The double coreless tail mod guide

[Lipper]

Hi Guys,

I tried the SR120 tail motor and didn't like it. Too heavy and too much power. I figured I would give this a try with MCX-2 motors. I couldn't find the mcp-x tail-motor holders so I used this small block of plastic (some kind of nylon) and drilled a couple of 6mm holes in it for the motors and a 3mm one for the boom.

I'm using the stock tail-motor wires. Do I need the SR120 wires to get full power from the two motors?

Thanks - Ken

[liftbag]

Originally Posted by Lipper

Hi Guys,

I tried the SR120 tail motor and didn't like it. Too heavy and too much power. I figured I would give this a try with MCX-2 motors. I couldn't find the mcp-x tail-motor holders so I used this small block of plastic (some kind of nylon) and drilled a couple of 6mm holes in it for the motors and a 3mm one for the boom.

I'm using the stock tail-motor wires. Do I need the SR120 wires to get full power from the two motors?

Thanks - Ken

In my opinion, yes. But if you do not have it, try it with the original wires. If during hard maneuvers the tail loses, then try at least to double the wires.

[Spunjah413]

Originally Posted by Lipper

Hi Guys,

I tried the SR120 tail motor and didn't like it. Too heavy and too much power. I figured I would give this a try with MCX-2 motors. I couldn't find the mcp-x tail-motor holders so I used this small block of plastic (some kind of nylon) and drilled a couple of 6mm holes in it for the motors and a 3mm one for the boom.

I'm using the stock tail-motor wires. Do I need the SR120 wires to get full power from the two motors?

Thanks - Ken

Why 3mm for the boom? The logical thing would be 2mm as to save weight, especially for this tail heavy setup.

[RedOctobyr]

Nice job, Lipper! I haven't seen anyone simply make their own tail assembly. That's cool. How does the boom stay in the block you made? Did you glue the boom in? Is the boom 2mm or 3mm diameter?

[Lipper]

I had one of the microheli metal tail holders with a 3mm hole for the boom so I went with 3mm. Also, the 2mm seems to have too much flex. I think it might have been "rubber-banding" the tail.

I just shoved the boom into the hole I drilled - no glue. Seems to stay in pretty well. I also stuck a piece of 1mm rod into the bottom, at an angle, to keep the rotors off the ground. It's the simplest, lightest way I think.

[liftbag]

Originally Posted by Lipper

Hi Guys,

I tried the SR120 tail motor and didn't like it. Too heavy and too much power. I figured I would give this a try with MCX-2 motors. I couldn't find the mcp-x tail-motor holders so I used this small block of plastic (some kind of nylon) and drilled a couple of 6mm holes in it for the motors and a 3mm one for the boom.

I'm using the stock tail-motor wires. Do I need the SR120 wires to get full power from the two motors?

Thanks - Ken

Great job, especially in anticipation of future demise of old style tail motor mount.

But you have mounted the left rotor the wrong way.
The rotor loses much of its effectiveness mounted reversed

[liftbag]

As I advanced two more tail motor mounts, I realized this variant, which should prevent twisting of the tail boom, when the thrust of the two motors is very high.
Each motor act of opposing lever arms and the resulting torsion is zero.

The tail works very well, equally to the other three that I have, so I can not tell if this variant is a real improvement.

I'm tempted to ask to Rakonheli if they may be interested in an upgrade so unusual.
But I have serious doubts about this, because this mod does not work well with the standard main motor.

[baui2000]

I liked your original double tail mod and was going to try it, but this one I'm sold.

[Lunar]

Originally Posted by liftbag

.......... because this mod does not work well with the standard motor.

I thought you were using 2 of the stock tail motors?

[baui2000]

Originally Posted by Lunar

I thought you were using 2 of the stock tail motors?

Those are 2 BMCX2 motors on brushless mCPx. Read the first post of this thread "Can be used it with stock brushed main motor?" section mainly.

