Tail Servo for the HK450 Helicopter

Now this is an area where a lot of debate can happen, but I look at it this way, your tail is your heli, without it controlled well and fast you will loose your heli.

I use the MKS DS480 because of its speed and strength and its weight.

There are so many factors to consider for your tail
1. Accuracy
2. Speed
3. Strength
4. Gyro
5. BEC
6. Rotor Speed
7. Rotor Pitch
8. Blade Types
9. Heading Hold Setup
And there is probably more because everything effect the way a tail holds
Let’s take speed, if your head speed is slow let’s say 2500 rpm your tail will be slow and therefore wont swing the heli back to a straight position even if you have the fastest gear.
Let’s take travel, if your tail servo doesn’t travel the entire distance of the shaft to control the pitch of the tail again it doesn’t matter if you have got the best gear, you simply won’t be able to hold a heading because there is not enough pitch in the tail.
So let’s assume you have everything else correct, then why would you choose a tail servo like this?
Here is why I chose this particular tail servo.
1. The speed is 0.06 seconds to travel the full swing of the servo (Speed is important)
2. The strength of the servo is 1.8kg force, (you only need 1 - 1.2kg force max)
3. High resolution (because it is digital this allows smaller precise movements)
4. Metal Gears, (in the event of a crash it stays together well)
5. Weight (You don’t want anything much heavier than this)
All in all I feel I have chosen the best digital servo in this weight category and price range. You don’t need to go to the extent, and you can use something that is a slow as 0.1 sec full swing and analogue. and around 1.5kg and that would suffice for most types of flight.
But since I got this servo and installed it into my HK450, I found one great thing, and that is when I have my 700W motor running the head at 2800 rpm and I do a punch out at 12 degrees positive pitch, well this tail servo holds the heli perfectly, the tail of the heli doesn’t even flinch towards the right, there is no little swing and then swing back, it holds perfectly straight as it does when hovering.
Regards
Elias Gourvelos (EatAtJoes)