Click here for episode
Welcome to the first episode of the You Create Podcast. My name is Erick, and I will be your host each week. The You Create Podcast was created to explore the maker in all of us. Everyone has ideas that they wish to create; however, that’s usually where it ends for most people because they don’t have the knowledge or the equipment to turn their ideas into reality. This podcast will break through that barrier and will cover hundreds of ways so you could start making ideas come true through the use of CNC and 3D printing technology. Now, don’t let these terms scare you because my goal is to make this entire process fun and easy.
I want to start off with full disclosure and let you know that this podcast is sponsored by Stepcraft and some of the content will be based around things that you could do with Stepcraft machines. Due to the universal nature of Stepcraft and the ability to perform many different functions with the same machine, this system is the perfect solution for those who wish to create things out of wood, plastic, foam, paper and even aluminium. If you don’t own a Stepcraft machine, that’s okay, after listening to a few episodes of this podcast I’m sure you are going to want to get one. For those of you who own a machine other than a Stepcraft, fear not, this podcast will be equally useful and informative to you as well. The ideas as well as the tips and tricks that we talk about in this podcast will be applied on any CNC platform and while we may talk about some specific items that relate to Stepcraft in certain episodes, the bulk of the content is designed to be very universal.
One common goal that many Stepcraft customers have is the desire to create things that they can sell. Some want to create items that they can sell one-off versions of on websites like Etsy, while others are looking to create a full-blown business to sell items that they produce every day.
My personal background is in business development, marketing, website development and sales, and because of this I will share the many concepts with you that I have learned over the years and hopefully will be able to help you in your goal in starting a business if that is what you are looking to do.
With all that being said, I want to welcome you to the first episode. Let’s get started.
Since this is a new podcast, I am going to assume that many listeners are new to this technology. For those of you who are more advanced, I apologize as this will be a little bit of a beginner theory that you would already know. I want to start off by discussing a little bit about what we mean by the term CNC. CNC stands for Computer Numerical Control. That doesn’t really say a lot, I guess but at least you know from the definition that it involves a computer so there are no surprises there. A CNC system will take something that you create, design or draw on a computer and will turn it into machine code that tells the CNC machine how to move and make your part. Think of it kind of… like an inkjet printer but rather than an output on the paper, the output is in the form of a 3-dimensional part.
Throughout this podcast we are going to talk about a couple of different types of CNC machines. One in particular that we are going to focus on initially is the CNC router which could also be referred to as a mill or a carving machine. The other type of CNC machine that we are going to spend some time talking about as well is a 3D printer. Both machines are considered CNC and they both use a drawing program that converts to machine code which tells the machine to move in three axes; however, milling and CNC routing is considered a subtractive technology in that you are removing material from a base piece such as wood to create a finished part where 3D printing is an additive technology where you are applying layers of plastic to create a part potentially from nothing. So, in this first episode we are going to talk a little bit more about the CNC router (and that kind of machine) and in future episodes we will certainly discuss a lot with regard to 3D printing as well.
As I mentioned before, a CNC moves among three separate axes; we refer to those as an X, a Y and a Z. The X axis is when you look at the machine from the front, so that would be moving the head or the tool of the machine from the left to the right – so that would be referred to as the X axis. The Y axis is when you move the machine from the front to the back and the Z axis is when you move the head or the tool up and down. So, those are the three main movements that you are going to hear us talk a lot about on future episodes and it is important that you know what’s X, Y and Z, especially when we are referring to different software and we talk about zeroing out a part, you are going to need to know what we mean by that.
To move the machine along these three axes we are using three separate motors. The type of motor used in a CNC machine is commonly referred to as a Stepper Motor. It is an encoded motor that every time it makes a movement it is referred to as a step and the distance varies from motor to motor. The software knows exactly how much that motor has moved, so typical AC or DC motor, when you turn it on and apply power it just starts spinning and when you turn it off inertia will make it continue to spin a little bit until the motor shuts down; but there is no encoding so you don’t know exactly how many RPMs or how much that motor has moved. A Stepper motor on the other hand, takes pulses from a controller and it moves these motors very, very, very specifically to acquire the movement that you need to control the head on the CNC machine. They move extremely fast and they are very, very precise. It is not uncommon that most CNC machines will hold the tolerance of a thousandth of an inch or better, so you don’t need to know a lot about the technology but it is important to recognize that they are not standard motors and when you are working on a CNC machine and you are doing maintenance or assembling one from a kit, to make the motors more precise, it helps when you assemble the machine to make sure that all the moving parts are properly lubricated. If there is any friction then that could cause the motor to do what we call lose steps and that will provide very undesirable results when you are either 3D printing or milling. So, we will talk a lot more in the future episodes about maintaining your machine but I wanted to get out of the way some of the basic parts of CNC machine early on so that as we refer to them in future episodes you know what we are talking about.
