The wing needs to be properly positioned on the model to ensure the model will fly correctly. The plans show that the balance point of the model needs to be about .7" (17.8mm) in front of the trailing edge of the model. This balance point is with the model assembled and WITH a 2 gram rubber motor. If you balance the model without the motor then the actual balance point will be much different and will cause erratic flying and difficulty in trimming.

The first thing we will need to do is make up a 2 gram motor. This is easily done by tying up a 11" loop of 1/8" rubber. If you do not have 1/8" rubber than a loop of 3/32" rubber about 14.5" will work as well.

Place the prop assembly on the front of the motorstick/tail assembly.

Attach the rubber to the prop and to the rear hook. Then use a bamboo skewer stick or a piece of wire and slide it between the motor and body. Move the stick forward or backwards to find the balance point of the model.

The model is balanced when the motorstick is horizontal.

Once it is balanced, then mark this location on the body with a pen or felt tipped marker.

Now we have to determine the exact location of the wing. Because the covered wing weighs so much, mounting the trailing edge of the wing .7" behind this mark will actually place the cg too far forward. The reason being that the weight of the wing is in front of the marked balance point, and the extra weight will require the marked balance point to move forward towards the wing. How much it moves depends on how much the wing weighs. I have come up with a little table to give you this distance based on the weight of the covered wing.
 
Wing weight in grams Distance in
inches		 Distance* in mm
1.50 .26 6.6
2.00 .33 8.4
2.50 .40 10.2
* if you have a Division C model than you must add and additional 0.15" (3.8mm) to compensate for the landing gear weight. Example: 2.00 gram wing = .33 + .15 = .48" ( 8.4mm + 3.8mm = 12.2mm )
Use this table to determine the distance we need to measure in front of the mark on the body. If you do not know the weight of your wing than I would use 5/16" because 2 grams is a very typical weight of a wing.

Make a mark on the wing 0.7" (17.8mm) from the trailing edge of the wing. This is where the balance point should be.

Now line up the mark on the wing with the new mark on the body as shown in the picture below.
You can gently pin the wing to the body to help hold it in place while you do this if needed.

Take a pen and mark the trailing edge of the wing.

Now do the same thing for the leading edge of the wing.

Continue on and attach the wingposts to the body or go back to the main page.