Hobbyking Bonsai EPP Wing 600mm (ARF) - Get if faster

Timeless

Junior Member
Hello People.

I'm having some troubles with my Bonsai wing. Let me explain my current setup first:

  • Hobby King GT-2 2.4Ghz Receiver 3Ch
  • Hobbyking Bonsai EPP Wing 600mm (ARF)
  • Turnigy 1811 brushless Outrunner 2900kv
  • Turnigy nano-tech 460mah 2S 25~40C Lipo Pack
  • APC Style Propeller 5x5 (2 pc)
  • Robbe ROXXY BL CONTROL 710 ESC (10amp)
  • Turnigy TG9e 9g / 1.5kg / 0.10sec Eco Micro Servo (2 pc)

My first toughs ware low weight and cheap. so thats why I bought 9g servos instead of 5g or even lower. because they are more expensive than the 9g @ the Hobbyking EU warehouse. For the rest I bought an 3ch hobbyking receiver to fit my Turnigy 9x TX and save some grams because the 9x RX is heavier than the 3ch GT-2.

This all does the job, but I did not open this topic just to say my setup is working.
Maybe you already guessed but yes this setup is pretty slow.

This Turnigy 1811 2900Kv is a great little bugger, but it's simply not powerful enough. at least not with an 5x5 prop on it. 6x3 or 6x5 are a little bit to big for this motor. And after all these wires are so tiny and stiff that they keeps cracking and disconnecting from the 2mm plus no matter what I do. I use some Shrink tube to get them more secure but I don't know for how long it will last.

And because I've flown my wing for several hours and days i really like something faster now. I've got some other planes to fit my needs. but I want to upgrade this little bonsai to get the job done. So giving me advise about another plane is kind and appreciated, but this is not why I opened this topic.

I need to find some motor that need less than 10Ampaires, because I'm currently limited to my 10Ampaire ESC and I don't want to waste that little thing if it can be useful. I've got several 3cell lipos here so that wont be an problem.

I've found some possible candidates both with 2mm plus that fit my 2mm plugs on my ESC:

  1. Turnigy Aerodrive SK3 - 2122-2100kv Brushless Outrunner Motor (EU warehouse)
  2. Turnigy Aerodrive SK3 - 2118-3100kv Brushless Outrunner Motor (EU warehouse)
#1 had been advertised by someone that reviewed the bonsai at the bottom of the EU bonsai page. he does get 60KM/h with this motor so that would be fast enough for me. But since this motor is currently not available I found #2 which has an higher KV rating but lower A and lower P(watt).

  • What is for the bonsai a better motor? Higher [KV] or Higher [P], Less [P] will give me a longer flight time. but will it go as fast?
  • maybe there are some better motors available from the EU warehouse that will fit my needs?
Regards,
Timeless

Ps. I also asked this question on RC Groups. but I want to get multiple opinions. so thats why i double posted the same question on multiple forums.
 
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aiidanwings

Senior Member
I cannot remember the exact details, but the last 'fasterish' plane I destroyed had a 28something 1200kv a 9x7 prop cut to 5 inches, 60amp detrum esc, and a four cell somewhere around 400-600 mah. It was really fast. It looked amazing when it disintegrated over the trees.

Anyway.. I think a four cell conversion will give you the performance you want. The Grayson Hobby Park jet combos are great. A plus about the higher voltage is that the amp draw should be lower.
 

Timeless

Junior Member
oké a 4 cell would be to much for this little plane I guess. I've got several 3cell lipos and my ESC supports 2-3Cells. so 4Cell is not an option for now.

60Amps ESC is also a little bit to heavy I think, this plane will get an to high glide speed. Thats why I thought about the Turnigy Aerodrive motors. they are lightweight and don't drawn to many amps so ideal for my little 10A ESC.

Thanks for your suggestion about the Grayson Hobby Park Jet but as i said : I've got some other planes to fit those needs. but I want to upgrade this little bonsai to get the job done and going faster. So giving me advise about another plane is kind and appreciated, but this is not why I opened this topic.
 

jd7792

Senior Member
I built a scratch build delta wing, very similar but slightly bigger to the Bonsai.
I used a 1500Mah 3S set up thru a 30amp ESC running a Rctimer motor that I mistook to be a 2200Kv only to later discover it is a 2650Kv motor. On this a 6x4 prop and it is literally a rocket! To the point I am considering changing this motor to a 2200Kv and using the bigger one on another build.
I had no heat problems, more speed than I am use, and to be honest was comfortable with and AMAZING vertical flight.
Hope something here helps?
 
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Timeless

Junior Member
Tanks for your advise and your own flight results.:D

so a 2650KV on 30amps ESC was almost to fast? like u said "more speed than I'm use" since my ESC thats already on the bonsai limits me to only 10Amps and a 2122- 2100KV on a 3cell should do the job right?

