Beginners Guide to Manual & CNC Machining!

Hi folks, welcome to another episode of NYC CNC. This video is for the Concord kids. They're a group of students that are focused on the STEM curriculum and their advisor shot me an email and said some of the stuff that they're working on it would be really helpful if they had a video that would show them some of the basics of what a milling machine does. And this really struck a nerve with me because coincidentally I was just talking to a local Ohio area um overview he's a he's responsible for all of the trades curriculums and they have a huge interest in the welding program they can't get kids interested in machining which baffles me and i think part of it is because welding is big in central ohio with a lot of the oil and gas and people think if there are welders they get to drive big trucks and get muddy and go to job sites and hey that's that's cool to people i totally get it but but to think that they're choosing that because they don't even know what machining is. They have no idea. And hey, I was there once too. I didn't grow up, my grandfather's a steel fabricator. I didn't grow up with bridge ports and milling machines and so forth. So I get it. So I would love to make this little video and show people what metal cutting and machining is. What I want to do today, two really basic things. We're going to show some test cuts on a piece of aluminum with a Bridgeport milling machine. This mill is probably 50 years old, but it runs great. And then what we'll do is we'll move over and we'll take similar type of cuts on the Tormach CNC machine, which is a computerized version of basically the same thing. This is our Bridgeport milling machine. It's kind of like a drill press, but a lot more. It's similar to a drill press in that we've got a handle that raises and lowers a tool in the quill. But if you'll notice, this quill is really fat and it's actually really strong compared to a bench top type drill press. But what makes the machine really different from say just a drill press is we've got these handles and I can rotate these handles and move the table left to right or the x-axis and then I can use the handle in the front here and move the table back and forth or front to back in the y-axis. So not only can we cut down like you do with a drill bit but we can use an end mill just like that's in here right now and cut on the side of a piece of solid metal just like that. There's a ton more than this machine you can actually do but that's really the essence of what we need it to do and that's what we're going to take a look at today. So not only does the machine have to be really strong and really rigid but to be useful it's got to be accurate. Accuracy is just key in metalworking and machining and for this machine which remember it's like 50 years old we can still do that. The key are the graduated dials on the handles. We can use these dials to accurately machine and measure distances in 1,000th of an increment measurements. And if that doesn't sound precise to you, 1,000th of an inch. That's crazy. A sheet of printer paper is 4,000th of an inch. Let's take a look at that accuracy. Our dial here is on zero. We'll go ahead and rotate it. I'll do it slowly for the camera to 20,000th. So that's about five sheets of paper that we should be moving the machine in. Enough talking, let's see this thing in action. Safety glasses on, folks. What we'll do is we'll slide the workpiece under our end mill. We're going to use a two flute, pretty large diameter end mill, and we'll just go ahead and move the quill down to right on top of the workpiece. That locks the quill in place. I'll come off the workpiece and I can actually lift the table up just a hair. We'll turn her on And let's see if we can face off the top of this part. It's nice and easy. We'll come over, and you should see we're making a nice chip. Machine doesn't sound too loud. And because this workpiece is at a little bit of an angle, we'll probably run out, as you see right there. So, okay, we'll come back, and we'll just keep cleaning it up. You can go a little faster if you want. Again, folks, we're cutting through metal right now. I think it's pretty cool. You want to try to be smooth with your motion. That'll make for a better cut. Come back right over here. looks like that's all will get removed at this height if you will. We'll stop the machine and if you feel that it is silky smooth and that's what's really cool. It's a really nice quality cut. So that was cool. We sort of cut the top of it. Let's see if we can do a little bit of a heavier cut and let's actually see if we can measure the accuracy. So we're going to unlock the quill, lower the tool down and now what we're going to do is we're going to take a little bit of a cut off this one side. Then we'll use our dials and our digital readout to measure how far over we cut, and let's see if we measure the part that we end up with and see if we were accurate. So here we go. Fire her up. Pretty cool. You can see the chips flying off that machine. Should be a nice surface finish. It sounds good. You don't hear chatter. Real nice cut. Nice and steady. Let's take a look at that. Beautiful. I like that. Let's take a side cut now and see if we can clean up the side of this part and then move over we'll measure how far we move and we'll see if that distance makes sense and is accurate this is a two flute quarter inch end mill let's fire up nice and smooth look at that great surface finish very happy with that now we'll come back and we cut that at zero on our dial so let's move all the way over and if we cut it at two. We'll see if that makes sense. Now