A basic model aircraft balancer by Tom Laird. 7/9/2001

Price

2 ish

Construction

Mostly wooden contruction with some perspex.


Notes on buying a model aircraft balancer

It is a fairly safe assumption that if your model is not balanced properly when on the ground, it ain't going to fly very well when it is in the air. Please do not assume that because you have just bought and built an ARTF model, it will be okay - it probably will not be (see the article on the Ripmax Nova for instance).

The Build
This little excercise should be within the scope of most people. First, go to your local D.I.Y. superstore and buy a length of 1/4 inch diameter round dowel. Cut it into two 12" lengths. Round one end of it into a dome shape.

Find or buy a piece of wood approx 18 inches x 6inches x 1inch thick. Drill two 1/4inch holes in the wood, approx 8 inches appart. Put the two dowels into the holes (round end up).

Stick a piece of masking tape to the bottom of the wing, mark the distance in to the centre of gravity, and carefully place the model on the sticks. Move the engine on the engine mount, and move the battery until the nose of the model is pointing slightly down. You might have to add ballast (lead) to achieve this. All this is better done with a helper, and be carefull to make sure the sticks are on the sheeted area of the wing otherwise they will go straight through the covering.

(Click on the pictures to bring up a larger image)

   
This picture shows the deluxe version upgrade. Two perspex rulers with dowel glued to the end allow the centre-of-gravity position to be pre-set. The rulers slide in two balsa guides.
If you want the professional version all you need is a couple of brass / plastic ball joints (these ones came from Scoonie Hobbies). Cut off the leg part, clean it up, then epoxy into a round servo arm.

Take the afore-mentioned 1/4 inch dowel and instead of sanding the end to a dome shape, drill a hole into the end. Drop in some cyno the push in the brass ball joint. Hey Presto! a balancer that gives better performance and spreads the load on the underside of the wing due to the larger area of the servo arm. A bit of foam or rubber can be added to the servo arm to give better grip.

 

 

The Summary
An excellent piece of kit at a reasonable price. Easy and quick to make, and takes away some of those first flight worries.