The easiest way to drill PCBs is by holding a motor with a drill chuck attached in your hands. At the same time, drills broke more than once, and every radio amateur scolded himself in his thoughts, and the next time when making a “signet” he definitely wanted to change something in this process. Everyone decides for themselves whether to make something from improvised means or purchase a ready-made one. It all depends on the place of residence of the radio amateur. For example, in rural areas far from large centers, the best way out of this situation is to make a machine yourself.
The main requirement for such a machine is that it cope with its task, and its manufacture does not require complex turning parts, since not everyone has the opportunity to have access to a lathe. I offer you a simple design of a drilling machine for a home workshop, which I saw on the Internet, and which will not be difficult to repeat at home. Unfortunately, I don’t know the author of this design, and if he turns up, I will be happy to indicate his name here and express my gratitude for the simple design. Machine dimensions; base 140x90 mm, height 150 mm. It copes with its task quite well and takes up very little space on the desktop. With such dimensions, it allows you to drill holes in boards up to 150-170 mm wide. (the length of the board is not limited), which is quite sufficient in amateur radio practice.
The base of the machine is made of any available material, with a thickness of at least 6-8 mm. Can be made from textolite, getinaks, metal, plywood. If you take plywood, it is better to have a thickness of at least 10 mm. The dimensions of the base are indicated above, but you can change these dimensions for your needs, both the base and other parts. In the future I will simply indicate my sizes. The entire structure is assembled on a U-shaped stand, for which it is necessary to take thick material so that the entire structure does not spring and has sufficient strength.
This design uses a metal strip 25 mm wide. and 4-5mm thick. Its total length is 140-150 mm. Bent in a U-shape, attachment to the base 30mm, height 40mm and the remaining length is 70-80mm.
Three holes are drilled in the rack, one at the bottom for attaching it to the base, and two at the top for vertical pins. Long pin 100 mm long, diameter 5 mm.
A spring is placed on a long pin. The short pin is threaded on both sides, for attaching the pin to the stand and at the top for the locknut. The moving part with the motor attached to it moves on these two pins. The spring must be so rigid that it lifts the weight of the moving part with the engine.
The moving part is made of a metal strip, at least 1.5-2.0 mm thick and 20 mm wide. The total length of the strip is 100 mm, the fold dimensions are 20x40x40 mm. A through hole is drilled for the thick pin and a hole for the thin pin. By the way, the pins can be made of the same diameter, the main thing is that the material is sufficiently rigid, for example, shafts from dot-matrix printers. The clamp for mounting the engine - according to the diameter of the existing engine, is made of sheet aluminum. I have an engine used for the DPM-30 machine.
To power such an engine, a 12-volt source is sufficient, and most importantly, it is necessary to make a motor control circuit for it. This is so that without load the motor rotates slowly and when the drill touches the board, it starts working at full power. There are as many such schemes as you like, for example you can choose from here. In my opinion, it is better to collect the latter.
Although, to be honest, I still use it myself without such a circuit, I have an adjustable power supply and during pauses I simply remove the voltage.
Lever with holder, the design is clearly visible in the photographs. We fix it in the holder and attach it to the rack.
We secure the moving part and lock it with a nut.
Well, that’s it, all that remains is to secure this entire structure to the base, secure the available motor with a clamp on the moving part, secure the drill and start working.
Yes, I “confiscated” a used cork stand for hot dishes from my wife, and cut out an attachment for printed circuit boards from it and glued it to the base, so that when drilling the signets, the drill would not reach the base.
Good luck to everyone in your work and all the best!
P.S. Yes, I also want to say a little about drills.
Don’t be lazy and find special drills for drilling fiberglass for your work. Our drills are made of VK6M alloy; they usually have a shank of the same diameter and the drills themselves are 0.7-2.0. The holes made by them are much more decent than those made by ordinary drills and they look like this;
Imported ones also look something like this.
This is not for the sake of advertising, but for the convenience and pleasure of work.
I first drilled boards with ordinary drills (for metal), which after a few holes become very dull, and after a dozen they become completely unusable, then I found out about such drills, found them and purchased them (their price, by the way, is in the range of 20-50 re) . I tried to drill with them - heaven and earth. According to reviews from radio amateurs, one drill can be used to drill boards for several years (several thousand holes) until you break it due to careless handling.
