Scaling up a model has very serious structural implications. If you make every thing X times as big, using the same materials, the strength of any structural element goes up as X squared which is the crossectional area increase of the structural element's crossection. The forces go up as the volume of the structural element, which is proportional to X cubed. Therefore the strength to weight ratio declines in proportion to 1/X.

For example, take a 1/4 by 1/2 spruce longeron 48 inches long. It has a crossectional area of 1/8 of a square inch and a strength in compression of 701 pounds. It has a volume of 6 cubic inches and weighs about 1.4 ounces.
If you scale up the structure by a factor of three, the new spruce longeron would be 3/4 by 1-1/2 by 12 feet long. Its strength in compression would be 6311 pounds but it would weigh 37.8 ounces and its strength to weight ratio would be only 1/3 that of the model's longeron. This means that the empty wing loading of the larger aircraft would be three times greater than the model and the relative strength only one third of the model.

If the original empty weight of the model was 30 pounds then the empty weight of the larger aircraft would be about 810 pounds. Add the weight of the pilot and the gross weight would be about 1000 pounds. To be able to generate the lift necessary, the larger plane would have to fly almost twice as fast as the model. The kenetic energy involved is proportional to the square of the speed and would be almost four times as great as with the model. So you would have a structure that is only 1/3 the strength to weight ratio trying to absorb four times the energy in say a hard landing. The larger plane would be much, much more fragile than the model. If you were scaling up the structure by a factor of four or more, the situation would be much, much worse.

The point is that you can't scale up a structure that much and get away with it. You would have to redesign the structure.