Appropriate rubber mass

[Bitconnect]

As known, there is no limit on rubber mass this year. I have been using 2-gram loops of varying thicknesses and can normally get around 1:50 ish times. I was wondering how much more mass I can add to my rubber loops until the mass outweighs the benefits in winds.

[coachchuckaahs]

And that is the crux of the development and experimentation this year!

This will depend on your plane design and trim, your ceiling height, your prop design, etc. While everyone may have a slightly different optimum, trends will be similar. As you change mass, you will want to change thickness as well. One good method would be to set a target mass, in your example, 2g, then vary width (and length) at that mass to get optimum for your plane and prop. then select another mass and do the same. Keep accurate records, and an optimum should begin to unfold.

Of course, this will take a good supply of rubber! With the greater number of variables this year, expect to make a LOT of rubber loops to find your best combination.

Note: Another thing you can do the ballpark is to add some mass at the CG while using your current rubber. As you add mass, you will need to go thicker. To do this right, you would add mass to a stick that replaces rubber. In other words, lets say you have a 2g rubber, and want to simulate 4g. Make a stick that is 1/2 the length of your hook-to-hook, and add clay to the center of the stick to make it 2g as well. To simulate 3g, make the stick 1/3 the length of your hook-to-hook, and ballast the stick to 1g. Scale the altitude and the time (2X in the first case, 1.5x in the second). It is easier to scope things out with clay on the CG and no stick, but not as accurate because the full rubber you are representing with clay will be stretched differently. But, it will rapidly give you an idea of how the plane/prop performs at higher mass.

Coach Chuck