Homemade CNC milling machine. Homemade CNC milling machine: we assemble it with our own hands Homemade CNC milling machines from plywood

Complex processing various materials has long ceased to be the lot of factory floors. Twenty years ago, the most that home craftsmen could afford was figure cutting with a jigsaw.

Today, hand-held milling cutters and cutting lasers can easily be purchased at a household tool store. Various guides are provided for linear processing. What about cutting out complex shapes?

Basic tasks can be accomplished using a template. However this method has disadvantages: firstly, you need to make the template itself, and secondly, the mechanical pattern has limitations on the size of the curves. And finally, the error of such devices is too great.

A solution has long been found: a CNC machine allows you to cut out such complex shapes from plywood with your own hands that “jigsaw operators” can only dream of.

The device is a cutting tool coordinate positioning system controlled by a computer program. That is, the processing head moves along the workpiece in accordance with a given trajectory. Accuracy is limited only by the size of the cutting attachment (mill or laser beam).


The possibilities of such machines are endless. There are models with two-dimensional and three-dimensional positioning. However, their cost is so high that the purchase can only be justified by commercial use. All that remains is to assemble the CNC machine with your own hands.

The principle of operation of the coordinate system

The basis of the machine is a powerful frame. Perfectly used as a basis Smooth surface. It also serves as a work desk. The second basic element is the carriage on which the tool is mounted. It could be a Dremel manual frezer, laser gun - in general, any device capable of processing a workpiece. The carriage must move strictly in the plane of the frame.

First, let's look at a two-dimensional setup

You can use the table surface as a frame (base) for a DIY CNC machine. The main thing is that after all the elements are adjusted, the structure no longer moves, remaining firmly screwed to the base.

To move in one direction (let's call it X), two guides are placed. They must be strictly parallel to each other. A bridge structure, also consisting of parallel guides, is installed across it. The second axis is Y.


By specifying the movement vectors along the X and Y axes, you can position the carriage with high accuracy (and with it the cutting tool) to any point on the desktop plane. By choosing the ratio of movement speeds along the axes, the program forces the tool to move continuously along any, even the most complex, trajectory.

A condition for performing professional woodwork is availability. The roads available for sale are not affordable for everyone. Therefore, many make them with their own hands, saving money and enjoying the creative process.

There are two options for manufacturing mini machines for:

• purchasing a set of parts and its manufacture (Modelist kits costing from 40 to 110 thousand rubles);
• make it yourself.

Let's consider making mini CNC milling machines with your own hands.

Selection of design features

The list of actions when developing and manufacturing a mini device for wood milling is as follows:

1. First you need to decide what kind of work you are talking about. This will tell you what dimensions and thicknesses of parts can be processed on it.
2. Make a layout and a proposed list of parts for a homemade desktop machine for making it yourself.
3. Choose software to bring it into working condition so that it works according to a given program.
4. Purchase the necessary components, parts, products.
5. Having the drawings, make the missing elements with your own hands, assemble and debug the finished product.

Design

A homemade machine consists of the following main parts:

• a bed with a table placed on it;
• calipers with the ability to move the cutting mill in three coordinates;
• spindle with cutter;
• guides for moving calipers and portal;
• a power supply that provides electricity to the motors, controller or switching board using microcircuits;
• drivers to stabilize operation;
• vacuum cleaner for collecting sawdust.

Guides are installed on the frame for moving the portal along the Y axis. Guides are placed on the portal for moving the support along the X axis. The spindle with the cutter is attached to the support. It moves along its guides (Z axis).

The controller and drivers provide automation of the CNC machine by transmitting commands to electric motors. Using the Kcam software package allows you to use any controller and provides control of motors in accordance with the part drawing entered into the program.

The structure must be made rigid in order to withstand the working forces that arise during operation and not lead to vibrations. Vibrations will lead to a decrease in the quality of the resulting product and tool breakage. Therefore, the dimensions of the fastening elements must ensure the solidity of the structure.

