E7 Tail Performance

[Matt Botos]

Belt slipping?
Tail making noise?
Tail blowing out?

I've been getting a few questions about how to make the E7 tail rotor perform like my personal E7 performs.

Electric helicopters have much more torque than nitro helicopters which translates into a higher demand on the tail rotor system. Inadequate tail blade size or head speed can result in tail blade stalling. Once the tail blades are past the stalling point the belt will skip teeth and can potentially break the belt.

Here are some factors that can affect E7 tail performance.

1. Tail rotor performance is relative to your head speed.
2. When running slower head speeds 1900 - 2000 you should increase your tail blade size.
3. When running higher head speeds 2200-2250 you can easily run 106mm blades without issue
4. Heavy cyclic and pitch at the same time (ham hands) will blow out any tail. Adjust your cyclic and collective to meet your collective management skill level.
5. The heavier your helicopter, the higher the disk loading. The higher your disk loading is the harder your tail must work to counter act torque. Run appropriate size tail blades if you are running heavier batteries.

Here are my recommendations based on head speed.

Head Speed------Tail Blade Size
1900-2000        110-115mm
2150                 110mm
2250                 Rail 106mm (they have 30mm cord for nearly the entire length)

Do not let your tail belt slip! It will eventually break as it is too much trauma for any belt to handle.

Thanks,

Matt

[RyanW]

[JVZ]

Can you hear or see something in the heli when flying that shows the belt is slipping? My kit is on the way just preping myself.

[Matt Botos]

If you are building it as an E6 then you have nothing to worry about.
If you are building it as an E7 they belt tension is critical. Most of the time when the belt slips the pilot is moving very fast while using rudder or is being very aggressive with collective and cyclic at the same time.

Thanks,

Matt

[JVZ]

Thanks Matt!

Yep, going E6

[Matt Botos]

Cool! Pull it tight and forget about it!

Matt

[Jamin_00]

Ah, not seen this post.

On my E7 I plan to run below 2000 with the occasional 2200 mad blat.

I fly fast big air with lame 2.5D attempts tic tocs, rainbows and inverted tail first hurricanes about as 3D as I can go.

Would I be ok with 110mm tail blades?

I got 105's ATM and it does feel a little loose but it's still early days and only about half a dozen flights or so, so still in the tweaking phase and getting used to it

Any advice greatly received

[RyanW]

Hello Ben,
   I run 1900 on the E7 as well. Going from 105mm tail blades to 110mm made a big difference for me. I have a set of 115s, but haven't tried them yet.

   My first test for the 110s was at an airshow a few weeks ago and we had 28+ mph winds. I bumped the headspeed to 2050 (my idle up 2 setting) and the machine did really well. The power to weight definitely helped in keeping the machine grooving for the demo flight. They asked if I would still be able to fly in that wind (side note- it was 48mph just 1000' up). I said "sure, I will just go really slow in one direction and REALLY fast in the opposite direction" 

[Jamin_00]

Cheers,

Will grab some 110's and see how I get on then

[RobBarnes]

Matt, are you planning to make any 110 Rail Blades in the future please ?