CNC ECourse Day 5 CNC Control

CNC ECourse Day 5 CNC Control

Video Info:
Day 5 is all about CNC Control. CNC Control is made up of three parts. The CNC Control Computer, CNC Control Software and the actually CNC Controller. The CNC Control Computer can be basic and inexpensive. The computer will live in a harsh environment that includes dust and dirt. The CNC Control Software is what processes the G-Code program we made in the last step. You load it in and when you are ready, start the program. The actual CNC Controller has drivers in it and translates the signals from the control program into motion. It sends the signals on to stepper or servo motors that move the various axis All together these pieces can cost a lot or a little. You can also cut down the cost if you build the cnc controller yourself. Tomorrow we machine. This is where the chips fly.

Video Transcript:

Hello this is Ivan Irons and welcome to day five. Today we will go over CNC control and we will talk about what that is in a second. In the meantime if you have questions you can go to CNC information.com and get further information.

Again, here are the five different steps to the CNC process that we have been walking through. You'll see controlling down there at the bottom. Once were done with this, we will do machining and we will be at the end of our process.

We are on the controlling step and that's directing the machines motion and you'll see in this flow chart. What is CNC control? I think of it as three different things together: A control computer, control software, and a CNC we are going to need these different components. Sometimes they are combined together but if you build your own or have a commercial unit you will likely have these efforts separate.

We start out with a CNC control computer. This computer doesn't need to be the newest fastest thing. It's really only going to have one program on it and that's your control software. That control software will walk-through the G-Code that we made in our last video during the CAM process. That G-Code it is not too complex or sophisticated so you don't need a lot of brainpower in your computer. Also keep in mind that your control computer is going to be in a pretty rough and rugged environment. I think of my CNC plasma cutter, which puts out quite a bit of smoke and dust. That dust goes to the computer in some way shape or form. What I recommend is to go with something that's a lower cost unit that you really won't get to mad about when it gets damaged out in the shop.

Here's a look at my control computer for my CNC plasma cutter and it's actually a 486 Pentium so if you know anything about computers in was about the 1996 era and it has all the horsepower I need to run my G-Code programs. You can pick these up for 10 or 20 dollars or people give them to me and I have actually a stack of three of these at my house so if this one goes bad from plasma smoke and dust I have another on there. I don't concern myself too much about this control computer.

Next is Control Software and that software is what executes the G-Code programming blocks line by line. As we saw earlier, it goes through each of those steps and directs our machine. There are a bunch of different control programs on the market but I'm a huge fan of Mach 3 by Artisoft. It's kind of the organic control program that has grown over the last five or six years and has a huge community of supporters and people that help. I've also used TurboCNC and CNC Pro, the DOS versions of those, so just so you know there's a number of programs out there on the market.

Here's a look at the screenshots of Mach. This is about what your computers is going to look like when you have it fired up and load up the G-Code program and you start up the cycle. You will actually be able to watch it move around and actually in a few of my other CNC videos you've probably seen me use the software.

The third piece is the CNC controller. This controller processes the signal from the computer and the software. The software spits it out and goes out of the cable to a controller. The controller turns that signal into motion. There's a number of love different suppliers out there and you can also make these controllers as a do-it-yourself kit and they're really available in a number of different axes so you can have you to axes controller three or four-axis controller. If you do go out and buy a controller from a supplier most of those kits come with motors and cables as a part of the kit. Let me explain motors a little bit.

There are really two different types of motors that are used in CNC, those are Servo motors and stepper motors and there's a cost differential between the two. I won't go into it too much but incase you go out and buy a controller odds are it’s going to have everything that you need.

Let’s take a look at a controller that is on my CNC Wood router. I purchased this controller and like I said you can make these and there's a lot of people in CNC that this is the piece that they really like and enjoy. I’m not really an electronics guy, I’m more of a fabricator so any chance that I get that I can buy this lock stock and barrel from someone I do it. I spec these out in a certain way that I want a number of axes that I want. You can see the front there and then the rear where you plug in your cabling. This is an example of a controller.

Here you'll see a couple more: on the left of this is the controller that's on the side of my Bridgeport Mill it came with the mill when I purchased it as they a part of the entire package. On the right and that's older solid-state looking controller and that's really a combination that CNC control computer software and the controller all in one. Today they are broken apart little bit more but in the past when CNC was really just a production phenomenon this could be included altogether in one unit.

I thought I would briefly go over some cost so you have an idea in your head if you're going to put one of these together. The control computer costs are listed and I'd rather be on the zero end of that versus the thousand dollars but some people will spend the extra money to get the fastest thing possible. It is not needed in fact the vast majority of the time. You can buy a computer secondhand at a garage sale and it will work out great.

The control software costs are like any software, there's a free one out there and there's a high-end one. I think I got my mock3 for like $150 and I may have bought it in a package with sheetcam. I think it was around on $150 for that.

The controller that's where you are going to spend your money and like I said before it really depends on the number of axes that you select. You can also think of it as smaller motors for something that doesn't really need a lot of force to move around for example a plasma cutter can have smaller steppers or servos because it's not like you have any side loading or side force like you do in a router. Then if you get into a fourth axis when you buy it from someone and you have big steppers and servos that come with it you can easily be in the $5,000 range without trying. That’s a look at the different costs.

Tomorrow we go into CNC machining so we will use our controllers and run our G-Code and talk about the true machining process. CNC machining is very similar to regular machining but is controlled by computer. In the meantime if you have any questions at all feel free to go to my website at www.cncinformation.com.