In addition to the motors there are some other major parts of CNC routers specifically or CNC mill machine that I want to discuss with you and make sure that you understand what we are talking about when we mention them. The first main part on most CNC machines is what we call a Gantry. A gantry is probably the largest moving mass on a CNC machine and it controls the Y axis (front to back) and has the X axis motor and assembly as well as the Z axis mounted on it; so it is a pretty important part. A most important thing to be aware of when the gantry is in it, is when you look at buying a CNC machine you want to make sure that this is an extremely solid and rigid component on the machine. When you think about it the gantry is holding the spindle (which we will talk about in a minute) which is also holding the tool, and if there is any flexing at all in the gantry unit, that gets transferred directly to the tool, which will have an effect on the quality of the finished part. This is especially true if you are carving, where you have got a lot of intricate details, the rigidity of the gantry is going to provide you with a better final part. The gantry will also determine the maximum workable height of your part. Usually, it is a specific distance up which controls your Z travel and depending on what applications you are going to use, you need to keep this in mind when you are considering purchasing a CNC machine. You would want to make sure that you have enough Z height travel and that the gantry is large enough to accommodate the thickness of the part that you are going to run or the base stock. It is also important to know that a lot of people have misconceptions about this where they will be convinced that they need to have a Z height that is 8 – 10 inches tall; however, even though your Z may move that high, at the end of the spindle there is a tool and you are not ever going to take use of the entire thickness of that part because the tool is usually only 2 or 3 inches tall max. So it’s a little bit of a misconception that you need to have a super tall Z height on your machine so you really need to just consider (I would think) something that is between 3 and 6 inches is probably going to take care of 90% of the applications out there for most people who would be listening to this podcast.
Now, the gantry also as I mentioned, holds what is called the Spindle. The spindle can be a router such as a trim router…like from a Dewalt Bosch or Makita, it could be a hand tool such as a Dremel or a Proxxon and the machine would have an adapter to hold those tools or it could be something proprietary, for instance on a Stepcraft system there is an HF500 which is their high frequency or high speed spindle that’s proprietary to the Stepcraft machine. So, you could use a Dremel, Dewalt or proprietary spindle but the job of the spindle is to spin the tool that will cut away the material. Some things to keep in mind there depending on the type of material that you are planning on working with, you want to make sure that you have a spindle that’s adequate in terms of power and you also want to consider the length of run time that it’s going to take to produce some of your mill parts and make sure that you have a spindle that is capable of running for that duration without burning up the motors or the bearings on it. As an example, a Dremel tool works great on a lot of CNC systems. We have an adapter through Stepcraft that will allow you to use the Dremel with no problem; however, the Dremel is not something that you would use successfully on a milling job or carving job that might take 2 to 3 hours to produce. It is just not designed to run for that long under load. Trim routers such as the Dewalt Bosch, and the Makitas are a little bit `beefier’, they have a lot more power, they are better for maybe taking out deeper passes on harder materials like hard wood or plastics. Usually though, the proprietary spindle is going to cost the most; however, it is going to have the most power and it is going to be designed to run for long periods of time under load. A proprietary spindle is also going to have the ability to adjust the RPM in the actual G-code of the software that you are going to use. So, if it was a specific material you may want to run at 8000 RPM, you can actual assign that in the software and the spindle will work at that RPM, whereas a router such as a Dewalt or the Dremel tool you have to manually control the spindle speed and it’s not controlled by the software. Additionally, the powering on and off of the spindle on a proprietary system is also taken care of by the software, some machines however, will have some kind of a power supply that you would plug a Dremer or a Dewalt into that will shut on and off based on code in the software so that the spindle can go on and off without you having to manually do it. That is not common in most machines, you will have to do it manually.
If I was looking mill parts out of aluminium, I would not be using Dremel because the Dremel’s just not designed to take that kind of a load unless you were taking very, very thin passes at very slow speeds. So, if milling aluminium is something that you were considering, then you really need to be looking at a more proprietary spindle that has a lot of power, has the bearings and is designed to work under longer strains.
In addition to the spindle and the gantry, the gantry and all of the movements ride along what is called the Rail system. The X, Y and Z axes all have some sort of rails and these could be made with slide bearings, sometimes there is a track that has bearings on it. The Stepcraft machine uses an extruded aluminium material that creates a track and we have our own specialized track rollers that we use with bearings that provide an extremely smooth and rigid movement on all axes. Usually the rail system, the gantry and the different moving parts are controlled by (obviously) a Stepper motor but some use belts that would go from the motor to the moving part, some use threaded rods, some use ball screws, there are various different ways of doing it. The most reliable in my opinion, is using a threaded shaft or ball screw. Basically, it is like a screw and a Stepper motor will move a specific amount and given the screw, that’s going to cause that axis to move a specific amount according to that. So, you tend to have the most precise movements on a CNC router when you are using some sort of a screw or ball screw-type mechanism for moving the rail.
Another major component is called the Bed and obviously, that is the part of the CNC system where you are going to put the material that you are working on. Typically, beds are made from wood or aluminium. Wood is usually a MDF* material because it tends to be very flat, it is inexpensive and there is no warping usually with MDF. On most jobs that you are going to mill, you are always going to have a spoil board which is basically a piece of wood that you are going to put underneath the part you are machining so that when the bit passes through the part, it can go into the spoil board and you are not going to ruin the actual bed of your machine. For some CNC machines, the bed is actually made of MDF and it is also considered to be a spoil board, so after so many times of use you are going to have all kinds of lines in it from the bit passing through the part and you will either sand those down or you will replace the MDF and make a new board.
Other machines would use what is called a T-slot table which is usually made out of aluminium. Stepcraft has both. We have a wood…which is (kind of) like a formica-covered board that you would put down and that is designed for some of the applications that we have on the Stepcraft machine that involves a drag knife and things like that. If you are milling on top of that board, you are always going to use an eighth or a quarter-inch piece of ply wood or something to use as a spoil board.
Now, a T-slot table is a little bit different. There are channels milled in the table itself that allow you to put nuts with bolts to anchor your work piece down. If you are milling with a T-slot table you definitely always want to make sure you have a spoil board because if your bit were to pass through your finished part, you don’t want it to bury itself and mar up a perfectly good and oftentimes expensive T-slot table.
Those are some of the basics as far as different bed types that are available depending on different machines that are on the market.
We talked about the spindle which is oftentimes also referred to as a router. There are two other components that have relation to the spindle itself: one of them is called a Collet, the other is the Tool.
*MDF – Medium Density Fibreboard.
A collet is a compression-type holder that fits inside the bottom of the spindle. It is the part that spins and there is usually a knot on there to hold the tool in place. Collets are made in various sizes, you can get them in 1/8th-inch, 1/16th, 1/4, 3/16th – all kinds of metric sizes. The idea is, depending on the shank diameter of the tool, you are going to want to make sure you have a collet that matches that. If, for instance, we are using a 1/8th inch diameter tool, we use a 1/8th-inch collet and when you put the tool inside the collet and you tighten the nut the collet itself compresses all the way around it on all sides and it holds the tool firmly in place. The design of it is so that when the tool is spinning, the collet is very, very true and it is important to use a good grade collet so that you don’t have any wobble or deformity at all when your tool is spinning because that will cause vibration and it will give you very undesirable results. You always want to make sure too, that you have a couple extra collets as sometimes if you were to have an issue with your program and you break a bit, it will take the collet with it and then you will end up deforming the collet and it won’t be any good. They are not that expensive, it is just something that you need to be aware of that you want to have more than one.
The Tools are commonly referred to as End Mills at times and there are thousands of them. I am not going to get into all of them in this particular podcast but we will talk about very specific types and different applications for those in future episodes of the show. The most common types of end mills are a ball nose and flat nose, Vcarve engraving tool etc. Just like with the collets, if you are working on a job and you are using 1/8th-inch flat nose end mill, when you go to buy your machine make sure that you have more than one because there is nothing that spoils a fun day of CNC than when you break a bit and you don’t have replacement and you have to order one. Typically, end mills are not very expensive, they cost less than $20; I have seen some on Amazon less than $10 a piece. Depending on the type of job that you are doing…if you are doing a carving job for example, sometimes one job will require you to use more than one bit. A lot of times if you are doing an intricate carving on a piece of wood you will use a flat nose, larger diameter like a 3/16th or a 1/4-inch diameter end mill and you will remove the bulk of the material from the part. It will calculate it out in the software and it will get very close to the finish curves that you have on the part that you are going to create. Then what you do is you switch to a ball nose end mill, usually a smaller diameter like 1/8th or 1/16th of an inch and it will go in and it will make very intricate passes and because the ball nose is curved on the bottom, it creates a very smooth, carved-looking finish.
Again, we are going to talk about all of this stuff in future episodes, I am just trying to give you a little bit of an overview right now.
Now that we have identified the major components and parts of a CNC router system, I want to discuss the three basic steps to create a CNC project. They are: design, the tool path software and machine control. When it comes to design, any drawing or CAD program (for those of you who don’t know, CAD stands for Computer Aided Design) will work in a CNC program. There are software such as Sketchup and Inkscape which are free programs. Sketchup is a CAD drawing program and Inkscape is a vector drawing program and there are commercial software such as Adobe Illustrator and Corel Draw, and there are commercial CAD software such as Autocad, Solidworks etc.
We will be diving into specifics in these different software platforms in future episodes but the main thing is that you don’t need to be a drawing wizard, a lot of these programs such as Sketchup is free, it is very easy to use, there are thousands of videos online that will walk you through how to do specific things, and it’s fun. It is the first step in taking your creative idea and getting it into a form where you could actually produce it in real life, so don’t let the design software scare you, we are going to walk through and we are going to make it fun, interesting and give you resources as well to point you in the right direction.
Tool path software is the second step and basically, what that is doing is taking your drawing…taking your design and turning it into instructions that the CNC machine will use to create the final part. It’s going to determine the size and types of tools that you use, you can put that information in and you select various lines on the drawing and you could tell it where to remove material, what tool you are going to use for certain applications and it is going to do all the calculations required to produce all your final output. It is going to create what is called a G-code file or machine code file that is basically the language that the CNC machine uses to tell it what to do and how to move. We are going to use machine control software (which I will talk about in a second) to decipher that code and actually make the machine function based on it. We are going to discuss a lot of software in future episodes. The primary one we are going to focus on is a company called Vector out of the United Kingdom. They have quite a few software programs that we sell at Stepcraft but they are very popular amongst hobbyists and even professional CNC machine users like sign shops and things; programs like Cut 2D, Cut 3D and Vcarve Pro. These programs are very, very simple to use, there is a lot of support…a lot of videos on them, and they really help. Some of them like Vcarve and Cut 2D have basic drawing and design functionality built in as well, so you can actually eliminate the need for a design program by using one of these Vector software. Again, we will talk about that in future episodes.
The other side of it is you could use commercial CAM software such as Mastercam, BobCAD and EzCAM, depending on your experience. I have customers in Stepcraft who are machinists and so they are familiar with programs such as Mastercam and they will use that as a means of converting their drawings into the G-code file. There is no specific software you need, you just need to make sure that you have the right profile set up for the CNC machine that you are going to be using; and again, that’s something we will discuss in more detail.
The final step is what we call Machine Control Software and like I said a minute ago, what that does is it takes the G-code, which, if you were to look at G-code, it is just a bunch of letters and numbers and it doesn’t really mean anything unless you understand what the different codes mean within that. Think of it as just a completely different language. The machine control software will take the G-code, turn it into functions that will tell the machine how to move amongst the X, Y and Z axes. Common software for machine control are: Mach3, WinPCNC and Stepcraft specifically uses UCCNC which is a very powerful and easy to use program. Most of the machine control software will show you some basic functions within the actual program, a lot of them will show you where the tool’s position is… a kind of a graphical representation of it in real time so you can see what portion of the job has been done and what is left to be done – it is graphically represented. You could vary the job speed and it will show you how fast you are moving and what your feed rate is – you could control that on most of these programs on the fly. If you are working on something and you think that you need to run 20 millimetres a second but once you start doing that you can hear the spindle really straining, you have the ability to slow down or speed up that feed rate on the fly. Most programs will tell you how much time has been consumed and how much time is left to complete your job which is good because if it is a long carving job and you know that you have got an hour left, as long as everything is working properly you could walk away and do something else and know you need to check on it within a certain period of time.
The machine control programs will also jog functions that will allow you to move the tool to the X, Y, Z position that would be considered the starting location of the part or if you change bits it will allow you to manually move the head around to get it back to a new starting point. The software is going to remember the home positions once you start the job, so you want to change a tool, you could re-zero it out, tell it go to `Home’ and it is going to know exactly where that is without your having to manually re-do it again. So, that is just some of the basic functions that you get with a machine control software and again, it is three basic, simple steps: design, tool path, machine control. Don’t worry about it, we are going to dive into each of these in future episodes and really break everything down and make it nice and simple for you.
