The scale factor is roughly X2. The tube at the rear is 100mm millimeters in diameter and 130 millimetrs long. The smaller tube is 48mm in diameter and runs though the entire lenghth to the nose cone about 760 millimeters (or 30 inches) the nose cone adds another 90 millimeters (or 3 1/2 inches). I hoping to add some scale markers to my drawings. To help other people duplicate my templates. I used Sturdy Board for the fins. and the canopy and nose cone was printed directly on to 110 Cardstock paper then cut out. I know alot of you guys take things more seriosly with Balsa and stuff, but it gets harder for the average joe to find these days. I needed to comb three different Hardware chains to find anybody who stocks it. Some day I'll make or find a good CNC mill to cut my Fins for me. Like an old table plotter with the pen tip switched for a drummel tool. Oh to dream. As for the motor I haven't made the mount yet. Since I'm not party to a real rocket club I'm stuck with D's to power my rocket. I made a fairly large ATD rocket a few years ago an it got some good altitude with a single D so I'll just stick to it for now.