that's a little bit too much for me to take in one pass. So we'll lift up the quill and we'll take a little bit of a shallower pass at first and we'll do a few more deeper. Nice and easy. Come down a little more. You could also come up with the knee. Either way works. So let's use our digital calipers, which is sort of like a tape measure, but pretty accurate. Let's see what we got. I'm going to fit them in here. We're at 1.75 inches. So let's think here. Does that make sense? Well, at first you would think, no, I thought we went from zero to two inches. But if you think about it, when we were cutting on the left side, we were at zero. But remember, we're using a quarter inch end mill. So zero is the center line or the middle of the tool. So it was cutting one eighth of an inch or 0.125 off on the left. Then we moved over to the right. We cut another quarter, eighth of an inch or 0.125. So in the end, We've removed 0.25, so we went from 0 to 2, but we back out that tool diameter, 1.75, folks. Pretty cool, huh? Here is a CNC milling machine, and believe it or not, it's actually incredibly similar to the Bridgeport we just used. The difference is that instead of using a hand and cranking those knobs, we've got motors, and they're driven by computers, which take G-code that we sort of program in, And it's those computerized motors that move the machine back and forth, which is really cool because you can end up with a very easy way to automate the cutting as well as create complex cuts. And if you want to watch a really good video, in my opinion, on a basic way to build and understand, I just did one where I used an Arduino and a very inexpensive shield called a GRBL shield. And we built from nothing a pen plotter that we used to use a pen and create a pattern. It's pretty cool stuff, folks, and it's really not expensive to get into. So this machine, again, it's just like the Bridgeport. Underneath here, we've got screws and motors, and that drive the table back and forth. And we can use the computer keyboard. We can go left, we can go right, we can go backward and away from us, and we can go down, and we can come back up. Now, that was me controlling it myself. I've got a little program in here, and what it's going to do is it's going to trim this block. Sort of like what the Bridgeport did and we'll measure it afterwards and see what it looks like and then it's also going to Create a circular pattern in the middle and that's something that would be a lot harder to do if you didn't have a machine That could calculate and control the steppers with such precision Okay, so the spindle starts up it approaches the side of the part here You'll hear the coolant kick on, those two gray lines have coolant and you notice when it didn't just jab itself into the part with a nice smooth ramp in coming along you can see the chips flying off looks really nice the reason that end mill is coated is it's a special coating different coatings for different materials that help improve the cut quality or tool life, lots of really cool things like that again though it's all being driven by the computer here and the motors that you see under that are underneath this machine should be pretty darn accurate the proof will be in the pudding we'll have to measure it here when it's done Just about coming down home stretch, and if you watch closely, again, it's gonna ramp out It'll take a nice little curve right about now which hopefully will mean there's no tool mark where the part started and finished. Now we're gonna cut a circle and instead of plunging straight down into it, you'll notice it did a little, it's called an interpolation but think of it like a curlicue type of slide and that really reduces the chip load It's a lot easier on the machine and the tool nice and easy going into the part like that And if you think about it, it's cutting a circle like this is using both of the X and the Y axis at the same time And that's what's let us cut a perfect circle like this, which, again is something that would be a lot harder to do on the Bridgeport but it's quite easy on a CNC There we have it. Let's grab our calipers, and let's see if we really got what we hope here. Look at that, folks. 2.249 we're about one thousandth under so across that whole distance we're less than one quarter the thickness of a piece of paper off i'll take that any day folks i hope everybody enjoyed that really brief episode of NYC CNC and sort of basics on both manual and how a CNC machine works for those of you regular subscribers i know this was really basic but i'm really hoping to help and encourage anyone involved with STEM or any sort of youth engineering and science and technology It really is so cool. I would encourage you to reach out to either your local STEM program or FIRST Robotics or anything you can do because I tell you, the world needs more engineers and scientists and metal workers and stuff like that. To the Concord kids, I hope you enjoyed this video. I hope it helped you learn and understand the types of equipment out there. A lot of it isn't expensive anymore. That's what's really cool. I did a video about buying this Bridgeport, which I bought for less than $2,000. I know that sounds like a lot, but it also produces money. It's not a huge investment. some really cool opportunities out there i certainly have loved being a machinist and being able what i being able to do what i love in this career and field and the more we can help people understand and see what's out there and enable them the better off we are so thanks for watching i'll see you this wednesday for the wednesday widget otherwise take care see you soon thanks folks