A homemade CNC milling machine is used to obtain a three-dimensional 3D image on wooden part. It is mounted on the table of this device. It can also be used as an engraving tool. The design ensures the movement of the working body - the spindle with the installed cutter in accordance with a given action program. The support moves along the X and Y axes along polished guides using stepper motors.

Moving the spindle along the vertical Z axis allows you to change the depth of processing in the created wood drawing. To obtain a 3D relief design, you need to make drawings. It is advisable to use different kinds cutters that will allow you to get best parameters display the picture.

Selection of components

For guides, steel rods D = 12 mm are used. For better movement of the carriages, they are ground. Their length depends on the size of the table. You can use hardened steel rods from a dot matrix printer.

Stepper motors can be used from there. Their parameters: 24 V, 5 A.

It is advisable to secure the cutters with a collet.

For a homemade mini milling machine, it is better to use a factory-made power supply, since the performance depends on it.

The controller must use capacitors and resistors in surface-mount SMD packages.

Assembly

To collect homemade machine to mill 3D wood parts with your own hands, you need to make drawings, prepare necessary tool, components, manufacture missing parts. After this, you can begin assembly.

The sequence of assembling a mini CNC machine with 3D processing with your own hands consists of:

1. The caliper guides are installed in the sidewalls along with the carriage (without a screw).
2. the carriages are moved along the guides until their movement becomes smooth. This grinds in the holes in the caliper.
3. tightening the bolts on the calipers.
4. fastening assembly units on the machine and installing screws.
5. installation of stepper motors and connecting them to screws using couplings.
6. The controller is separated into a separate block to reduce the influence of operating mechanisms on it.

A homemade CNC machine must be tested after assembly! Testing of 3D processing is carried out using gentle modes to identify all problems and eliminate them.

Work in automatic mode provided by software. Advanced computer users can use power supplies and drivers for controllers and stepper motors. The power supply converts the incoming AC (220 V, 50 Hz) into D.C. necessary to power the controller and stepper motors. For them, machine control with personal computer passes through the LPT port. The working programs are Turbo CNC and VRI-CNC. To prepare the drawings necessary for implementation in a tree, programs are used graphic editors CorelDRAW and ArtCAM.

Results

A homemade mini CNC milling machine for producing 3D parts is easy to operate, ensures accuracy and quality of processing. If necessary, do more complex work you need to use stepper motors of higher power (for example: 57BYGH-401A). In this case, to move the calipers, you need to use timing belts to rotate the screws, rather than a clutch.

Installation of the power supply (S-250-24), switching board, and drivers can be done in an old computer case by modifying it. You can install a red “stop” button on it for emergency shutdown of the equipment.

It is difficult to manufacture; in addition to the technical components, it has an electronic device that only a specialist can install. Contrary to this opinion, the opportunity to assemble a CNC machine with your own hands is great if you prepare the necessary drawings, diagrams and component materials in advance.

Carrying out preparatory work

When designing a CNC with your own hands at home, you need to decide according to what scheme it will work.

Often a used one is used as the basis for a future device.

Drilling machine can be used as a basis for a CNC machine

It will require replacing the working head with a milling head.

The greatest difficulty when designing a CNC machine with your own hands is the creation of a device with which the working tool moves in three planes.

Carriages taken from a conventional printer will help partially solve the problem. The tool will be able to move in both planes. It is better to choose carriages for a CNC machine from a printer that has large dimensions.

Such a scheme allows you to later connect control to the machine. The downside is that a CNC milling machine only works with wooden, plastic, and thin metal products. This is due to the fact that the printer carriages do not have the required rigidity.

Attention must be paid to the engine of the future unit. Its role is reduced to moving the working tool. The quality of work and the ability to perform milling operations depend on this.

A good option for homemade CNC The router is a stepper motor.

An alternative to such an engine is an electric motor, previously improved and adjusted to the standards of the device.

Anyone using a stepper motor allows not to use a screw drive; this does not in any way affect the capabilities of such a CNC machine for wood. It is recommended to use toothed belts for milling on such a unit. Unlike standard belts, they do not slip on the pulleys.

