A quick demo on what you can use Al.Chemy for. It is more of a sketching/ thumbnailing program used to generate shapes. Its another way of brainstorming and designing that lends itself well for mechanical things. Usually I will try to generate a number of interesting looking elements and then take them to photoshop where I rearrange them and piece them like a jigsaw and cut out parts I dont like. Then you can use the shape as a mask and paint into it!