Axe CP brushles upgrade trouble. Warning, kind of long
 

So I'm pretty new to the new heli thing. Been into RC cars for as long as I remember.

I've got an Axe CP, never really learned how to fly it well, but being a mechanical engineer dealing with automation and high technology such as brushless servo motors, I just had to put a Hyperion P1919 M06 motor on it, put a 15tooth pinion on it. Worked OK for a few days, I also paired the motor with a 35A hyperion ESC. I love the adjustability. And just to let you know I did go overboard here, I've been fully expecting to upgrade to a Trex or similar, it is just way too windy for the Axe where i live.

So now the problem. After a few flights and crashes(have checked linkages and main shaft, everything is very smooth and straight there) and what not, I could not get the tail to hold at all. This was upgraded with a gy240, when I bought a 7ch futaba heli radio. (going to be getting into planes here as well) I set the radio curves very simply, measure my min and max pitch, followed some advice with the collective mixing, and everything worked out great.

Then I started frying direct drive tail motors trying to keep the machine from spinning. Figured I needed more tail power so I upgraded to a little terror of a hyperion 12mm motor direct driving the tail. Helped a bit but over heated and shut down.

Is there something obvious I'm missing here? Oh, forgot to mention that I'm running plastic trainer blades.

Please give my overly obsesive techno brain some advice.

Regards,

Steve

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

did you try adjusting the gain on the gy 240? there is also a switch on there to go from normal to rev try switching it to rev. you may have tried this already but you didn't say, anyways i had the same problems.


anderson

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

Yes, I've adjusted the gain, and the switch is set correctly. I can make it spin like a top with the rudder, but only if main rotor isn't spining.

Maybe the training blades just are effecient enough, I'm not sure, I think that is the next thing I'll try.

Thanks for the suggestions.

Steve

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

I thinky your main motor is way to much for the tail motor to compensate for the torque put the brushed motor back on the main and you will be fine (im running the stock brushed main motor, and a brushless tail motor setup a 12-30-3850 sized motor and a 12A esc and a telebee HH gyro)

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

Yeah, the main motor is wwaaaay to powerful for the machine. This should not matter when geared correctly though. I had a 15 tooth pinion on it, so I think the head speed was way to high.

I did actually make some headway though. I dropped the main motor pinion down to a 12 tooth and turned off the speed limiting for now.

Tail actually snaps back from 45 degrees if I put in too much throttle too fast. Only problem is the tail motor does get a little toasty.

So it is either heat sink the tail motor, or go back to the stock main motor. Brushed main motor is probably the best way to go, but damn I love all the adjustments on the Hyperion speed control.

I'm still thinking I'm going to put the brushed back on, until I can get my skills a lot better and actually be able to use the good hyperion gear.

Thanks for all your help! Even though my local HS sells choppers, they are not very knowlegable, so it is great to have this forum.

Steve

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

Toss the electric tail motor and get yourself the Belt-Drive kit, or the new shaft-driven (torque-tube kit). There is NO comparision between the WEAK & WIMPY [:'(] (ETM), and a DRIVEN tail rotor with true positive & negitive pitch :D!

Did the conversion over 2yrs ago on my AXE CP v1, and never looked at an Electric-tail again!

Also, your BL main motor is way more powerful than you really need, your headspeed must be somewhere around 2800 RPM's!

To figure out the headspeed in RPM's= (Motor Kv * Nominal battery voltage * 90% effiency * Motor Pinion tooth count)/Main gear count. EXAMPLE: 3700*11.1*.9*14/186= 2782 rpm's

Shadow

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

Try using a faster, stroger tail motor. It is nice to experiment if you have the time.

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

Hello Shadow99,

Can You tell me where You saw the new shaft driven(torque tube) kit for the axe cp?

RE: Axe CP brushles upgrade trouble. Warning, kind of long
 

You can try the heat sink on the Hyperion tail motor to keep it cool, but I would recommend a larger tail motor and even a larger tail blade. I'm running a 10 gram brushless outrunner and a GWS 4.5x 3 prop.