One of the chief limitations of hobby scale 3D printing is its inability to print metal. Yes, there are commercial 3D printers that can print metal, even exotic metals like Inconel. But the cost of such 3D printers is prohibitive for all but the most high end applications.
What’s a poor 3D printing hobbyist to do about metal?
One great answer is to use their 3D Printer to create the models that are to be used to cast the part from metal using the lost wax casting technique (known more formally as investment casting). With lost wax, one makes a full size replica of the desired part. That replica is then embedded in a material capable of withstanding the high temperatures of the molten metal to be used for the part. That result is then placed in a kiln where the model (normally wax, but in this case 3D printed plastic) is “burned out” of the mold. It is literally burnt away leaving behind a void shaped exactly like the desired part. Next, molten metal is poured into this new mold to case the part. The material is chipped or washed away and Voila! A new part is born.
We’re close to the half way point on the year and as always, I like to pass along which blog posts and articles (articles being those pages outside the CNCCookbook blog proper) have been the most popular. We have several thousand CNC articles on the site, and there are a lot of undiscovered treasures. Hopefully these 20 leads will help you to find something new and interesting here.
Let’s start with the 10 most popular blog posts so far this year:
1. 10 Tips for CNC Router Aluminum Cutting Success
This one has been on the top for quite a while. Welcome to all the CNC Routers users who are looking to make cutting aluminum easier. It’s very doable, you just need to know a few of the tips.
2. 10 Things Beginning CNC Milling Machine Users Need to Succeed
Intro articles have always been a strong suite for CNCCookbook so I was pleased to see this article for CNC beginners did well.
3. Motion Control Boards Take Mach3 From Hobby Class to Industrial Grade
We cater to professionals as well as DIY CNC’ers. The latter tend to be from the more advanced end of the DIY spectrum,…
Recently a user of G-Wizard Calculator asked to understand better the difference between Calculator’s CADCAM Wizards and its Feeds and Speeds Calculator. It’s a fair question as they look totally different and the CADCAM Wizards are so unique nobody will have had experience with anything like them before they tried G-Wizard.
Let’s start with the Feeds/Speeds Calculator. It’s familiar to any machinist because it presents concepts that have been around for a long time:
The Feeds/Speeds Calculator presents concepts familiar to almost every machinist…
The idea is you work your way through, left to right, top to bottom, until you’ve filled in enough blanks to get back RPM and Feedrate. That basically means filling in the sections labeled “Machine”, “Tool”, and “Cut”. The Mini-Calcs are specialized little calculators that help you with specific problems like Interpolated Holes, Ramping into a Cut, and Plunge Roughing. The answers appear in the “Feeds” section, and the areas below “Feeds” are optional areas to fill in. You can override almost anything G-Wizard calculates and force it to deal with that. For example, you might want to arbitrarily reduce the RPM’s, or you might want to provide your cutter manufacturer’s chipload and surface speed. Most…
Machine tools of all kinds need adjustments from time to time and 3D Printers are no exception. If anything, I have found mine to be quite finicky as I go through the dialing in process. In this article I want to talk about calibrating your extruder steps. That is, the number of steps the motor on the extruder makes to achieve a certain result. Adjusting this value is critical because it determines whether the extruder is injecting too much or too little filament plastic compared to what the software is expecting.
How do we choose the right value for this setting?
There’s more than one way. In theory, we’re talking steps per some unit distance, so we could simply mark the filament relative to some distance, command the extruder to run 10mm of filament through, measure exactly how much went through, and adjust our number accordingly. This is a good step to take, but rather than choosing the “right” value, I wanted to get the “best” results, where “best” is the best subjective result, so I opted for a different method. I tested values on either side of “right” to see which one produced the best results on a test…
This is the seventh installment of our Ultimate Benchtop CNC Mini Mill series. The series is dedicated to helping DIY CNC’ers work through the design considerations and tradeoffs for their CNC Mill projects. Here are the installments so far:
Part 1: Donor Mill
Part 2: CNC Mechanicals (Ballscrews and Such)
Part 3: Close Loop vs Open Loops (Servos vs Steppers)
Part 4: Motion Performance
Part 5: Acceleration and Cutting Forces
Part 6: Motor Selection Wrap Up
In this installment, we’ll wrap up the process for selecting your axis drive motors, leadscrews, and timing belt drives.
Whether you plan to have one from the beginning or add it later, any Benchtop CNC Mill project worth the word “Ultimate” needs to be toolchanger ready. As it turns out, the decisions that need to be made on the taper/toolholders, powered drawbar, and toolchanger, all go hand in hand. Also, they need to be considered right up front to make sure we don’t paint ourselves into a corner when the time comes to add a toolchanger later.
