In our time, among handicraft people, you can increasingly find new machines that are controlled not by hands, as we are all used to, but by computer software and computerized equipment. This innovation is called CNC (Computer Numerical Control).
This technology is used in many institutions, in large industries, as well as in the master's workshops. Automated system management allows you to save a lot of time, as well as improve the quality of products.
The automated system is controlled by a program from a computer. This system includes asynchronous motors with vector control, having three axes of movement of the electric engraver: X, Z, Y. Below we will consider what machines with automatic control and calculations.
As a rule, all CNC machines use an electric engraver, or a milling cutter, on which you can change nozzles. Machine with numerical control It is used to give certain materials elements of decor and not only. CNC machines, due to advances in the computer world, must have many functions. These features include:
Milling
The mechanical process of processing the material, during which the cutting element (nozzle, in the form of a cutter) produces rotational movements on the surface of the workpiece.
Engraving
It consists in applying this or that image on the surface of the workpiece. To do this, use either milling cutters or a chisel (a steel rod with one end pointed at an angle).
drilling
Machining of the material by cutting, with the help of a drill, due to which holes of different diameters and holes with many faces of different sections and depths are obtained.
laser cutting
The method of cutting and cutting the material, in which there is no mechanical action, the high accuracy of the workpiece is maintained, and the deformations performed by this method have minimal deformations.
Plotter
High precision drawing the most complex schemes, drawings, geographical maps. Drawing is done at the expense of the writing block, by means of a specialized pen.
Drawing and drilling PCBs
Production of boards, as well as drawing electrically conductive circuits on the surface of a dielectric plate. Also drilling small holes for radio components.
It is up to you to decide what functions your future CNC machine will perform. And then consider the design of the CNC machine.
Variety of CNC machines
Technological features and capabilities of these machines are equivalent to universal machines. However, in the modern world, there are three types of CNC machines:
Turning
The purpose of such machines is to create parts according to the type of bodies of revolution, which consists in processing the surface of the workpiece. Also manufacture of internal and external threads.
Milling
The automated operation of these machines consists in the processing of planes and spaces of various body blanks. Carry out milling flat, contour and stepped, under different angles, as well as from several sides. Drilling holes, threading, reaming and boring workpieces.
Drilling - boring
They perform reaming, drilling holes, boring and reaming, countersinking, milling, threading and much more.
As we can see, CNC machines have a wide range of functions that they perform. Therefore, they are equated with universal machines. All of them are very expensive and it is simply impossible to buy any of the above installations, due to financial insufficiency. And you might think that you have to do all these actions manually, throughout your life.
You may not be upset. Skillful hands countries, since the first appearance of factory CNC machines, began to create home-made prototypes that work no worse than professional ones.
All component materials for CNC machines can be ordered on the Internet, where they are freely available and are quite inexpensive. By the way, the body of an automated machine can be made by hand, and for correct dimensions can be accessed on the Internet.
Tip: Before choosing a CNC machine, decide what material you will be processing. This choice will be of major importance in the construction of the machine, as it directly depends on the size of the equipment, as well as the cost of it.
The design of the CNC machine depends entirely on your choice. You can purchase a ready-made standard set of all necessary details and just assemble it in your garage or workshop. Or order all equipment separately.
Consider a standard set of parts on the picture:
- Directly the work area, which is made from plywood, is a tabletop and a side frame.
- Guide elements.
- Guide holders.
- Linear bearings and plain bushings.
- Support bearings.
- Leading screws.
- Stepper motor controller.
- Controller power supply.
- Electric engraver or milling cutter.
- Coupling connecting the shaft lead screw with stepper motor shaft.
- Stepper motors.
- Running nut.
Using this list of parts, you can safely create your own CNC wood router with automated work. When you assemble the entire structure, you can safely get to work.
Principle of operation
Perhaps the most important element on this machine is a milling cutter, engraver or spindle. It depends on your choice. If you have a spindle, then the tail of the cutter, which has a collet for fastening, will be tightly attached to the collet chuck.
The chuck itself is directly mounted on the spindle shaft. The cutting part of the cutter is selected based on the selected material. An electric motor, which is located on a moving carriage, rotates the spindle with a cutter, which allows you to process the surface of the material. The stepper motors are controlled by the controller, which receives commands from computer program.
Electronics The machine works directly on the computer software, which must be supplied with the ordered electronics. The program sends commands in the form of G-codes to the controller. Thus, these codes are stored in the RAM of the controller.