[liftbag]

Originally Posted by Lunar

I thought you were using 2 of the stock tail motors?

No, is not the double tail itself that doesn't work, but the whole rig.
The tail begins to malfunction, if too much current goes into the 3 in 1.
The same thing happens if (with brushed main) you use the 120SR tail mod, or the 4G3 brushed instead of the stock main motor.
In addition, if the current exceeds certain limits, the 3 in 1 comes in over current protection.

Is for these reasons that I personally do not recommend this mod with a helicopter with brushed main motor.

[liftbag]

Originally Posted by liftbag

I'm tempted to ask to Rakonheli if they may be interested in an upgrade so unusual.
But I have serious doubts about this, because this mod does not work well with the standard main motor.

I sent them an email

[JAM3X]

Are the mCX2 motors more powerful then the stock mcpx tail motor? Should I replace my stock tail with 1 mCX2 motor? would it be an improvement (even if only slight)? I think my tail motor is going anyway, and was thinking of 120 sr mod but decided not cause its completly stock otherwise. I guess it will be more reliable tho(mCX2 tail)? Maybee worth a try? Or maybee a brushed walkera or helimax tail?

[adroc3905]

I have done the mod but when I throttle up the tail motors engage before the main rotor and my tail goes crazy thus knocking over the heli before liftoff.

Is there a TX mix setting or trick to preventing this? My Rudder is currently at 100% travel.

Thanks

[liftbag]

Originally Posted by JAM3X

Are the mCX2 motors more powerful then the stock mcpx tail motor? Should I replace my stock tail with 1 mCX2 motor? would it be an improvement (even if only slight)? I think my tail motor is going anyway, and was thinking of 120 sr mod but decided not cause its completly stock otherwise. I guess it will be more reliable tho(mCX2 tail)? Maybee worth a try? Or maybee a brushed walkera or helimax tail?

Neither better nor worse, it is the exact same motor imo

Originally Posted by adroc3905

I have done the mod but when I throttle up the tail motors engage before the main rotor and my tail goes crazy thus knocking over the heli before liftoff.

Is there a TX mix setting or trick to preventing this? My Rudder is currently at 100% travel.

Thanks

It depends on which converter/esc set you use, the main motor can be started more or less delayed than the tail (I assume that your helicopter is converted to brushless).

In fact, typically the converter sends the signal to start up only when the throttle stick has reached a certain value, whereas the tail motor starts immediately.

If you use a throttle curve larger than 55%, you should enter the hold switch and the Stunt flight mode (middle stick for zero pitch). Then release the hold switch to start. The 3 in 1 provides a soft start by itself (only if throttle has a value greater then 55%).

Using this procedure my helicopter remains stationary during the motor soft start.

Hope this helps.

[JAM3X]

did you try a walkera 4g3 tail motor? would this be an improvement over the stock mcpx tail? have you heard of any single motor that could be used with the stock set up? how bout a trex 100 tail, is that brushless?

[liftbag]

Originally Posted by JAM3X

did you try a walkera 4g3 tail motor? would this be an improvement over the stock mcpx tail? have you heard of any single motor that could be used with the stock set up? how bout a trex 100 tail, is that brushless?

Look here

[RedOctobyr]

Liftbag, can you tell me how many teeth are on the mCX2's CCW motor's pinion? Just wondering if perhaps it is the same 8t pinion as the stock mCP X motor. If it were, ordering one of these would get me a tail motor, and maybe also an 8t pinion that I could drill out for using on a BL main motor

[HeliBenj]

Hey liftbag, Great guide, thanks heaps.

Stupid question, I have a msr (and a mcx). I understand the mcx motors are no good.

Can I put the msr tail motor together with the mcpx stock? Why do the motors have to be the same?

Thanks!

[learjet3]

I just finished flying after doing your dual tail mod and I have to say the tail is now ROCK solid! With this mod and a brushless motor you can really throw this little heli around. I am thoroughly impressed.