Model Airplane News

Intro to 3D Flying

pitch instability makes it nearly impossible to find an elevator trim setting that works consistently.

RIGHT 360 (45-degree bank)

LEFT 360

(45-degree bank)

If you find yourself working to prevent a downward spiral in one direction, put in some opposite rudder trim. ;e rudder is trimmed when the plane feels the same during both left and right 360s.

to be on the cutting edge and are willing to commit the time and resources to prove to themselves and others that they have what it takes. Of course, every pilot also wants to fly 3D because it looks really cool!

Precision Aerobatics
Deflection
Aileron 10-15 deg. (10-20% expo)
Elevator 10-15 deg. (10-20% expo)
Rudder 20-30 deg. (10-20% expo)

3D tools

The 3D reference associated with certain airplanes indicates that the plane is lightly constructed and features large control surfaces capable of deflecting 40 degrees or more. Since most 3D flying takes place at very low airspeeds, large surfaces are necessary to maintain control authority when there’s not a lot of airflow to work with. A good 3D airplane will also have at least a 2-to-1 power-to-weight ratio and thus be able to hover at half throttle with power to spare.

There are generally two types of 3D airplanes. The first is a lightweight scale model such as an Extra, Edge, Yak, etc., with large control surfaces, a tapered wing, no dihedral and a symmetrical airfoil; this type of aircraft is capable of both 3D and precision aerobatics. The second type is a non-scale airraft, including many flat-plate-airfoil electric “foamies” that are designed primarily for 3D flying; consequently, these tend to make poor precision aerobatic airplanes. This distinction is important because it will ultimately

3D Stunt Flying
Deflection
30 deg. (30-50% expo)
45 deg. (30-50% expo)
45 deg. (20-30% expo)

Setup tips

There are numerous information sources on basic 3D airplane and radio setup, so I won’t rehash that information here. However, here are a few tips to help optimize your 3D setup and avoid some common pitfalls.

Any 5+ channel radio with dual rates, exponential, and mixing capabilities will work fine for 3D flying. You’ll obviously set up the high rates for maximum 3D travel and the low (normal) rates to provide the optimum travel for aerobatic flying, takeoff and landing. To stay focused on flying and not on flipping switches, it’s recommended that you put all your dual rate and expo settings on one switch (a “mode” or “condition” switch).

Next, increase the travel percentage in
your radio to the maximum (e.g., 150%).
This will offer the maximum servo resolu-
tion possible with a 3D setup. As a rule,
mechanically adjust the control linkages
to achieve the neutral control surface
positions and the manufacturer’s recom-
mended maximum surface deflections,
then fine-tune things with the radio.
Among other advantages, this will make
programming simpler when you start
flying and have to make adjustments.
Note that It’s common for control sur-
faces to have some degree of twist, so make
sure that you account for and “average”
the twist to set the true overall neutral
position of each surface. A common mis-
take is lining up the end of the aileron with
the wing tip or the inboard trailing edge of
the wing, and then have to make large trim
adjustments in flight because the twisted
surface wasn’t truly neutral to start.
Last, when setting up your high and low
rates, it is crucial that you repeatedly check
the physical deflections of the surfaces

influence how you set up and fly each of your planes. You wouldn’t be happy with the results if you tried to fly precision aerobatics with an airplane designed primarily for 3D (and vice-versa).

3D flying is where lightweight foam airplanes really shine, particularly when you are learning to fly 3D. Foamies are amazingly durable and fly very slow, so they enable you to fly low and close for better visibility. Plus, everyone makes mistakes learning to fly 3D and training on a foamie won’t break the bank during the inevitable ground impacts. A good 3D trainer will also have two aileron servos so that you can program flaperons and other mixes to aid in certain flight situations. The tradeoffs are that flat-plate-airfoil foamies don’t handle wind well, and their inherent