After selecting a processing program on the machine (finishing, roughing, three-dimensional), the commands are distributed to stepper motors, after which the surface of the material is processed.
Tip: Before starting work, it is necessary to test the machine with a specialized program and skip a trial part to make sure that the CNC works correctly.
Assembly
Machine assembly do it yourself won't take you too long. Moreover, on the Internet now you can download a lot of different schemes and drawings. If you bought a set of parts for a homemade machine, then its assembly will be very fast.
So let's look at one of drawings actual manual machine.
Drawing of a homemade CNC machine.
As a rule, first of all, a frame is made of plywood, 10-11 millimeters thick. tabletop, side walls and a movable portal for the installation of a router or spindle, are made only of plywood material. The tabletop is made movable, furniture guides of appropriate sizes are used.
As a result, you should get such a frame. After frame structure is ready, a drill and special crowns come into play, with which you can make holes in plywood.
The frame of the future CNC machine.
In the finished frame, it is necessary to prepare all the holes in order to install bearings and guide bolts in them. After this installation, it is possible to install all fasteners, electrical installations, etc.
After assembly is complete, milestone becomes setting software machine tool and computer program. When setting up the program, the operation of the machine is checked for the correctness of the specified dimensions. If everything is ready, you can start the long-awaited work.
Tip: Before starting work, it is necessary to check the correct fastening of the workpiece material and the reliability of the fastening of the working nozzle. Also make sure that the selected material matches the manufactured machine.
Equipment setup
Adjustment of the CNC machine is carried out directly from the working computer on which the program for working with the machine is installed. It is in the program that the necessary drawings, graphs, drawings are loaded. Which in sequence are converted by the program into G - codes necessary to control the machine.
When everything is loaded, trial actions are performed with respect to the selected material. It is during these actions that a check is made of all the necessary preset sizes.
Tip: Only after a thorough check of the machine's performance, you can start full-fledged work.
Safety
The rules and safety precautions when working with this machine are no different from working on all other machines. Below are the most basic ones:
- Check the correct operation of the machine before work.
- Clothing must be properly tucked in so that nothing sticks out anywhere and cannot get into working area machine.
- You must wear a headdress that will hold your hair.
- There should be a rubber mat near the machine or a low wooden crate to protect against electrical leakage.
- Access to the machine by children must be strictly prohibited.
- Before using the machine, check all fasteners for their strength.
Advice: It is necessary to approach the work on the machine with a sober head and understanding that if you work incorrectly, you can cause irreparable harm to yourself.
With complete safety requirements for working with the machine, you can find it on the World Wide Web, i.e. on the Internet and check them out.
Video reviews
Overview of the assembly of a homemade CNC machine
Video review simple machine CNC
Features Overview homemade CNC machine tool
Overview of stepper motors
Review video multi-channel stepper motor driver
IMPORTANT! Manufacturing printed circuit boards on machines of the HIGH-Z series - a very accurate and fast process. HIGH-Z CNC machines are the best for today equipment for the production of printed circuit boards. Our machines can mill conductive strip and drill holes at the same time! PCB Manufacturing Technology on cnc machines HIGH-Z allows you to achieve very high milling accuracy - 0.02 mm. Equipment for the production of printed circuit boards is small.
Production of printed circuit boards on HIGH-Z machines
CNC Machine LLC supplies the best German equipment for the production of printed circuit boards - CNC machines of the HIGH-Z and Raptor series. We are the official distributor of these machines in Russia.
Printed circuit board manufacturing technology on a HIGH-Z cnc machine
You design your PCB in PCAD for example, save the file as a .plt file (HPGL) . Next, you need to run the PCNC program (supplied).
For prototypes or small series it is essential to be able to mill printed circuit boards. HIGH-Z cnc engraving and milling machines have the ability to mill the conductive strip with an accuracy of approximately 0.1 - 0.15 mm.
Perhaps you know about personal experience, how inconvenient the lack of milling is and what additional equipment is needed to mill printed circuit boards on your own.
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PCB prototyping equipment
On CNC milling machines of the HIGH-Z series, it is possible to produce prototypes of printed circuit boards for small-scale production from materials such as aluminum, textolite, fiberglass, lavsan and other fibrous materials.
