Step 17: Back to the drawing board
- Measure your machine size
- Find your home point
It's important that the lines are all square and parallel, and your measurements are accurate. You can't hope to get good results if you don't have it marked out properly. As they say: Proper Preparation Prevents Poor Polargraphs. Don't they?
Ok, so measure your machine width, in mm. This is the distance between the closest points of your sprockets. Measure from the teeth rather than from the rim. It should really be from the point where the cord hangs, but that changes all the time, so this'll do.
Now draw a line for the top edge of your machine. It should run exactly in between your sprockets, between the two motor shafts.
Draw another horizontal line, exactly 120mm lower than your top edge you just drew. This is where you'll put the top edge of your page. You can't expect to draw much higher than this.
Draw a vertical line down the exact centre of your machine. Where this vertical line crosses your top edge of page line is your home point. The machine knows where it is, you know where it is. You both agree, and it's where everything starts from.