In this installment of the Ultimate Benchtop CNC Mini Mill Series, we will take a look at the decisions that relate to the toolchanger. In the next…
One of the critical problems you must solve when 3D Printing is getting the print to stick to the printer bed. Failure to do so leads to warping and all sorts of other nasty problems. In the worst case the whole print comes lose in the middle of printing and is ruined.
People go to great lengths to avoid this problem, invoking glue sticks, hairspray, ABS + Acetone Slurries (the “Juice”), and who knows what all else. We’ve touched on this problem in a prior article to give you some idea of the different approaches. I am pleased to report that there is an easier way. I contacted the BuildTak people to ask for a sample of their material in a round size that fit my Rostock’s round glass bed. I got the sample from them fairly quickly and proceeded to apply it to the bed. The process is simple, you peel off the backing paper and stick it on. Take a little care that it is well centered on the bed, and peel the backing paper off a little at a time. I used a credit card to help smooth out any bubbles as I was applying the BuildTak…
An important concept that pops up from time to time is a CNC machine’s ability to accelerate. Acceleration is often the real limiting factor to the machine’s motion, more so than absolute rapids speeds, for example. In many real world g-code programs, the cutter may never get up to the commanded speed in some of the blocks. This will cause the program to run more slowly than expected, so understanding what’s at work can either help us make the program faster or make our estimate of its running time more accurate.
Why does inadequate acceleration lead to the cutter never reaching the commanded speed?
Simply put, if the move is too short, there is not enough distance to accelerate to full speed. This can be true for both rapids and feed motion for g-codes like G01 (straight lines) and G02/G03 (arcs). The shorter the distance moved, the less likely the cutter will get to full speed by the end of the move. Clearly, very short moves may suffer more than longer moves. If your CADCAM software is simulating a curve with very short line segments, your g-code program is almost certainly suffering from this problem.
Here is a table that…
The pace of innovation for Desktop CNC has really been flying. First, 3D Printers rode the massive wave of hype and innovation. Expect to see the same with Desktop CNC Routers before too long, and that evolution is what we’re here to talk about today.
Let’s start by defining the term “Desktop CNC Router” also known as “Benchtop CNC Routers” or just “Mini-Routers.” These machines are more formally known as gantry mills, so they’re milling machines. Typical examples work well on wood, plastics, and even some softer metals. If you’ve got one that’s well made, you can cut aluminum and brass on your Desktop CNC Router, for example. The “Desktop” indicates they’re small enough to sit on your desk, so they’re not freestanding. Most industrial CNC Routers are sized to take a full 4′ x 8′ piece of plywood and sometimes even more. Figure the table of a Desktop CNC Router will accomodate workpieces up to 4′ x 4′ and many are much smaller. The little machine pictured to the right was made for me by a fellow named “Widgitmaster” on the CNCZone boards and is tiny as you can tell by the scale of the Dremel tool it uses…
One Wheeled Scooters: they’re not as good as flying cars, but they are pretty cool!
I try to balance the editorial content here at CNCCookbook between learning the art of CNC Manufacturing (you never stop learning, experts and beginners alike) and showing off inspirational articles about CNC Projects you could build or that others have built. It can seem a bit eclectic, but the formula works as our readership has grown to circa 2 million visitors a year and continues to grow like gangbusters. Thanks to all of you readers for that!
And while I’m at it, let me put in a plug for our email newsletter. Click here to subscribe and we’ll add you to the list. In exchange, you’ll receive a digest once a week of the articles published in the last week. A lot of people like to save up several articles and not have to keep checking back. The email newsletter makes that easy.
Now what’s all this about One Wheeled Electric Scooters?
I have been impressed by the efforts to build electric bicycles I’ve seen and have written about them in the past. I aim to build one myself at some point, perhaps even a…
I really love the idea of Food- and Drink-Making CNC Projects, being an amateur chef who has been a guest chef a number of times at our local restaurants. This is the most complete project I’ve come across yet for building your own barbot–a robotic bartender that mixes drinks. It’s called “BarMixvah” and was created by Apple Engineer Yu Jiang Tham. Here is what the machine looks like:
BarMixvah: Your Robotic Bartender…
BarMixvah uses an Arduino (a very popular inexpensive single board computer for projects like these) to control four peristaltic pumps. This is similar to Bartendro, a Kickstarter barbot we’ve written about before. These little pumps are ideal for this application because they simply move rollers over plastic tubing. They’re easy to clean, easy to make food safe, and capable of metering ingredients precisely. Even better, they’re pretty cheap. BarMixvah’s pumps run on 12V DC and cost just $14 apiece on Amazon.