Ability to produce double-sided printed circuit boards. This video of the Perm company LLC Uralintelcom demonstrates double-sided printed circuit board manufacturing process with all the necessary operations: milling tracks, drilling holes, cutting the printed circuit board on the HIGH-ZS-400 machine. It is also possible, if necessary, to apply adhesive compositions to the board.
For the production of printed circuit boards, a mandatory option is a mechanical depth adjuster, the spring-loaded mechanism of which reads the surface roughness, thereby processing the material to a clearly defined depth.
Advantage of HIGH-Z cnc machine:
As I remember now, on February 23rd I came across a post on Tudey, where a person wanted to engrave printed circuit boards on a 3D printer. In the comments, they advised not to torture the printer and pay attention to the Cyclone PCB Factory project.
Fired up with the idea. Later, at some point, I even regret that I took it, but it will be much later.
I dreamed of my own CNC router for printed circuit boards for a very long time, it was the second Wishlist after a 3D printer. I decided to repeat the project, especially since I already had something in the bins.
I downloaded the project files and without hesitation began to print the details. Managed in about a week. Printed everything except the Z axis.
There are no detailed photographs of all the details. Someone took a screenshot of the print settings and the result. Nozzle 0.4, layer height 0.24. I also printed with a layer of 0.28 - it prints quite normally.
I wanted to make the machine colored, so I printed different parts with plastic of different colors. Plastic used ABS Prostoplast. Cosmos colors, grassy green, scarlet sunset.
It would be better to print everything in gray space. Red and green turned out to be quite fragile and some of the parts cracked during assembly. Something was cured with acetone, something was reprinted.
Accessories:
I had three free stepper motors, I bought them for a 3D printer project, I decided to temporarily use them.
I got 8mm guides from inkjet printers, tearing several printers into organs. Wool local commissions, Avito. Donors were HP inkjet printers for 100-200 rubles apiece. The long guide was sawn into two parts, on the X and Z axes.
The paper clamp from which I removed the rubber rollers went to the Y axis. The length was just enough to cut along the knurling.
Linear bearings remained from the 3D printer, I transferred the printer to bronze bushings with polka dots.
As electronics, I decided to use one of my Arduino Uno atmega328p. I bought a cnc shield 3.0 board for Arduino on Ali for 200 kopecks.
Power supply 12V from Leroy Merlin. I bought to power three 12V halogens, but he did not pull them. I had to repair the transformer for Tachibra halogens, and this power supply took root on the machine.
I installed the 8825 drivers on the 3D printer, I still have a4988 from the printer. And put them on the machine.
I ordered 608ZZ bearings on Ali, a dozen for 200 rubles with kopecks ..
I planned to use my Chinese GoldTool engraver as a spindle.
M8 threaded studs got from work for free, left from some kind of installation. Picked up almost "from the trash."
While the project was being printed and the details were moving with Ali, I asked a furniture maker friend to cut out a base and a table from MDF. He was not too lazy and did not regret the scraps, sawed out 2 bases and 2 tables. Pictured is one of the sets.
I didn’t have plywood in the bins, a greedy animal did not allow me to buy a sheet of plywood. By the way, MDF came up very well.
Began to assemble the machine. Everything would be fine, but the standard 13 nuts fell through and dangled inside the gear, the 14 nuts did not fit into the gears. I had to melt the 14th nuts into the gears with a soldering iron.
Gears or dangling on axles stepper motor, or did not climb.
The nuts of the m3 screws were scrolled in the landing slots.
I found several square nuts for m3 thread (I once dismantled some kind of plug from it), which fit perfectly and did not scroll. At work, I also found such plugs and put them on nuts. Basically, these are guide mounts. Ordinary nuts for m3 threads had to be held with a thin sting of a screwdriver so that they would not scroll.
Somehow collected. Later, while reading topics about Cyclone, I came across recycled machine parts for metric fasteners. From this set, I re-printed the gears and the mount of the limit switch along the Z axis. It’s a pity I didn’t come across this set of spare parts earlier. I would print these parts.
Hoping to use my Chinese engraver, I first printed out one dremel mount from the kit, then the second. It did not fit, my engraver did not climb into one. The original dremel, the simplest, cost a little over three thousand rubles. For what???
Extra parts.
And yet, linear bearings in their nests dangled like something in an ice hole.
I had to order a 200W spindle from Ali for a little over a thousand collet clamp ER11. Successfully got on discounts and used the coupon.
While the spindle was driving, I printed out a mount for it from the machine kit. And again a puncture, it is just as flawed. And not a word about the clamp for the spindle.