But, these drills are not suitable for hand drills. When you try to make a hole with them, it instantly breaks (due to the slightest distortion). That is, they can only be drilled reliably and for a long time in a machine, and the chuck should not have any runout, and the drill clamped by it should be well centered. Then their durability is guaranteed.
In this article, we will share with you the machine we have developed for drilling printed circuit boards and lay out all the materials necessary for making this machine yourself. All you need is to 3D print the parts, laser cut the plywood and purchase some standard components.
Description of design
The design is based on a fairly powerful 12-volt motor from China. Included with the engine, they also sell a cartridge, a wrench and a dozen drills of different diameters. Most hams simply buy these motors and drill the boards while holding the tool in their hands.
We decided to go further and, based on it, make a full-fledged machine with open drawings for independent production.
For linear movement of the motor, we decided to use a full-fledged solution - polished shafts with a diameter of 8 mm and linear bearings. This makes it possible to minimize backlash in the most critical place.
The main frame is made of 5mm thick 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 parts with complex shapes are 3D printed.
To lift the engine to its original position, two ordinary rubber bands were used. In the upper position, the motor switches itself off using a microswitch.
On the back side we made a place to store 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, it’s easier to see all this in the video:
Parts for assembly
Assembly
The entire assembly process is recorded on video:
If you follow exactly this sequence of actions, then assembling the machine will be very simple.
This is what a complete set of all components for assembly looks like:
In addition to them, assembly will require a simple hand tool. Screwdrivers, hex keys, pliers, wire cutters, etc.
Before starting to assemble the machine, it is advisable to process the printed parts. Remove possible sagging, supports, and also go through all holes with a drill of the appropriate diameter. Plywood parts along the cut line may become stained with smoke. They can also be sanded with sandpaper.
Once all the parts are prepared, it's easier to start by installing the linear bearings. They creep inside the printed parts and are screwed 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 at the top that defines the width at the top. When driving screws into plywood, do not use too much force.
It is necessary to make a countersink in the table on the front hole so that the head screw does not interfere with drilling the board. A printed fastener is also installed at the end.
Now you can begin assembling the engine block. It is pressed with two parts and four screws to the movable base. When installing it, you must ensure that the ventilation holes remain open. It is secured to the base using clamps. First, the shaft is threaded into the bearing, and then clamps are snapped onto it. Also install an M3x35 screw, which in the future will press the microswitch.
The microswitch is installed on the slot with a button towards the engine. Later its position can be calibrated.
The rubber bands are placed on the bottom of the engine and threaded through 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 engine block and next to the microswitch for clamps to secure the wire. This wire can also be routed inside the machine and brought out from the back. Make sure you solder the wires on the microswitch to the normally closed contacts.
All that remains is to install the pencil case for the drills. The top cover must be clamped firmly, and the bottom cover must be tightened very loosely, using a nut with a nylon insert for this.
This completes the assembly!
As an improvement, you can glue the plywood parts to increase rigidity. You can also make an engine speed controller.
After reading articles about the achievements of forum members in the field of machine tool building (well done, guys!) with mention of CD drive units, I went into the trash bin and pulled out a dead CD drive TEAC.
Looking at the carriage holding the laser module, I immediately realized that this is an almost finished drilling head drive unit!
Inside the CD drive
The accuracy of the feed is beyond doubt - after all THE LASER ITSELF positioned! But for greater reliability (after all, the drilling head is heavier than the laser), another similar carriage was needed. Fortunately, there was an identical (or almost) one lying nearby. TEAC. Mechanically, they seem to have a standard. In short, we remove the carriage from it, install it next to the existing one, and this is what happened:
The working stroke of this tandem is about 10 mm - quite enough. You can, of course, file something down in order to increase the drill stroke by bringing the carriages closer together, but there is no point - the machine is only intended for drilling circuit boards (at least for me).
PS. It was not possible to dismantle one laser - so you can safely write “laser” in the name of the machine!
