Wow..now i know how to sketch. Draw line, circle, arc or even free style sketch in paper. I confident  sketch any shape that a want..draw box. ahh kacang. Draw a Ball..ahhh lagi kacang. I can sketch clearly machine component and dimension it. From the sketch i made, i can use it to form a drawing technically drawn by drawing tools or even can built a model in a computer. So, even the technology right now using computer in everything but don’t forget the method that we use long long time ago. To produce engineering drawing previously, traditionally manually drawn using many tools ie. drawing board, compass etc. May be most of us familiar used this tools may be not. OK..just to remember, go here just to know what kind of equipment used to prepare Engineering drawing professionally.