As a result, I found and printed out this mount for a 52mm spindle. After a little refinement, the mount fit on the machine, the spindle entered it well.
But the bearings on the Cargo bushings had to be removed from them. Delivered Chinese LM8UU
Separately, I want to say about the Chinese bearings 608zz. New bearings with backlash. Terrible. One that is relatively inexpensive. We did not look for bearings.
By the way, the bearings entered the seats in the same way as something in an ice hole. IN seats bearings wobbled. I don't know if this is a bug or a feature. As a result, he wound electrical tape on the bearing races.
Chinese lm8uu and lm8luu from a 3D printer also turned out to be rubbish. As a result, I made plain bearings on Cargo 141091 bushings for the Y axis. I printed out a plastic clip and inserted a pair of bushings into it. The resulting bearings are inserted into the mounts.
On the Z axis I chose the more or less lively lm8uu. I put the lm8uu upper bearing on the X axis, and instead of the two lower ones, I printed out a plastic clip according to the lm8luu size and inserted a pair of Cargo bushings into it.
Luckily I bought them at the time. Useful.
During the assembly of the machine, I regretted that I had taken it. But, there was nowhere to go, it was necessary to complete the project. Collected. Launched!
Some more photos of the build process.
The very beginning of the build...
Once again washing the sink from the red stains of ferric chloride, after etching the board, I thought that it was time to automate this process. So I started to make a device for making circuit boards, which can already be used to create the simplest electronics.
Below I will talk about how I made this device.
The basic process of manufacturing a printed circuit board using the subtractive method is that unnecessary sections of the foil are removed from the foil material.
Today, most electronics engineers use technologies such as laser ironing to home production boards. This method involves removing unnecessary plots foil using chemical solution, which corrodes the foil in unnecessary places. The first experiments with LUT a few years ago showed me that this technology is full of little things, sometimes completely hindering the achievement of an acceptable result. Here is the preparation of the surface of the board, and the choice of paper or other material for printing, and the temperature in conjunction with the heating time, as well as the features of washing off the remnants of the glossy layer. You also have to work with chemistry, and this is not always convenient and useful at home.
I wanted to put some device on the table, to which, like a printer, you can send the source of the board, press a button, and after a while get the finished board.
With a little googling, you can find out that people, starting from the 70s of the last century, began to develop desktop devices for the manufacture of printed circuit boards. First appeared milling machines for printed circuit boards that cut out tracks on a foil textolite with a special cutter. The essence of the technology lies in the fact that at high speeds, the cutter, mounted on a rigid and precise CNC coordinate table, cuts the foil layer in the right places.
The desire to immediately buy a specialized machine passed after studying the prices from the supplier. I, like most hobbyists, am not ready to lay out such money for a device. Therefore, it was decided to make the machine yourself.
It is clear that the device must consist of a coordinate table that moves cutting tool to the desired point and the cutting device itself.
There are plenty of examples on the internet of how to do it. coordinate table for every taste. For example, the same RepRap cope with this task (corrected for accuracy).
From one of my previous hobby plotter projects, I have a homemade XY table. Therefore, the main task was to create a cutting tool.
Equipping the plotter with a miniature engraver like a Dremel would be a logical step. But the problem is that a plotter that can be assembled cheaply at home is difficult to make with the necessary rigidity, parallelism of its plane to the plane of the textolite (even the textolite itself can be curved). As a result, cut boards on it more or less good quality would not have been possible. In addition, the fact that the cutter dulls over time and loses its cutting properties spoke against the use of milling. It would be great if copper could be removed from the surface of the textolite in a non-contact way.
already exist laser machines German manufacturer LPKF, in which the foil is simply evaporated by a powerful infrared semiconductor laser. Machine tools are distinguished by accuracy and speed of processing, but their price is even higher than that of milling machines, and it is not yet an easy task to assemble such a thing from materials available to everyone and somehow reduce its cost.
From the above, I formed some requirements for the desired device:
- Price comparable to the cost of an average home 3D printer
- Non-contact copper removal
- The ability to assemble the device from the available components yourself at home
So I began to think about a possible alternative to the laser in the field of non-contact removal of copper from textolite. And I came across a method of electrospark processing, which has long been used in metalworking for the manufacture of precision metal parts.
