Machine for drilling boards. Machine for drilling printed circuit boards. Continuation of the manufacturing process of the drilling machine

I wanted to assemble a machine for drilling printed circuit boards and other small things, options like a collet chuck right on the motor shaft did not suit me. Something more serious was needed, but he did not dare to start building a machine from scratch. But then a broken (after a fire) home-made micro-drilling one successfully turned up, which I took as a base for my craft, or rather restored it.

I did not photograph the initial view of the machine, the condition was very deplorable. There was a headstock, a spindle jammed in it, a spindle movement mechanism, a column and a base.

First of all, a new column was carved, the old one was severely deformed:

Screwed rubber feet onto the base:

ShB. The old m4 locking screw was broken when trying to unscrew it. I made a new handle from an M6 bolt:

At first I wanted to put a 220 volt 6 watt asynchronous, but then a 12 volt 12 watt collector was bought. It will be attached to the SB through the adapter plate:

A toggle switch is installed on it:

Pulley for the engine picked up ready:

Got a new spindle. He killed the most time, he made a hexagon with a file:

New pulley machined from ebonite:

Spindle movement mechanism:

Everyone is here:

LED lighting that turns on with the engine:

Refurbished machine:

Satisfied with the machine. I put a collector electric motor to control the speed with voltage (in the PWM plans), but the power turned out to be back to back, and I abandoned this idea. With an asynchronous machine, the machine would work many times quieter ...

In this article, we will share with you the PCB drilling machine we have developed and lay out all the materials needed to make this machine yourself. All you need is to print the parts on a 3D printer, cut the plywood with a laser and buy some standard components.

Design description

The design is based on a fairly powerful 12 volt motor from China. Complete with the engine, they also sell a cartridge, a key and a dozen drills of different diameters. Most hams just buy these motors and drill the boards with the tool in hand.
We decided to go further and, on its basis, make a full-fledged machine with open drawings for self-production.

For the linear movement of the motor, we decided to use a complete solution - polished shafts with a diameter of 8mm and linear bearings. This makes it possible to minimize backlash in the most critical place.

The base frame is made of 5mm plywood. We chose plywood because it is very cheap. Both the material and the cutting itself. On the other hand, nothing prevents (if possible) from simply cutting out all the same parts from steel. Some small details of complex shape are printed on a 3D printer.
To raise the engine to its original position, two ordinary rubber bands were used. In the upper position, the engine is turned off by itself using a microswitch.
On the reverse side, we made a place for storing the key, a small case for drills. The grooves in it have different depths, which makes it convenient to store drills with different diameters.

However, all this is easier to see on the video:

Assembly Parts

Assembly

The entire assembly process is recorded on video:

If you follow just such a sequence of actions, then it will be very easy to assemble the machine.
This is how the complete set of all components for assembly looks like:

In addition to them, the assembly will require the simplest hand tools. Screwdrivers, hex keys, pliers, wire cutters, etc.
Before starting to assemble the machine, it is desirable to process the printed parts. Remove possible sags, supports, and also go through all the holes with a drill of the appropriate diameter. Plywood parts along the cut line can stain the fumes. They can also be sanded down.
After all the parts are prepared, it is easier to start with the installation of linear bearings. They creep inside the printed parts and screw to the side walls:

Now you can assemble the plywood base. First, the side walls are installed on the base, and then the vertical wall is inserted. There is also an additional printed piece on the top that sets the width at the top. When driving screws into plywood, do not apply too much force.

In the table on the front hole, it is necessary to make a countersink so that the sunk head screw does not interfere with drilling the board. A printed fastener is also installed at the end.

Now you can start assembling the engine block. It is pressed by two parts and four screws to the movable base. When installing it, make sure that the ventilation holes remain open. It is fixed to the base with clamps. First, the shaft is threaded into the bearing, and then the clamps are snapped onto it. Also install the M3x35 screw, which will press the microswitch in the future.

The microswitch is installed on the slot with the button towards the engine. Later, its position can be calibrated.

Elastic bands are thrown over the lower part of the engine and threaded to the "horns". Their tension must be adjusted so that the engine rises to the very end.

Now you can solder all the wires. There are holes on the motor block and next to the microswitch for clamps to secure the wire. Also, this wire can be passed inside the machine and brought out from the back. Be sure to solder the wires on the microswitch to the normally closed contacts.

It remains only to put a case for drills. The top cover must be tightened tightly, and the bottom cover must be tightened very loosely, using a nut with a nylon insert for this.