It is necessary to correctly design the milling cutter of the future machine; for this you will need detailed drawings.

Materials and tools required for assembly

The general set of materials for a CNC machine includes:

• cable 14–19 m long;
• , wood processing;
• chuck for cutter;
• frequency converter having the same power as the spindle;
• bearings;
• control board;
• water pump;
• cooling hose;
• three stepper motors for three axes of structure movement;
• bolts;
• protective cable;
• screws;
• plywood, chipboard, wood board or metal structure to choose from as the body of the future device;
• soft type coupling.

When making your own, it is recommended to use a spindle with coolant. This will allow you not to turn it off every 10 minutes to cool down. A homemade CNC machine is suitable for the job; its power is at least 1.2 kW. The best option will become a 2 kW device.

The set of tools required for the manufacture of the unit includes:

• hammers;
• electrical tape;
• assembly keys;
• glue;
• screwdriver;
• soldering iron, sealant;
• grinder, it is often replaced with a hacksaw;
• pliers, welding unit, scissors, pliers.

Simple DIY CNC machine

Procedure for assembling the machine

A homemade CNC milling machine is assembled according to the following diagram:

• production of drawings and device diagrams indicating the electrical equipment system;
• purchase of materials containing a future homemade CNC machine;
• installation of the frame, on which the engines, working surface, portal, spindle will be mounted;
• portal installation;
• setting the Z axis;
• fixation work surface;
• spindle installation;
• installation of a water cooling system;
• installation of electrical system;
• connecting the board, with its help the device is controlled;
• software configuration;
• starting start of the unit.

The base for the frame is a material made of aluminum.

The frame needs to be made from aluminum

Profiles made from this metal are selected with a cross-section of 41*81 mm with a plate thickness of 11 mm. The frame body itself is connected using aluminum corners.

The installation of the portal will determine how thick the product can be processed by the CNC machine. Especially if it is made by yourself. The higher the portal, the thicker the product it can process. It is important not to install it too high, as this design will be less durable and reliable. The portal moves along the X axis and carries the spindle.

An aluminum profile is used as the material for the working surface of the unit. Often they take a profile that has T-slots. For home use accepted, its thickness is at least 17 mm.

After the frame of the device is ready, begin installing the spindle. It is important to install it vertically, since it will need to be adjusted in the future; this is done to fix the required angle.

To install the electrical system, the following components must be present:

• power unit;
• computer;
• stepper motor;
• pay;
• stop button;
• motor drivers.

The system requires an LPT port to operate. In addition, it is installed that controls the operation of the device and allows you to answer the question of how to perform this or that operation. The control is connected via motors to the milling machine itself.

After the electronics are installed on the machine, you will need to download drivers and programs necessary for operation.

Common assembly errors

A common mistake when assembling a machine with a numerical program controlled There is a lack of a drawing, but the assembly is carried out according to it. As a result, omissions arise in the design and installation of apparatus structures.

Often, incorrect operation of the machine is associated with an incorrectly selected frequency converter and spindle.

For correct operation of the machine, it is necessary to select the correct spindle

In many cases, stepper motors do not receive proper power, so a special separate power supply must be selected for them.

It must be taken into account that a correctly installed electrical circuit and software allows you to perform numerous operations of varying levels of complexity on the device. A mid-level craftsman can make a CNC machine with his own hands; the design of the unit has a number of features, but with the help of drawings it is not difficult to assemble the parts.

It’s easy to work with a CNC built by yourself; you need to study the information base, carry out a series of training works and analyze the condition of the unit and parts. Do not rush, jerk moving parts or open the CNC.

Axes locationX, Y, Zdesktop CNC milling and engraving machine:

The Z axis moves the tool (mill) vertically (down-up)
X axis - moves the Z carriage in the transverse direction (left-right).
Y axis - moves the movable table (back and forth).