With this method, the metal is removed by electric discharges, which evaporate and spray it from the surface of the workpiece. Thus, craters are formed, the size of which depends on the energy of the discharge, its duration and, of course, the type of workpiece material. In its simplest form, electrical erosion began to be used in the 1940s for punching holes in metal parts. Unlike traditional machining, holes could be made in almost any shape. Currently, this method is actively used in metalworking and has given rise to a whole series of types of machine tools.
An obligatory part of such machines is a current pulse generator, a system for supplying and moving the electrode - it is the electrode (usually copper, brass or graphite) that is the working tool of such a machine. The simplest current pulse generator is a simple capacitor of the required rating connected to a source constant voltage through a current limiting resistor. In this case, the capacitance and voltage determine the energy of the discharge, which in turn determines the size of the craters, and hence the cleanliness of processing. True, there is one significant nuance - the voltage on the capacitor in the operating mode is determined by the breakdown voltage. The latter is almost linearly dependent on the gap between the electrode and the workpiece.
During the evening, a prototype of an erosion tool was made, which is a solenoid, to the armature of which a copper wire is attached. The solenoid provided vibration of the wire and interruption of contact. LATR was used as a power source: the rectified current charged the capacitor, and the alternating current fed the solenoid. This design was also fixed in the plotter pen holder. In general, the result met expectations, and the head left continuous stripes with torn edges on the foil.
The method clearly had the right to life, but it was necessary to solve one problem - to compensate for the consumption of wire, which is consumed during operation. This required the creation of a feed mechanism and a control unit for it.
After that, I began to spend all my free time in one of the hackspaces of our city, where there are machine tools for metalworking. A long effort began to make an acceptable cutting device. The erosion head consisted of a pair of rod-bushing providing vertical vibration, a return spring and a pulling mechanism. To control the solenoid, it was necessary to make a simple circuit consisting of a pulse generator of a given length on the NE555, a MOSFET transistor, and inductive sensor current. Initially, it was supposed to use the self-oscillation mode, that is, to apply a pulse to the key immediately after the current pulse. In this case, the oscillation frequency depends on the size of the gap, and the drive is controlled according to the measurement of the period of self-oscillations. However, a stable self-oscillating mode turned out to be possible in the range of head oscillation amplitudes, which was less than half of the maximum. Therefore, I decided to use a fixed frequency of the oscillations generated by the hardware PWM. In this case, the state of the gap between the wire and the board can be judged by the time between the end of the opening pulse and the first current pulse. For greater stability during operation and improvement of frequency characteristics, the solenoid was fixed above the wire pulling mechanism, and the armature was placed on an duralumin bracket. After these improvements, it was possible to achieve stable operation at frequencies up to 35 Hz.
Having fixed the cutting head on the plotter, I began experiments on cutting insulating tracks on printed circuit boards. The first result is achieved and the head more or less steadily provides a continuous cut. Here is a video demonstrating what happened:
The fundamental possibility of fabricating circuit boards using electrospark processing has been confirmed. In the near future, we plan to improve accuracy, increase processing speed and cut cleanliness, as well as put some of the developments in the public domain. I also plan to adapt the module for use with RepRap. I will be glad to ideas and remarks in comments.
We produce mini CNC drilling machines for the manufacture of printed circuit boards. You can buy equipment for drilling and milling boards and cases of electronic equipment from us at an affordable price.
Machine tools SK "Router" for the manufacture of printed circuit boards
In the product catalog of IC Router, equipment for the production of printed circuit boards is presented drilling machines with CNC. Models for printed circuit boards are designed on the basis of our milling and engraving machines and are equipped with special high-speed spindles. The presence of such a spindle allows you to drill and mill printed circuit boards with high speed and accuracy.
If you need a more versatile machine, you can see our standard mini milling machines and general purpose drilling equipment.
Application area
Mini machines for printed circuit boards SK "Router" are used at enterprises of various industries: from general production to aviation and space. In addition to drilling printed circuit boards on such machines, it is possible to successfully carry out milling of cases of radio-electronic equipment. Thus, it is possible to realize the complete production of electronic devices.
Complete set of drilling machines
The basic supply of machines for printed circuit boards includes a set of equipment sufficient to start manufacturing boards in serial mode. At the same time, to increase productivity and ease of operation on the machine, the equipment can be understaffed additional options: CNC system, automatic tool changer, coolant and other technological equipment.
PCB drilling video
Watch the PCB manufacturing process on one of our drilling machines:
