Mark K's CNC Machine
A quote from Mark, "You have really given me a lot of confidence with your web site and your book to help me build my CNC. I never dreamed I could afford to have one let alone build it myself. I am actually a shop (industrial tech) teacher and have built it for use in our shop. I am very excited to see what I and my students can do with it. I also wanted to point out that in you book you said you wanted to present the material at a level that an 8th grade student could understand. I definitely think that I could help students build a CNC machine using your book and videos as a reference if I were allowed to hand pick the students. you have done an excellent job explaining, demonstrating and providing sources for parts."
It is quite evident that Mark has a sense of design and aesthetics with the way he modified his CNC Machine. As is obvious, the machine that I designed has many areas that are not necessary. The parts were designed to make it very easy to build the machine by hand. Mark obviously noticed these unnecessary areas and decided to produce a machine that literally cut corners. The resulting design is very attractive.
The first and most obvious change that Mark made is on the gantry sides. He totally removed the top superfluous area and then added a large chamfer to both edges and rounded out the corners of the chamfer. The Screws appear more centered and the overall gantry side has a much more streamlined look. A perfect elevation was not provided, but I'll bet that if the point of view is towards the gantry side, the aluminum angle pointing above the top would appear very harmonious with the gantry side.
The next obvious change was made to the router mount sides. Again, the superfluous area was removed for a much more streamlined look. You might be wondering, what about the rigidity and structure of these parts. Mark kept most of the material and the material that was cut, was overkill.
Mark also produced an example. I note this image because the routing is exceptional. The inside corners of the text (mainly in the serifs) are very sharp. The only way, that I know, to do this is to use a drill mill, v-groove bit, or an engraving bit.
A discussion on how much material that should be removed for design enhancement: It is my hope that others try similar approaches in design like Mark has. Here are a few rules of thumb to remember. The material that should be kept in this design should have a couple factors of resistance to the forces that are applied on the machine on a regular basis. The load on the end mill is the main force that should be considered in making modifications to the machine. If too much material is removed, there is a possibility that the machine will flex too much. One example would be too much modification to the gantry side. If the gantry side was thinned, or the race was necked down below the screws for the horizontal connection, the gantry would potentially cause a twisting of the y-axis rails. Enhancement can also come in the form of adding material where it would make sense to provide more rigidity, especially if the machine's size is changed (larger).
As you read above, Mark is an industrial shop teacher and below are some of the projects that Mark's students did on the CNC Machine.