You can familiarize yourself with the device of the milling and engraving machine

Composition of the CNC machine set Modelist 2020 and Modelist 3030

I Set of milled parts made of 12mm plywood for self-assembly

A set of milled parts for assembling a CNC machine with a movable table consists of:

1) Gantry stands of CNC milling machine

2) a set of milled CNC machine parts for assembling the Z axis

3) a set of milled CNC machine parts for assembling a moving table

4) a set of milled CNC machine parts for assembling stepper motor supports and spindle mounting

II Set of milling machine mechanics includes:

1. coupling for connecting the stepper motor shaft with the machine lead screw - (3 pcs.). The size of the coupling for the Modelist2030 machine with NEMA17 stepper motors is 5x5mm. For the Modelist3030 machine with Nema23 stepper motors - 6.35x8mm

2. steel linear guides for the CNC machine Modelist 3030:

16mm (4 pcs.) for X and Y axes,

12mm(2pcs) for Z axis

For the Modelist 2020 CNC machine, the diameter of the linear movement guides:

12mm(8pcs) for X, Y and Z axes.

3. linear rolling bearings for the Modelist3030 milling machine:

Linear bearings LM16UU (8 pcs.) for X and Y axes,

Linear bearings LM12UU for Z axis.

For CNC milling machine Modelist2020

Linear bearings LM12UU (12 pcs.) for X, Y and Z axes.

4. lead screws for the milling machine Modelist2020 - M12 (step 1.75mm) - (3 pcs.) with processing at d=5mm at one end and at d=8mm at the other.

For the Modelist3030 milling machine - TR12x3 trapezoidal screws (3mm pitch) - (3 pcs.) with end processing at d=8mm.

5. radial bearings for fastening the lead screws - (4 pcs.) one bearing in an aluminum block for the Z axis.

6. running nuts made of graphite-filled caprolon for the X, Y and Z axes (- 3 pcs.)

III CNC Router Electronics Set:

1. For CNC machine Modelist2020: NEMA17 stepper motors 17HS8401(size 42x48mm, torque 52N.cm , current 1.8A, phase resistance 1.8Ohm, inductance 3.2mH, shaft diameter 5mm)- 3 pcs.

For CNC machine Modelist3030: stepper motors 23HS5630 (size 57x56mm, torque 12.6kg*cm, current 3.0A, phase resistance 0.8Ohm, inductance 2.4mH, shaft diameter 6.35mm)- 3 pcs.

2. controller of stepper motors of a CNC machine using specialized microstepping drivers from Toshiba TV6560 in a closed aluminum housing

3. power supply 24 V 6.5 A for the CNC machine Modelist 2020 and 24 V 10.5 A for the CNC machine Modelist 3030

4. set of connecting wires

Assembly sequence of a CNC milling machine with a movable table.

The linear movement system of any machine tool consists of two parts: the ball bushing is the element that moves and the stationary element of the system is the linear guide or shaft (linear support). Linear bearings can be different types: bushing, split bushing, aluminum housing bushing for easy fastening, ball carriage, roller carriage, the main function of which is to bear the load, ensuring stable and accurate movement. The use of linear bearings (rolling friction) instead of sliding bushings can significantly reduce friction and use the full power of stepper motors useful work cutting

Picture 1

1 Lubricate the linear bearings of the system linear movement of a milling machine with a special lubricant (you can use Litol-24 (sold in auto parts stores)).

2 Assembling the Z axis of a CNC milling machine.

Assembly of the Z axis is described in the instructions " "

3 Assembling a CNC milling machine table, Y axis

3.1 Parts for assembling the portal, Figure 2.

1) set of milled parts

4) lead screws for the Modelist 2030 milling machine - M12 (pitch 1.75mm) with ends processed at d=8mm and d=5mm

Figure 2. Details of the milling portal desktop CNC machine

3.2 Press in the linear bearings and insert the linear bearing holders into the milled grooves, Figure 2. Insert the linear guides into the linear ball bearings.

