something like this again anytime soon.... pitty; because I absolutely love twins...

Steffeo,

Good luck with your maiden. It was my intent to also use duel brushless motors until I saw the work involved. I decided to go with the stock brushed motors instead.

My BN2 is happier flying faster than slower, tends to drop a wing when stalled.
Something I learned/tried today was to round the LE of the wing from the motors out to the tips. Now I only had two flights with it today but I'm convinced it greatly reduced the tendency to tip stall and flares much better for a landing.

Keep us posted and good luck.

Bart

Alright; so the maiden has been delayed due to a stupid error on my part setting the plane up.

I was going over the servoes and reversing them....when I accidentally reversed channel 3... With two 5030 motors on 3S on full whack, heading straight to me; it took some time realizing what I had done; so I believe one of the motors are dead;

I haven't had time to inspect the damage; but I got a few cuts on my hand and arm.

I will try to get time this week and look for any damage; if both motors work; I will maiden it this weekend weather permitting.

So, lesson learned; do not....do not.... reverse channel 3...

Originally Posted by Steffeo

...
So, lesson learned; do not....do not.... reverse channel 3...

Better yet, remove props when doing any of this kind of tweaking.

Finally got around to inspect and test; I first thought one of the motors were dead; changed the esc around, and the motor fired up again. So I assumed the esc was a gonner, and thought I might as will take of the heatshrink/plastic to inspect... turnes out; it's just fine, I just forgot to plug in the y-cable to the receiver...

So now I have an esc without the headshrink... Any tips to what I could do about this? What kind of heat should I expect my fix to endure?

I could just buy a new one; but the soldering is a right bitch and I would like to avoid if possible. Pending the repair I will be maidening it (outside) next week.

Never mind; I used duct tape... but I have seen a small design flaw; I need to move the servos out on the wings; there just is not room for the servos to move freely inside the fuselage..

Well, I have gotten in up in the air. I'm not really all that happy with it. It doesnt have that little pinash (or what you call it).... It's quite loud; and not really all that fast, just alot of noise at full throttle but not really any more speed compared to 2/3 throttle.

Having some issues with it being nose heavy I think, elevator input when power is off is quite poor, and it need alot of up elevator to keep it's nose level.

Running two-blade prop now, I think next step is to check amp-draw and see if I can put some three-blades on there.

Also having issues with the nose-gear since elevator input is so bad I'm having problems making smooth landings. I remember with my old brushed (and nimh's) bn-2 that it was really a smooth lander, easy to point and almost everytime I could flare properly and land smoothly...

I havent check the weight of it yet, maybe it's too light now, perhaps it deserves some more weight to make it more stable.

Steffeo,

A high KV motor certainly makes a lot of noise at full throttle, but a well balanced prop can reduce its noise, and draws less Amps as well. Probably you have to check the two props to see if they are well balanced, if not, add clear tape to the tip of the lighter blade until you make it.
Always pay attention to its smooth curves when adding tape to the blade.

Chen

I did balance them out with some tape actually, and it did help a lot; but I suppose I cant do much with the motors spinning a certain rpm unless I change them out to a lower KV motor. But then I would need to have a bigger prop and I have no space for that...

I will check the amp draw and see if I can use three bladed props instead.

Any idea about the elevator not working all that good? Would a nose heavy plane behave like this ?

Last test run the CG was about 1 cm ahead of the big round shape in the wing. I would guesstimate about 2 cm from the leading edge...

Originally Posted by Steffeo

...
Any idea about the elevator not working all that good? Would a nose heavy plane behave like this ?

Last test run the CG was about 1 cm ahead of the big round shape in the wing. I would guesstimate about 2 cm from the leading edge...

Oh yes, you are VERY nose heavy, and that alone would diminish the elevator authority and require constant up elevator deflection to even fly level! See the CG location in the manual and balance there.

This may sound mundane, but are your props on correctly for the direction your motors are spinning?

Alright, i will sort out the cg then

Well, the props are facing the right way, but i do have counter rotating props, i dont know what it would be like if i have the props on the wrong side.

However I am not really unhappy with the speed or power, it has good power for climbing, not vertical but a very steep climbout.

I am more unhappy with the sound, its really screaming, kinda like when you are running full throttle in first gear of your car. Do you know the KV of the stock 300h motors?

Originally Posted by Steffeo

Alright, i will sort out the cg then

Well, the props are facing the right way, but i do have counter rotating props, i dont know what it would be like if i have the props on the wrong side.

However I am not really unhappy with the speed or power, it has good power for climbing, not vertical but a very steep climbout.

I am more unhappy with the sound, its really screaming, kinda like when you are running full throttle in first gear of your car. Do you know the KV of the stock 300h motors?

I've never used the brush stock motors in mine. I have small 2710 kV brushless outrunners spinning APC 6x4 counter-rotating props in mine. It will go straight up, but mine was converted to a seaplane from the beginning, so no LG. And I use a 1300 mAH 3S lipo, so it's pretty light. I also have no rudder and use differential throttle to yaw the plane.