This completes the build!
Of the improvements, you can glue plywood parts to increase rigidity. You can also make an engine speed controller.

Tired, in general, of drilling boards with a manual drill, so it was decided to make a small drilling machine exclusively for printed circuit boards. There are plenty of designs on the Internet, for every taste. After looking at several descriptions of such drills, I came to the decision to repeat the drilling machine based on elements from an unnecessary, old CD ROM. Of course, for the manufacture of this drilling machine, you will have to use the materials that are at hand.

From the old CD ROM, for the manufacture of a drilling machine, we take only a steel frame with two guides mounted on it and a carriage that moves along the guides. In the photo below, all this is clearly visible.

The drill motor will be mounted on the movable carriage. To mount the electric motor to the carriage, an L-shaped bracket was made from a strip of steel 2 mm thick.

We drill holes in the bracket for the motor shaft and the screws for its fastening.

In the first variant, an electric motor of the DP25-1.6-3-27 type with a supply voltage of 27 V and a power of 1.6 W was chosen for the drilling machine. Here he is in the photo:

As practice has shown, this engine is rather weak for drilling work. Its power (1.6 W) is not enough - at the slightest load, the engine simply stops.

This is what the first version of the drill with the DP25-1.6-3-27 engine looked like at the manufacturing stage:

Therefore, I had to look for another electric motor, more powerful. And the manufacture of the drill has stalled ...

Continuation of the manufacturing process of the drilling machine.

After some time, an electric motor from a disassembled faulty Canon inkjet printer fell into the hands:

There is no marking on the engine, so its power is unknown. A steel gear is mounted on the motor shaft. The shaft of this motor has a diameter of 2.3 mm. After removing the gear, a collet chuck was put on the motor shaft and several test drillings were made with a drill with a diameter of 1 mm. The result was encouraging - the “printer” engine was clearly more powerful than the DP25-1.6-3-27 engine and freely drilled textolite 3 mm thick at a supply voltage of 12 V.

Therefore, the manufacture of the drilling machine was continued ...

We fix the electric motor with the L-shaped bracket to the movable carriage:

The base of the drilling machine is made of fiberglass 10mm thick.

In the photo - blanks for the base of the machine:

To prevent the drilling machine from fidgeting on the table during drilling, rubber feet are installed on the underside:

The design of the drilling machine is of a cantilever type, that is, the supporting frame with the engine is fixed on two cantilever brackets, at some distance from the base. This is done in order to ensure that sufficiently large printed circuit boards are drilled. The design is clear from the sketch:

The working area of ​​the machine, the white LED backlight is visible:

This is how the illumination of the working area is implemented. The photo shows excessive brightness of the lighting. In fact, this is a false impression (this is a camera glare) - in reality everything looks very good:

Cantilever design allows drilling boards with a width of at least 130 mm and an unlimited (within reasonable limits) length.

Measurement of the dimensions of the working area:

The photo shows that the distance from the stop to the base of the drilling machine to the axis of the drill is 68mm, which ensures the width of the processed printed circuit boards is at least 130mm.

To feed the drill down when drilling, there is a pressure lever - visible in the photo:

To hold the drill over the printed circuit board before the drilling process, and return it to its original position after drilling, a return spring is used, which is worn on one of the guides:

The system of automatic adjustment of engine speed depending on the load.

For ease of use of the drilling machine, two variants of engine speed controllers were assembled and tested. In the original version of the drill with the DP25-1.6-3-27 electric motor, the regulator was assembled according to the scheme from the Radio magazine No. 7 for 2010:

This regulator did not want to work as expected, so it was mercilessly thrown into the trash.

For the second version of the drilling machine, based on an electric motor from a Canon inkjet printer, on ham radio cat website another circuit of the motor shaft speed controller was found:

This regulator provides the operation of the electric motor in two modes:

1. When there is no load, or, in other words, when the drill does not touch the printed circuit board, the motor shaft rotates at a reduced speed (100-200 rpm).
2. With an increase in the load on the engine, the regulator increases the speed to the maximum, thereby ensuring the normal drilling process.

The motor speed controller assembled according to this scheme worked immediately without tuning. In my case, the idle speed was about 200 rpm. At the moment the drill touches the printed circuit board, the revolutions increase to the maximum. After drilling is completed, this regulator reduces the engine speed to the minimum.

The motor speed controller was assembled on a small printed circuit board:

The KT815V transistor is equipped with a small radiator.

