Frequently Asked Questions

What is 3D flying?
What kind of foam is used?
What kind of glue do I use?
Is a flat foam model good as a first airplane?
How do I get my plane to hover?
What kind of servo do you recommend?
Which speed controller should I use?
How do I select a motor?

Q:  What is 3D flying?
A:   It is a form of flying in which the model is taken through extreme maneuvers not normally realizable with a full-scale airplane, such as hovering and sudden reversal of flight direction. It requires good eye-hand coordination and can be done only after one has acquired some experience in traditional flying.

Q:  What kind of foam is used?
A:  The foam commonly used to build flat foam models is either Depron (www.depronusa.com) or blue foam. Blue foam is hard to get on the West Coast because it is used as insulation in colder climates. It can be found in Lowes or Home depot stores on the east coast. It is comes in a fanfold pack of 25 sheets measuring 2'x4'. One sheet is plenty to make one flat foam model. It runs about 2-3 dollars per sheet. There are some differences between Depron and blue foam. Blue foam has a thin plastic covering on both sides. This makes it much more durable than Depron and adds some strength as well. Depron is a bit cleaner to work with and has a nicer finish, but flexes easily. We have used both foams in many planes and prefer blue foam.

Q:  What kind of glue do I use?
A:  In our models we use epoxy and hot glue. 5-minute and 15-minute epoxy both work well for us. Hot glue is used extensively in our flat foam models. We use hot glue to bond the control horns. This makes the job very fast and easy. Hot glue is also the choice glue when mounting the servos into the slots. All it takes is a drop on each tab. Using hot glue on the servos also allows for easy servicing. The glue can be reheated with the tip of the hot glue gun, or can be removed with care using an x-Acto.

Q:  Is a flat foam model good as a first airplane?
A:  Not in our opinion. We think a good first airplane would be a something like a Slow Stick. If you’ve flown a Slow Stick a hundred times and can do controlled aerobatics with one, then we believe you can comfortably fly a flat foam model. The good thing about flat foam models is that they are very durable and easy to fix. They can handle some pretty rough crashes and take off right away. If they do break, 5-minute epoxy will make them look brand new. Some of our experimental models at Atmocraft have crashed well over a dozen times and are still flying.

Q:  How do I get my plane to hover?
A:  This is a subject that everyone nowadays has on their lips: Hovering, the gravity-defying act that puts a plane motionless in the air, hanging on its prop. To successfully hover a plane takes two things: practice and the proper setup. The proper setup would be at least 1.5-1 thrust to weight ratio, large control surfaces and the correct placement of the CG.

Q:  What kind of servo do you recommend?
A:  GWS Pico servos are used in almost all our models. They weigh 6 g and give 12 oz of thrust. You want at least 10 oz for flat foam planes. Hitec 55 and 50 also work well. If you use one servo for both ailerons, select a 20+ oz servo.

Q:  Which speed controller should I use?
A:  The Castle creation 10 amp controller is very popular. However, the BEC in it is limited.  If you install servos that deliver more than 20 oz of thrust, use a 25 amp ESC.

Q:  How do I select a motor?
A:  With flat foam models you should go brushless. Higher thrust to weight ratios are achieved this way. Our favorite setup is the Himaxx 4100 fitted with a GWS D gearbox, swinging a 12x6 prop. This gives approximately 25 oz of thrust. Typical flat foam planes weigh between 11 and 14 oz. The battery to use is the Thunder Power 1300 pack. Etec 1200’s also work very well but are no longer distributed. This power system draws approximately 12 A at full throttle on the ground. In forward flight the current draw would be about 1 A less.

If you have more questions, or if you have comments about our answers to these questions, please email us.  Thanks.