Now you need to think about the bed. Let's look at the chassis of the same drive:
We cut along the red lines, trim the corners to taste. The cut along the green lines will be useful to us later. Don't forget to remove burrs - sources of injury. As a result, we get two identical, but symmetrical brackets:
I didn’t check the angles - after all TEAC- a decent company. Having drilled the necessary holes, we assemble the frame, focusing on the shelves and corners available on the parts:
View from the back (from inside the machine):
The arrows indicate the places where the parts mate. These shelves and corners make assembly so much easier! Don't forget to install spring washers under the nuts - it's a machine, after all! Vibration…
Now you need to think about the drill head. At first I wanted to adapt my DPR-12-2 27V 5000 rpm(It was for him that the second carriage was fenced, and, as it turned out, not in vain!). But my motor on this design looked like a bull in a china shop!
Study 1
There were two DC motors in the drive.First I removed the carriage drive motor (visible in Fig. 1). A plastic bushing is pressed onto its shaft, which includes a gear and a perforated disk. Having connected 12V to the contacts, I tried to stop the shaft with my fingers - I almost tore off the skin, but the motor still did not stop. The diameter of the bushing in the space free from the gear is slightly more than 3 mm. Can be adjusted to fit a collet chuck! Having carefully cut off the gear and adjusted the diameter of the bushing (right with the engine running), I try to press the cartridge onto the bushing:
To be honest, it didn’t work out for me - I got beats and vibration. I tried using locking ones instead of screws (without heads) - almost the same result. Most likely, this is due to the mass ratio of the motor and cartridge. Maybe someone will succeed - the motor clearly deserves attention.
Then the ejector drive motor caught my attention. I had a collet chuck from a Soviet drill - you probably remember - a small motor with a thin shaft and a hefty power adapter. So, the chuck from this drill almost matches the diameter of the shaft in its seat. I wound one layer of copper foil onto the shaft - and the cartridge had to be pressed in a vice (being careful). In general, I think a good turner should be able to cope with this task, but I was just lucky.
Let's continue. From the remains of the LED chassis (see Fig. 2, green lines) we make a suitable bracket and install the drilling head on it. We attach the unit with screws to the carriages in place:
So, the bed is ready!
Need a base for the machine. Without a base, it’s some kind of drill or something...
PS. When I was disassembling the SD, the thought flashed through to use its body as a base - the result would be almost complete unification!
But! Firstly, the toad crushed it, and secondly (also important) - if you mount the frame directly on the body, you need to drill a hole in the body for the drill to exit. And if there is a hole (even a small one!), then within a week the body will be clogged with chips. In order not to drill, we would have to install a false table on the body, in which this very hole would be drilled. Then why do we need a building? In short, the toad won. I'll tell you a secret - I stole a cutting board from the kitchen (there's even a hole in it - hang the machine on a nail). A plate made of textolite-getinax with a thickness of about 8-12 mm is probably best suited. Here it’s who has what. Although remounting the machine on a new base - ugh! - Re-tighten 4 screws.
So, we mount the frame on the kitchen base:
Because We will drill not only small boards, but also ensure a gap between the frame and the base. We provide it by installing the frame with screws:
I couldn’t think of anything smarter to ensure clearance than to screw one M4 nut onto the mounting screws. You can use washers - in short, the size of the gap can be adjusted - the main thing is that the board moves freely in this gap. The working field (the distance from the center of the drill to the nearest support) is 80 mm - enough for my purposes (after all, if it doesn’t fit, you can drill the center of the board manually). And this is not a dogma - you can organize the mounting of the machine differently. Or you can actually dismantle the machine from the frame and use it to crawl around the board...
Red arrows indicate the mounting locations of the frame. I also thought about mounting the jibs - they are schematically drawn in blue - but it turned out that it was not necessary. Green - the size of the working field.
You can already drill by removing the upper motor and moving the carriages with your fingers.
The head carriages move smoothly.
But this very engine haunts me. This is an electric supply with a gearbox! Just install the limit switches and press the pedal button.
Study 2
Having connected 12V to the drilling head, I try to apply voltage to the carriage drive motor using the “poke” method. It doesn't work with haste. If 12V is supplied to the carriage drive motor, the board does not have time to drill and the mechanical protections on the carriages begin to click. If the voltage is lower, it is drilled, but not always. The carriage drive motor must have low speeds and at the same time sufficient power. I think by using PWM on the carriage drive motor, you can try to achieve success. We'll put it off for now. Maybe someone will have some ideas.
We cut out the red one and get a bracket. I don’t particularly describe it, it’s clear from the photo:
We install LEDs “in weight” on their own terminals to adjust the backlight zone.
Of all types of drilling machines, the smallest are vertical tabletop machines. Compact devices are designed specifically for drilling very thin holes in small workpieces, flaring, making holes with edges, cutting threads and rivets. This is 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 their mini size, tabletop drilling machines fully perform their tasks, not inferior in accuracy and precision to large analogues.
Many tabletop drilling machines combine a milling function 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 the vertical plane. The part is located on the worktop.
All main components of the machine are placed in a rack located on a heavy frame - the base. Rails run along the stand to move the working head with a spindle, and inside the column is a motor. If it is possible to change speeds, it is implemented using a handle. On modern models, the parameters are controlled electronically.
The actuator head is lubricated with oil pumped up by a pump. The pump also supplies the coolant. The actuating head, as a rule, is cast from cast iron, and contains feed and speed devices. The gearbox operates through gears switched by hand. The electric motor of the mini machine operates from a household electrical network with a voltage of 220 V.
Sometimes machines are equipped with a protective screen to prevent hair or fabric from getting into the chuck during rotation. The screen is usually made of transparent, durable plastic and has a removable design.
Operating principle of mini drilling machine
When the electric motor starts, it drives the spindle. The power of the electric motor of the desktop micro-model can range from 150 to 300 W. A belt drive is most often used, but in the smallest models a gear drive is also possible. The speed is changed by moving the handle.
The drill bit is inserted into a small jaw or collet chuck that holds the end of the tool tightly. The jaw chuck is clamped with a key, the collet chuck is clamped automatically.
The installed drill is lowered towards the workpiece 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 independently, under the action of a built-in spring. On some, the drill can be locked at any point using a tightening lever.
There are drilling devices equipped with a mechanism that regulates the drilling depth. It starts like this: the required depth of the future hole is marked on the side of the part. The chuck is lowered until the end of the drill reaches the mark. The tightening handle is tightened, restraining further advancement of the drill.
Characteristics of mini drilling machines
Power is a parameter that affects energy 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 maximum height of a part processed on a mini-machine is 50 cm. This indicator is determined by the top point of the drilling head, which moves vertically along the rails of the rack. Usually the module is moved manually. At a certain point the head is secured with a special handle.
The drilling diameter indicates not so much the size of the holes as the diameter of the drills. The minimum shank diameter is 16 mm.
| Machine brand | Power, W | Revolutions, rpm | Number of speeds | Chuck diameter, mm | Vertical stroke, mm | Weight, kg |
| Corvette 411 | 150 | 100-5000 | 2 | 6 | 40 | 6 |
| Bison ZSS-350 | 350 | 580 — 2650 | 5 | 13 | 50 | 16,4 |
| 350 | 580 — 2650 | 5 | 16 | 50 | 18 | |
| Kraton DM-13 | 350 | 620 — 2620 | 5 | 13 | 50 | 17 |
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. The side slots are used for fixing the part using clamps or vices, placing stops and rulers. And the central slot protects the drill from contact with the tabletop when drilling through holes.
Drills for mini machine
In most cases, microboards for radio devices are made using such equipment. The board is located on fiberglass, which is destructive to 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. This drill is enough for several thousand micro holes. But they need to work very carefully, avoiding lateral pressure, which instantly breaks the fragile instrument.
Attempts to install a micro drill in a hand drill lead to its failure. It will serve well in a drilling machine for many years.
Videos on how to make a mini drill yourself:
Since the invention of the machine, the production of various mechanisms and parts has advanced significantly. Now they are real assistants to people who process metals, plastics, wood and other materials.
These devices allow you to perform quite specific work at a higher quality level.
This type of equipment also includes a homemade drilling machine for printed circuit boards, used in radio electronics and related fields.
PCB machines
Printed circuit boards are the basis of all microcircuits. It is designed for mechanical and electrical connection of various electronic components.
Such boards are made from dielectric material, onto which all microelectronic elements are subsequently installed.
Transistors, thyristors and other microelectronics are installed on the boards, i.e. a large number of miniature details that are difficult to see with the naked eye.
Additional elements are added to the simplest boards by screwing them together and then soldering them. Naturally, in order to screw the elements, you need to drill holes in the board. It is necessary to make such holes with pinpoint precision. A discrepancy of even a couple of hundred microns can be very noticeable or lead to product failure if you are going to place a large number of electronic components on the board.
Radio electronics hobbyists often make printed circuit boards that require drilling a large number of small-diameter holes. Drilling small holes, 0.5-1.0 mm in diameter, using a classic tabletop drill, drill or screwdriver is not a very convenient task, during which it is easy to break the drill. As a result, it is advisable to drill micro-holes in printed circuit boards using a specialized mini drilling machine, using carbide drills with a diameter of 0.7-0.8 mm.
Using a mini drilling machine greatly simplifies the work, making it almost mechanical, thereby increasing labor productivity. At the same time, the design is not particularly complex; for these reasons, many prefer to assemble them with their own hands.
This homemade mini drilling machine can drill both printed circuit boards and any other workpieces, however, due to the design of the machine, there are restrictions on the depth of the hole.
Design
At first glance, the scheme seems complicated, however, it is not. In fact, the mini machine is not very different from the classic one; it is smaller in size with some nuances in the design layout.
Since this equipment is not large in size, it should be considered as a desktop one.
A homemade version of equipment is usually slightly larger than a purchased one, due to the fact that when assembling it yourself, it is not always possible to optimize the design by selecting small-sized components. But even in this case, the homemade machine will have small dimensions and weight no more than 5 kg.
Assembly video
Elements of a drilling machine
To assemble a mini device with your own hands, you will need the following:
- Bed;
- Transitional stabilizing frame;
- Bar for moving;
- Shock absorber;
- Height adjuster handle;
- Engine mount;
- Engine;
- Collet (or cartridge);
- Adapters.
It is worth noting that we are describing a homemade mini drilling machine, assembled from improvised materials with your own hands. The factory design is distinguished by the use of specialized components that are almost impossible to make yourself.
The basis of a mini drilling unit, like any other, is the frame. It serves as the base on which all the nodes will be held. The frame can be a handy device, for example: the skeleton of a microscope; stand for linear measurements with a digital indicator.
Or you can make it yourself, for example, a light wooden frame - by connecting the boards with self-tapping screws, or a heavy and stable one - by welding a steel profile to a metal sheet. It is better when the weight of the frame is higher than the main weight of the other components, this increases the stability of the unit and reduces its vibration during operation.
Electric motors from cassette recorders, printers, disk drives and other office equipment can serve as motors. A chuck or collets are selected as a fastening for drills. However, the chuck is more universal, while the collet allows for the installation of drills of only certain sizes.
Another interesting scheme based on spare parts from a CD-ROM and a hair dryer with automatic adjustment of the engine speed depending on the load.
Homemade bed
When making a steel frame with your own hands, you can screw legs under it to fix its position.
The stabilizing frame can be made, for example, from a lath or angle, but it is better to use steel.
You can choose any type of bar for moving that is most convenient, but it is better to combine it with a shock absorber. In some cases, the shock absorber itself may be such a bar. The functions of these parts are to vertically move the equipment during operation.
You can make a shock absorber yourself, remove sliding slats from office furniture, or purchase them in a store.
The height adjuster handle is installed on the body, stabilizing the rail or shock absorber.
The engine mount is mounted to a stabilizing frame, which can be, for example, a simple wooden block. It is needed to bring the engine to the required distance and securely fix it.
The engine is then mounted directly onto the mount.
A chuck or collets are directly attached to the motor, to which adapters used to install drills are attached. Adapters are selected individually, depending on the motor shaft, its power, drill type, etc.
In conclusion, we can say that the assembled mini drilling machine can be constantly modified during operation. For example, you can stick an LED strip on the chuck to illuminate the samples being drilled.
A note about drilling machines
The machine is a single, rigidly fixed structure, and consists of basic elements: a base, a stand of various adapters, fastenings, an electric motor and other elements.
Its task is to increase the accuracy of tool processing and reduce the labor intensity of work: it makes human labor as easy as possible (for example, when processing hard materials such as metals), and reduces the influence of the human factor in production.
Conventional inexpensive mini machines move mainly along one axis, for example, drilling machines only from top to bottom.
More expensive ones can move in several planes, at least two, vertical and horizontal. Such models can already be automatic or semi-automatic.