The regulator board is installed at the rear of the drilling machine:

Here, the resistor R3 with a nominal value of 3.9 ohms was replaced by an MLT-2 with a nominal value of 5.6 ohms.

The testing of the drilling machine was successful. The system of automatic adjustment of the frequency of rotation of the motor shaft works clearly and without fail.

A short video about the work of the drilling machine.

Of all types of drilling machines, the smallest are vertical desktop machines. The compact units are designed specifically for drilling the finest holes in small workpieces, flaring, making holes with edges, threading and riveting. This is a convenient equipment for production in small areas and with low turnover. An additional advantage of mini-machines is their low price.

Purpose of mini drilling machines

Despite the mini-sizes, desktop drilling machines fully perform their tasks, not inferior in accuracy and accuracy to large analogues.

Many drilling benches combine the function of milling and are widely used in repair shops and training centers. Most often, mini-machines are used for drilling holes in microcircuits or printed circuit boards. Micro holes with a diameter of less than a millimeter cannot be made with a drill.

Mini machine design

The main type of movement used in the design is the rotation of the drill held by the spindle. The feed movement is represented by the movement of the same drill in a vertical plane. The part is located on the worktop.

All the main components of the machine are placed in a rack located on a heavy frame - the base. Rails run along the rack to move the working head with a spindle, and inside the column there is an engine. If the possibility of switching speeds is provided, then it is realized by means of a handle. On modern models, the parameters are controlled electronically.

The executive head is lubricated with oil pumped up by a pump. The pump supplies and coolant. The executive head, as a rule, is cast from cast iron, it houses the feed and speed devices. The gearbox functions due to gears switched by the handle. The electric motor of the mini machine is powered by a household electrical network with a voltage of 220 V.

Sometimes machines are equipped with a protective screen that prevents hair or fabric from entering the chuck during rotation. The screen is usually made of transparent durable plastic, it has a removable design.

The principle of operation of the mini drilling machine

When the electric motor is started, it sets the spindle in motion. The motor power of the desktop micro model can be from 150 to 300 watts. A belt drive is more commonly used, but a gear drive is also possible in the smallest models. The speed is changed by moving the handle.

The drill is inserted into a small cam or collet chuck that holds the end of the tool firmly. The chuck is clamped with a key, the collet - automatically.

The installed drill is lowered to the part when the feed handle is pressed. It resembles a lever and is located to the right of the head. The head returns to its original place on its own, under the action of a built-in spring. On some, the drill can be locked at any point using the tightening lever.

There are drilling devices equipped with a mechanism that regulates the drilling depth. It starts like this: on the side of the part, the required depth of the future hole is marked. The chuck is lowered until the end of the drill reaches the mark. The tightening handle is tightened, holding back the further advancement of the drill.

Characteristics of mini drilling machines

Power is a parameter that affects power consumption and performance. For micro holes on printed circuit boards, a minimum power of 150 W is sufficient.

The rotation speed of the drill varies from 200 rpm to 3000. Modern mini machines are equipped with a gearbox with the ability to switch up to 12 speed modes.

The highest height of the part processed on the mini-machine is 50 cm. This figure is determined by the top point of the drilling head, which moves vertically along the rack rails. Usually the movement of the module is done manually. At a certain point, the head is fixed with a special handle.

The drill diameter indicates not so much the size of the holes as the diameter of the drills. The minimum shank diameter is 16 mm.

Table 1. Characteristics of some models of mini drilling machines

The weight and size of the bed when working with micro parts are not as important as when drilling large workpieces. But the base must be stable and strong enough to hold the tool. The surface of the worktop is perfectly flat, with several slots. Side slots are used to fix the part with clamps or vices, to place stops and rulers. And the central slot protects the drill from contact with the countertop when drilling through holes.

Drills for mini machine

In most cases, micro-boards for radio devices are made on such equipment. The board is located on fiberglass, destructive for drills. It is enough to make no more than a hundred holes and the drill must be sharpened or thrown away. It is not possible to sharpen a micro drill with a diameter of 0.5 mm with your own hands. There are drills made of hard alloys that can withstand work on fiberglass. You can find micro diameters from 0.5 to 2 millimeters, the diameter of the tail section is standard for all - 2 mm. Such a drill is enough for several thousand micro holes. But they need to work very carefully, avoiding lateral pressures that instantly break a fragile tool.

Attempts to install a micro drill in a hand drill lead to its breakage. In a drilling machine, it will regularly serve for many years.

Videos on how to make a mini drilling machine yourself: