That sounds familiar 'DD'...I had this problem before, but obviously cant remember how I solved it.
In the end I cheated by increasing the scale on print menu to 132% to give me the required 42"
And for those of an 'inquisitive' nature....its a tank!
A 1/6th scale Tiger tank to be exact, scratch built of course, no way I can affor the gorgeous ArmorTek offerings, I planned to build this in the garden over the summer, what summer I hear you mock.....exactly...what summer?
I'll do some pics as & when get something worth piccing, and of course there will be more on my own site too.