...For the project I have started, I was enlarging the plan from a 24'' wingspan to a 36'' wingspan (50% enlargement). I imported the tileprint plan into CAD, enlarged it and started converting to CAD. I realize the materials would need adjusting dimensionally, but the fuselage just looks HUGE dimensionally for a 1/2A plane (6'' tall and over 4'' wide at the wing saddles)! It would probably turn out grossly overweight if I did it this way. Also, I wasn't sure if the control surfaces scaled proportionally to wing area/span...
Ah, now the picture is a little more clear.
You're running into the whole issue of gear size vs model size. On larger models it's almost never an issue. But when you scale up a 24 inch span model you run into the simple fact that the radio gear needed X amount of volume to contain it. And now you're blowing the design up to Y. But you end up with this great big cavernous opening for the gear.
That's where the whole thing falls apart to some extent...... Now you're faced with either finding an alternative structural method to hold the weight in check or you need to consider re-designing the model to make the fuselage more skinny.
There IS another option. The 1/2A page has plans or links to plans for a couple of models in this size range that are proven flyers. Two in particular are the LST (Lynn Sipes Trainer) and the shoulder wing stik style design named "Das Not Ugly". There's also some great old classic plans that can be downloaded from Dave Fritzke's website at http://my.pclink.com/~dfritzke/
. Any number of those would suit your needs. The Jr Falcon and Jr Skylark in particular are easily adapted to ailerons, if that is your desire, by halving the dihedral and adding a sub trailing edge to allow the original size of trailing edge to be used as strip ailerons.