Picture of A sketching machine out of a box
Should be SKETCHING, not drafting, as sketches are made for ANY type of drawing, drafting, you name it.
It's as easy as it gets, one cardboard box, some extra thick cardboard from another box, a mirror, and a piece of glass, or transparent acrylic.
Cut the cardboard, glue it, and you've made a Drawing Machine, with a 2-way glass, where you see the scene in front of you, and the paper where you draw!
Draw the lines, as drawing on a window, and you are both drawing, and gradually learning to imagine that same glass in front of any scene, one day.

Thanks for the rectification about drafting, rimar2000 :)
Also, Kiteman, here's the actual Illustration, from the 1923 "The boy mechanic" book available on the Net via Project Guttemberg.

Step 1: I assume you know how to draw a line...

Picture of I assume you know how to draw a line...
I assume you know how to draw a pair of 45º lines, using a 45º set-square, that you know how to cut Cardboard, and what diagonals are;
Because you have to cut a pair of these shapes, in order to glue them into the inside of the box.
d1ndian4 years ago
putting a magnifying glass would work even better
Edgar (author)  d1ndian4 years ago
Nope, it would complicate things a lot, you'd stop seeing all the scene.
rimar20004 years ago
Drafting, or drawing?
Edgar (author)  rimar20004 years ago
Both, actually, I'm sick of seeing Engineering geniuses that can't draw a 3D sketch to save their lives... :D
But it should be SKETCHING, as you can learn to sketch, both for drafting and drawing.
rimar2000 Edgar4 years ago
I have known professionals unable to string together a coherent sentence. The worst thing is that they fancy themselves with the right to teach an Eskimo to combat the cold!
Edgar (author)  rimar20004 years ago
That's what Instructables are for! LOL!
Kiteman4 years ago

The paper hangs inside the box, and you reach in somehow to draw over the projected image?

I think you need a wider shot of somebody actually using the device.

(If you've done what I think you've done, this is a version of a camera lucida. Or it might be a camera obscura with a hole in the side. I can't quite tell.

Edgar (author)  Kiteman4 years ago
Re-made the Instructable, so now, it's right in front of you guys, first picture.
Edgar (author)  Kiteman4 years ago
See this picture:

Kiteman Kiteman4 years ago