This is my first post, and I would like to say hello to everybody here. This looks like a neat community, and I'm glad that I found this site. I am new to CNC and am considering one of the C-Beam kits to get started. My requirements at this time are to be able to make machine parts out of 7075 aluminum alloy, and also to be able to engrave small text and pictograms accurately into 7075. I have some questions about the equipment to be able to do this. Is the C-Beam mill the right tool for the job? Is there a difference, other than the size of the substrate utilized, between the C-Beam and C-Beam XL? According to the C-Beam page, either a 12V or 24V power supply is needed. What factors are considered when deciding between the two? Also needed is a driver board. What are the considerations when selecting a driver board? Thanks in advance!
Define "machine parts". Cutting sheet goods and slightly thicker stock is doable but don't expect to be milling down 4" thick blocks. 1/4" bits are good to cutting down to about an inch and a half deep but even that at times may be pushing it. As far as the differences between the original C-Beam and the XL, there is roughly a year's worth of evolution between the two versions. If you look closely you'll note the Z-axis is turned 180 degrees with the whole beam moving up and down on the XL rather than just moving the router mount. The way the Z-axis mounts to the X-axis on the XL is also much stouter, something that is very relevant when milling aluminum. The Y-axis beams are also inverted to prevent debris from collecting in the channel. Personally if I were looking to build the smaller version, I would probably follow the methodology of the XL and distill down the parts list into the smaller unit. 12V or 24V? 24V gives the motors more power. Driver board: Cost and software are the major factors. If you are on a budget, the GRBL based boards are inexpensive and there is plenty of opensource/freeware to run them. If you're wanting something like Mach3 to run your system with you will need a parallel port based board. While these boards can be fairly inexpensive the cost of the software combined with the necessary stepper drivers can add up fairly quick. (Note: this is greatly generalized. If you need something deeper there is a whole section of the forum covering the subject.)
Thanks. I've been looking through the forum about info on boards and software, but most of what I've found seems to be Q&A for people already knowledgeable about the subject. Do you know of a guide that explains how these things work?
Really no guides that I am aware of. All I can suggest is posting examples of what you expect to be milling and let other users offer their thoughts on which software/board path would be most appropriate. Or you could just start with the arduino/GRBL route shown in many of the videos as it is not a major investment and if it proves to be insufficient, move up from there.
Everything Rick said is correct. another thing to think about is the current you are going to be delivering to the stepper motors. A lot of the grbl based control systems are good up to 2A. The Higher the current the better the stepper will work without loosing steps and have a higher holding force. This is generalized because it can go both ways with both type of systems. that all said you can cut steel on a c-beam using 2A drivers, but you won't be happy how long it takes. Cutting aluminum on a c-beam is no problem, plenty of us doing it. To answer your questions we need more information. Are you planning on this as a hobby cutting a part here and there? Are you planning on going in to production making parts 24/7? How big of things do you plan on cutting? on the regular c-beam I don't know the number off the top of my head but you can cut just under 1'x1'. Then you have the spindle, a smaller router or a spindle? what's best for you? All I can say is Have fun that's what it's all about!!! Bob
I plan on using the machine as a hobby, and making things infrequently. That being written, there are some very creative people in my house, who will likely commandeer the machine for projects once they see what it can do. =) I don't have specific or finished examples of what I want to make yet, at this point they are just ideas. One is a specialized vise, which will likely measure 4" X 2" X 1", being made of 7075 aluminum. This vise will have support beams for the material being clamped, and will be tapped with a steel screw for tension. I would also like to engrave into 7075 aluminum, which will need to be very clean and precise. Another example of something that I would like to make is a sort of "wiper", or ramp used to place pressure on small items as they are moving through a collator to be oriented properly. This can be made of something like delrin, or perhaps even printed. So...I really have all sorts of uses for a CNC, and if possible I'd like to be able to make all kinds of things, as I get ideas for projects randomly when I work on things in the garage or around the house.
For milling aluminum, the C-beam will offer better resolution than the Ox. Then it just comes down to which size. If you need the larger area, go with the C-beam XL. If not, as noted above I would probably follow the methodology of the XL just distill the parts list down to create a unit the same size of the original C-beam machine.
Entirely different style machines. But the main difference in your case is the shapeoko uses belt drive and the C-beam uses screw drive. Belt drives offer faster movement in trade for lower resolution and lesser cutting force. Great for cutting wood, foam, plastics, etc. Screw drives offer better resolution and higher cutting forces in exchange for slower movement. Great for cutting metal and will still cut softer materials just not as fast as a belted system.
reading what you plan on using a cnc for, I would recommend the c-beam machine. I would go for the xl sized machine, this has been upgraded from the original c-beam machine. go with 24v I like grbl, ie. free software.... good luck and have fun... Bob