Figure 2 Assembling a desktop CNC milling machine table

3.3 Linear bearing holders are driven into the grooves of the moving table part. The tongue-and-groove connection ensures excellent rigidity of the unit; all parts of this unit are made of 18mm plywood. Additionally, by tightening the parts with a bolted connection, we will ensure a long and reliable deadline service, to do this, through an existing hole in the plate, which serves as a guide for the drill, we drill a hole in the end of the linear bearing holder, as shown in Figure 3, a drill with a diameter of 4 mm.

Figure 3 Drilling mounting holes.

3.4 We place the table itself and fasten it through the existing holes using M4x55 screws from the kit, Figure 4 and 5.

Figure 4. Fastening the bearings of the moving table.

Figure 5. Fastening the bearings of the moving table.

3.5 Press the thrust bearings into the table frame parts. Insert the lead screw with a lead nut made of graphite-filled caprolon into the support bearings, and the linear guides into the grooves of the frame elements, Figure 6.

Figure 6. Assembling the moving table.

Fasten the frame elements with the screws from the kit. For fastening from the sides, use 3x25mm screws, Figure 7. Before screwing in the screws, be sure to drill with a 2mm diameter drill to avoid delamination of the plywood.

If the lead screw is not clamped by the parts of the base of the moving table and there is play in the screw along the axis in the support bearings, use a washer with a diameter of 8 mm, Figure 6.

Figure 7. Assembly of the tabletop machine frame.

3.6 Position the running nut centrally between the linear bearings and make holes for the screws with a 2mm drill, Figure 8, then secure the running nut with 3x20 screws from the kit. When drilling, be sure to use a stop under the lead nut to avoid bending the lead screw. .

Figure 8. Fastening the running nut.

4 Assembling the machine portal.

For assembly you will need:

1) a set of milled parts for assembling a moving table

2) steel linear guides with a diameter of 16mm (2 pieces)

3) linear bearing LM16UU(4pcs)

4) lead screws for the Modelist 2030 milling machine - M12 (pitch 1.75mm) with ends processed at d=8mm and d=5mm.

For the Modelist 3030 milling machine - TR12x3 trapezoidal screws (3mm pitch) with ends processed at d=8mm.

5. radial bearings for fastening the lead screws - (2 pcs.)

6. running nut made of graphite-filled caprolon - (- 1 pc.)

4.1 Secure the side of the portal, Figure 9.

Figure 9. Assembly of the machine portal.

4.2 Insert the lead screw with nut into the Z-axis carriage frame, Figure 10.

Figure 10. Lead screw installation.

4.3 Insert linear guides, Figure 11.

Figure 19 Fastening the lead screw “in space”.

4.4 Secure the second side of the portal, Figure 11.

Figure 11. Installation of the second side of the portal

If the lead screw is not clamped by the parts of the base of the moving table and there is play along the axis, use a washer with a diameter of 8 mm.

4.5 Install and secure the rear wall of the Z carriage, Figure 12.

Figure 12. Fastening the rear wall of the Z carriage.

4.6 Secure the caprolon running nut with 3x20 screws from the kit, Figure 13.

Figure 13. X-Axis Running Nut Attachment.

4.7 Secure the rear wall of the portal, Figure 14, using 3x25 screws from the kit.

Figure 14. Fastening the rear wall of the portal.

5 Installation of stepper motors.

To install stepper motors, use fastening parts from a set of CNC milled parts for assembling Nema23 stepper motor supports for the Modelist3030 milling machine.

Figure 15. Installation of stepper motors.

Install 5x8mm couplings to connect the motor shaft to the lead screw. Attach the stepper motors to the machine; for fastening, use the M4x55 screw from the kit, Figure 15.

6 Attach the controller to the back wall of the milling and engraving machine, and connect the motor terminal blocks to it.

7 Installation of the router.

The router is fastened to the tool neck or body. The standard neck diameter of household routers is 43mm. Spindle diameter 300W - 52mm, fastening to the body. To install, assemble the router mount, the mounting details are in Figure 16. Use the 3x30mm screw from the kit.