Does the difference in power 63W[Aerodrive SK3 - 2122-2100kv ] vs 42W[Aerodrive SK3 - 2118-3100kv] (+21W) mean so much? Whats better for my bonsai? Higher KV or More Power? any advise?
 

jd7792

Senior Member
I am sure that there are others with a lot more experience than me that could give a better answer but I will try anyway. The higher Kv will give more thrust with a smaller prop and I tend to like the 6x4 or 6x5 props which work very well with 2200Kv motors. I think a wing should have a fair amount of speed simply due to the nature of the beast! But a smaller motor will give a larger prop a relative speed but I'm not sure how it would effect the performance of the wing in general. Hopefully someone will dive in here with some more specific advise for you! Remember I thought I had a 2200 on my wing until I double checked and realised it was much larger. I intend trying it again soon as is before making a change to a 2200Kv. From what you have said I think a 2100Kv would be a good size motor for your set up but you may need to put a larger ESC in. I personally wouldn't run a 10 amp ESC as I would be frightened that it would burn out and cause some serious damage, but thats just me. I am keen to see what other pilots have to say to this thread. Let me know what you decide and how you go.
john
 

Timeless

Junior Member
Thanks for you own experience.

I thought just give it a try and error. and see what happens. So I bought both
Turnigy Aerodrive SK3 - 2118-2750 Brushless Outrunner Motor
Turnigy Aerodrive SK3 - 2122-1800kv Brushless Outrunner Motor

I tried both with an 5x3prop. First I gave the 2118 a go. It went fine, not the speed that I was hoping for. But at least it went faster than the 1811 motor. After 3 minutes I suddenly felt less thrust so I landed my bonsai and saw that the motor wires moved to the direction the motor was running to. So after some inspecting I find out that the motor coil is movable. Seems that the glue has loosened. I already made a support ticket on hobbyking. and hoping for an replaceable item.

After this tragedy. I tried the 2122. Damn, that thing gives a lot of thrust especially on a 3cell. The motor doesn't even get warm. After running my 2118 with an 2cell and a 5x5 prop the motor the motor get really warm. Maybe this is because the prop is unbalanced(Bonsai is vibrating allot) or the 2118 is just not made for this propeller.

The 2122 does give me great thrust, but still doesn't give me the speed I want. So my question to you guys, Since the 2118 is getting hot on a 2cell with the 5x5 prop. is it recommencement to run my 2122 with an 5x5 prop or 6x3 on a 3cell? if yes then I will buy an 5x5 or 6x3 GWS style propeller, instead of the 5x5 prop I have now
 

klaw

Junior Member
Firstly, try to balance your prop. It's not difficult or time-consuming to do, and the reduction in vibration is totally worth it.

there's not a lot of data around for the 2122 so your best bet would be to try it on the ground. Just strap it to a bench or something, run it up to full power for a few seconds, and check for overheating ESC and motor. If you can, borrow a watt meter or something to check your amp draw. I reckon the 5x5 would be about right, but just take it easy for the first flight so you can slowly build up to full speed without damaging anything.
 

Timeless

Junior Member
Ive tried to balance the 5x5 prop I had. But the hole is off centered I see now. and even with 4 turns of tape(the tape people use for packaging presents) the prop still vibrates. I use a laser to see if one of the 2 blades is unbalanced.

The 5x3 Props thats been great on the 2122 is also more flexible. the APC 5x5 prop is stiff and sharp. The GWS 5x3 is much more flexible and has soft edges. Maybe I buy those in 6x3(currently out of stock) and some TGS 6x4e and TGS 5x5e. I've much better experience with those propellers instead of the APC.

My current results:

2122 on 3cell:
APC 5x5 = Very hot, almost to hot to touch after 10 seconds. Didn't fly with it yet after this test.
GWS 5x3 = Barely warm. does fly great, but not as much speed as I expected

2122 on 2cell:
GWS 5x3 = Cold. does give me a little thrust to fly at full throttle. but the speed is dramatically low.
APC 5x5 = Untested

---------------------------------------------------------------------------------------------
2122 on 3cell Current(A)
APC 5x5 = 12,3A
GWS 5x3 = 6,8A
APC 6x4 = 9,8A

Since the motor has been rated for 7A max, the APC 5x5 and 6x4 are out of the picture. The GWS 5x3 runs on 6,8A so maybe I can go for an GWS 5x4 or GWS 6x3 to get the maximum performance out of this little motor.

Since my 2118 isn't working as it should be. Maybe I can buy the 2122 - 2100Kv as an replacement if it has been restocked in the EU warehouse. so I can gain more speed from those propellers.
 
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