By the experience I have accumulated, especially in designs like this, that certainly is going to have to evolve, change, and adapt to different conditions according I discovered more things, it is essential to draw so that design changes affecting the lowest possible number of pieces.
Let me explain. If for example, we designed the machine almost completely, and suddenly discovered that the type of profile that we would use to reinforce the structure is not available, and based on these measures we have designed a lot of elements, and now, What can we do? If we have to go part by part searching for changes we have a problem. Because it is probably that we will have some dimension wrong, or some change that we forget, and finally producing a design error.
Therefore, and after many failures like this, I have learned a very useful technique: Base the design on a parameterized CAD design, or adaptive. This works as follows:
The first is to create a piece in which the main lines and dimensions, a sort of outline or skeleton of the entire structure or the main dimensions of the most important parts. I will update this file while I’m drawing, ie, you cannot have clear the design from the beggining.
Second, decide how to structure the files, select a hierarchy of parts and assemblies in a coherent way, so that the different units do not overlap.
Third: Design! We started designing the different parts, but do not place a dimension on design. In the assembly we are working in, the first part to insert is the skeleton we have drawn. And we create the rest of parts around this one. This is an easy way to organize, and at the same time, when we have to change any dimension, just have to change the original part. Supposedly the rest is modified and adapted saving us work and errors.
Will not explain every single step I followed to design everything, because it would be a hard job, but I’ll summarize the key pieces to make a general idea of the design. Other important point is able to design according to the resources that are available. Fortunately, I can have a lathe, Milling Drill-and a pretty good machine shop equipped with drills, end mills, inserts for lathe tools, hand drills, etc …. Throughout the project I will mention the tools they’ve been using.