Figure 16 43mm spindle mount

Figure 17 Spindle with mounting on a CNC machine

When installing Dremel-like tools (engravers), you will also need additional fastening engraver body to carriage Z with a clamp, Figure 18.

Figure 18 Attaching the engraver to a milling machine.

It is possible to install a nozzle for connecting a vacuum cleaner

The article describes a homemade CNC machine. Main advantage this option machine tool - a simple method of connecting stepper motors to a computer via the LPT port.

Mechanical part

bed
The bed of our machine is made of plastic with a thickness of 11-12mm. The material is not critical, aluminum can be used, organic glass plywood and any other available material. The main parts of the frame are attached using self-tapping screws; if desired, you can additionally decorate the fastening points with glue; if you use wood, you can use PVA glue.

Calipers and guides
Steel rods with a diameter of 12mm, length 200mm (Z axis 90mm), two pieces per axis, were used as guides. The calipers are made of textolite with dimensions 25X100X45. The textolite has three through holes, two of them for guides and one for the nut. The guide parts are fastened with M6 screws. Supports X and Y in the upper part have 4 threaded holes for attaching the table and Z-axis assembly.

Caliper Z
The Z axis guides are attached to the X support through a steel plate, which is a transition plate, the dimensions of the plate are 45x100x4.

Stepper motors are mounted on fasteners, which can be made of sheet steel with a thickness of 2-3mm. The screw must be connected to the axis of the stepper motor using a flexible shaft, which can be used as rubber hose. If you use a rigid shaft, the system will not work accurately. The nut is made of brass, which is glued into the caliper.

Assembly
Assembly of a homemade CNC machine is carried out in the following sequence:

• First you need to install all the guide components in the calipers and screw them to the sidewalls, which are not first installed on the base.
• We move the caliper along the guides until we achieve smooth movement.
• Tighten the bolts, fixing the guide parts.
• We attach the caliper, guide assembly and side frame to the base; we use self-tapping screws for fastening.
• We assemble assembly Z and, together with the adapter plate, attach it to support X.
• Next, install the lead screws along with the couplings.
• We install stepper motors by connecting the motor rotor and the screw with a coupling. We pay strict attention to ensure that the lead screws rotate smoothly.

Recommendations for assembling the machine:
Nuts can also be made from cast iron; there is no need to use other materials; screws can be bought at any hardware store and cut to suit your needs. When using screws with M6x1 thread, the nut length will be 10 mm.

Machine drawings.rar

Let's move on to the second part of assembling a CNC machine with our own hands, namely the electronics.

Electronics

power unit
A 12Volt 3A unit was used as a power source. The block is designed to power stepper motors. Another voltage source of 5 Volts and a current of 0.3 A was used to power the controller microcircuits. The power supply depends on the power of the stepper motors.

Here is the calculation of the power supply. The calculation is simple - 3x2x1=6A, where 3 is the number of stepper motors used, 2 is the number of powered windings, 1 is the current in Amperes.

Controller
The control controller was assembled using only 3 555TM7 series microcircuits. The controller does not require firmware and has a fairly simple schematic diagram, thanks to this, this CNC machine can be made by a person who is not particularly versed in electronics.

Description and purpose of the LPT port connector pins.

For the experiment, a stepper motor from an old 5.25-inch was used. In the circuit, 7 bits are not used because 3 engines are used. You can hang the key to turn on the main engine (mill or drill) on it.

Driver for stepper motors
For driving stepper motor a driver is used, which is an amplifier with 4 channels. The design is implemented using only 4 transistors of the KT917 type.

You can also use serial microcircuits, for example - ULN 2004 (9 keys) with a current of 0.5-0.6A.

The vri-cnc program is used for control. Detailed description and instructions for using the program are located at.

By assembling this CNC machine with your own hands, you will become the owner of a machine capable of performing mechanical processing (drilling, milling) of plastics. Engraving on steel. Also, a homemade CNC machine can be used as a plotter; you can draw and drill printed circuit boards on it.

Based on materials from the site: vri-cnc.ru