The project includes all the information needed to build your own BarMixvah including the stl files for 3D printing and the code for the software on github. Once complete, BarMixvah is run from a web server, which makes it easy to control from your iPad or other…
I must say, CNCCookbook’s new Rostock 3D Printer has attracted more attention from non-CNC friends across all age groups than any other thing CNCCookbook has done. Part of it is that there’s been an awful lot of hype around 3D Printing, but part of it is I show them an iPhone case made with the 3D printer and they instantly put two and two together and want their own custom phone case. This got me to thinking about what the economics of the 3D Printer are and from there I went on to wondering how well kids could do with a 3D Printer Stand instead of a lemonade stand or other “Kid Friendly” business.
Back in the day I remember traipsing all over town going door to door and offering to stencil paint people’s street number onto the curb by their driveway. We did pretty well (for kids incoming anyway) until some high school kids showed up with a car and managed to engulf all the unpainted territory much faster than we could access it. Those darned big companies are always messing with us little guys! What I’m wondering is whether this kind of a business would work for kids. …
Finishing techniques give your work that final professional look, so they’re worth paying attention to. 3D printing with a filament extruder is a process that leaves a lot of room for improvement in the surface finish of the parts. Most hobby-grade printers leave very visible patterns from the extrusion that are sometimes attractive and other times just seem to detract from the overall appearance of the part. It’s hard to get rid of them entirely, but there are some techniques available that help. One of the easiest is to polish your ABS parts with Acetone vapor. This is a very cheap and easy technique that anyone working with 3D Printed ABS plastic should try.
First thing you need is a heated chamber to contain your part and vaporize the Acetone. There’s a piece of cookware called a “Presto Kitchen Kettle Multi-Cooker Steamer”. It’s just a cheap and cheerful little self-heated pot that includes an electrical thermometer control, a tempered glass lid, and a drop in basket. Perfect for our task and cheap. I ordered mine from Amazon for $40, but they can be had cheaper if you head out to your local discount store. In addition, you’ll need a small…
I just added a chapter on work offsets to the CNCCookbook G-Code Tutorial. It covers all the basics including:
– Why you’d use work offsets
– Different g-codes associated with work offsets
– Different g-code dialects for accessing extended work offsets
– G92, an older way to program offsets that’s still useful today
– Work offsets in macros and work offsets with G10
Lots of great information there for those wishing to learn the valuable tool that is work offsets. Plus, there is a complete explanation of how to access work offsets in the G-Wizard Editor so you can play with g-code programming using work offsets on the GW Editor simulator.
If you’re not able to read and program g-code yet, give our tutorial a try. It’s extremely easy and everything is arranged into bite-sized installments. Just set yourself on a course to read a new chapter every evening or every couple of days and you’ll be surprised at how easy it is to pick up g-code programming. It’s an important tool to have in your toolbox if you’re involved with CNC in any way.…
Remember those MIT students that had the crazy handheld “CNC” router? That was one of the all-time popular articles for CNCCookbook back in the day. Well, it seems they’ve started a company they call Tactia to build these routers and a lot more. It’s not quite full CNC, but much more than ordinary hand tools. Here it is in their own words:
CNC enables complex shapes to be economically produced and shared across the world. However, the process of using CNC is still complex, and somehow doesn’t feel human. That is where we come in. We have figured out how to blend the power of computer control with the flexibility, simplicity, and pleasure of using a hand tool. Whether you are a traditional craftsperson or a CNC guru, our tools will change the way you work.
Here are some projects done by a novice woodworker freehand using one of their routers:
I don’t know about you, but that looks to me like extremely nice work from a novice woodworker.
These routers work by letting the human hand guide the gross positioning while watching a screen and having the machine adjust the micro-position to be faithful to the design. That’s why…
It seems an unlikely combination, but when you’re an entrepreneur, anything is possible. Luke Colby’s company, Rocket Thermodynamix, makes parts for rockets. I’m talking about full-on beautifully machined aerospace quality components. Here is a typical example:
A pyrotechnic actuated poppet valve…
Yeah, I don’t know what you’d use one of these for either. Maybe Luke can chime in. I have been amazed and impressed at the willingness of private industry to get involved in the space program on their own, and starting a small company to do so may very well be the next step. One of the things this company is trying to do along the way is use Kickstarter to help pay for some new CNC machine tools. Specifically, they’ve created what I’m calling a Space Age Pet Food Bowl and what they’re calling Pest Barrier Pet Food Bowl and it’s been launched as a Kickstarter. If you’ve ever discovered a line of ants plundering your pet’s food bowl, you’ll know immediately why this is a good idea. The Pest Barrier Food Bowl actually has a water-filled moat protecting the food so the ants can’t get to it. In addition, it serves as a bubbler that keeps fresh…