Now that we have covered some of the basics of not only the CNC machine but the software and the steps that are required, if you are new to this industry, this hobby or CNC in general, you might be saying to yourself `wow, this all sounds complicated, I bet you it is going to be very expensive to get started’ and the reality is that there are machines on the market that start from less than $1000, including Stepcraft, we have machines that start under $1000. Many of them come in kit form and you can assemble them in as little as an afternoon, and because they are in kit form you are saving a lot of money on the machine up front because the manufacturer doesn’t have to pay to have somebody put it together. You are also going to save a lot of money on shipping because they come in smaller boxes and it is easier for companies like UPS to ship for a reasonable rate. So these machines can start at under a grand and can go all the way to tens of thousands of dollars for a commercial system. Here is something that I find and I tell a lot of people: the good news is that just about anything that you want to do that you would normally think you need a large commercial CNC router system for, you could actually do on any inexpensive personal desktop model. The only constraint and consideration is the physical work size. Many commercial systems can have work beds on them as big as 4 by 8 feet; however, if you are doing a smaller job you can get away with machines that will be on average 3 by 3 feet (something like that) and anything that you are going to perform as far as milling and carving on these larger machines can be done on a small machine it’s just on a smaller scale.
At Stepcraft, we offer five different models of machines: the 210, the 300, the 420, the 600 and our largest machine which is the 840. If you go look at the Show Notes, I put a chart up there that will show you the comparison of the different size machines, it will give you the work area as well (in inches). That is one of the nice things about the Stepcraft machines, is that you could buy a machine that is specific to the size requirements that you need, so there is no need to buy and spend the money for a large machine if the biggest part you are ever going to work on is 10 by 10 inches as we have a machine specifically for that. The 840 on the other hand, is the largest machine that we have and it is perfect for if you are a wood worker or a carpenter it is large enough to mill things like cabinet doors in one piece, you could do that without having to relocate material. So, there is a huge range in the Stepcraft offering for machines that will meet your specific needs.
Another question that you are probably asking yourself is do you have to be a computer wizard or drawing wizard to be successful. Don’t let that scare you. Yes, all these machines do run around computers, that’s what they are, they’re the CNC machine – Computer Numerical Control; however, you don’t need to necessarily know how to draw. You don’t need to be too intimidated by all this functionality because a) we are going to walk you through everything in future episodes of the podcast and b) there are a lot of helpful videos and things like that on the Internet for most of the basic software.
The other thing that is (kind of) cool is there are sites on line, one of them in particular is my favourite it is called thingiverse.com (and I have a link to that in the Show Notes) where you could download some really cool designs which are very complicated and you could download them for free and use them on your CNC. Years ago when I got my first 3D printer I was so excited with the technology that actually have it do something that the thought of me having to learn how to draw something in CAD to produce it was a little off putting, so when I was turned on to thingiverse.com I was able to go there and pick out an item, download it and run the file off of my printer and as a matter of fact, for the first couple of months that I had my printer, I was printing a lot of things that I specifically got from thingiverse that were premade, while I was teaching myself how to use a simple CAD program so I could make my own parts. So, you don’t need to be scared away it is not a very, very complicated process. There are some things you need to know just like with anything but I assure you that working together we are going to figure it out and we are going to make sure that this is a fun process for you and we are going to help you turn your ideas into reality.
Okay, so that’s it for this first episode. I want to thank you very much for being a part of it and I am very excited to be working with you during the weeks to come and break down this whole CNC world and make it manageable and exciting for you to be successful with it right away. We covered a lot of basics today and in the future episodes I think we are going to take very specific things and we are going to break them down into complete episodes. Today was more of an overview to get the ball rolling so to speak and as we move on we are going to include things like interviews with customers that we have, talking about various projects that they produce, we are going to really break down a lot of the software things and go into details on different tooling. So, we have got a lot planned for you in the weeks to come and I encourage you to please share the podcast with friends and family and I would also appreciate very much, if you like what we are doing here please go to iTunes and give the podcast a 5-star rating if that’s what you feel. The more ratings that we get the faster it’s going to help us move to the top of the list so that this podcast is heard by more and more people; so we would really appreciate that.
I am also going to put up a Show Notes page and the website for this podcast is called www.youcreatepodcast.com and the Show Notes will be at www.youcreatepodcast.com/001. Additionally, you will be able to leave comments on that page and I encourage you to do so. We will have a contact form as well so if you have any questions or anything specifically that you would like us to cover in future episodes please don’t hesitate to do that. Your feedback is what is going to determine the direction of various episodes that we produce so I really encourage that very much.
I want to thank you for listening. I am looking forward to taking this journey with you into the world of CNC and 3D printing and to explore your ideas because ultimately we want to know: what will you create? Have a great week.