On this resource, many people who are engaged in electronics and independently manufacture printed circuit boards. And each of them will say that drilling a printed circuit board is a pain. Small holes have to be drilled by hundreds and each independently solves this problem for themselves.
In this article I want to present to your attention an open project of a drilling machine that everyone can collect himself and he will not need to look for CD-drives or subject Tables for the microscope.
Description of the construction
The design is based on a rather powerful 12-volt engine from China. Complete with the engine, they also sell a cartridge, a key and a dozen drills of different diameters. Most radio amateurs simply buy these engines and drill the cards while holding the instrument in their hands.
I decided to go further and use it as a basis for making a full machine for such engines with open drawings for independent production.
For linear displacement of the engine, I decided to use polished shafts of 8mm in diameter and linear bearings. This makes it possible to minimize backlashes in the most critical place. These shafts can be found in older printers or bought. Linear bearings are also widely distributed and available, as they are used in 3D printers.
The main frame is made of plywood 5mm thick. Plywood I chose because it is very cheap. Both the material and the cutting itself. On the other hand, nothing prevents (if there is a possibility) just to cut all the same details from steel or plexiglass. Some small details of a complex shape are printed on a 3D printer.
Two conventional office rubbers were used to raise the engine to its original position. In the upper position, the motor itself is turned off by means of a microswitch.
On the reverse side, I provided a place for the keying of the key and a small pencil case for drills. The grooves in it have different depths, which makes it convenient to store drills with different diameters.
But all this is easier to see once on video:
There is a small inaccuracy on it. At that moment, I got a defective engine. In fact, from 12V they consume at idle 0.2-0.3A, and not two, as the video says.
- The engine with Cartridge and collet. On the one hand, the jaw chuck is very convenient, but on the other hand it is much more massive than the collet jaw, that is, it is often subject to beatings and very often they have to be balanced further.
- Plywood details. A link to files for laser cutting in the format dwg (prepared in NanoCAD) can be downloaded at the end of the article. It's enough just to find a company that deals with laser cutting materials and transfer the downloaded file to them. I note separately that the thickness of plywood can vary from case to case. I come across sheets that are slightly thinner than 5mm, so I made slots at 4.8mm.
- The details printed on the 3D printer. A link to files for printing parts in stl-format can also be found at the end of the article
- Polished shafts with a diameter of 8mm and a length of 75mm – 2pcs. Here is a link to the seller with the lowest price per 1m I saw
- Linear bearings on 8mm LM8UU – 2pcs
- Microswitch KMSW-14
- Screw M2x16 – 2pcs
- Screw M3x40 w / w – 5 pieces
- The screw M3x35 slot – 1 piece
- Screw M3x30 w / w – 8 pieces
- The screw M3x30 w / w with the head vpota – 1 pc
- The screw M3x20 w / w – 2pcs
- Screw M3x14 w / w – 11 pieces
- Screw M4x60 slot – 1 piece
- Bolt M8x80 – 1pc
- Gadget M2 – 2pcs
- M3 square nut – 11 pieces
- Nut M3 – 13pcs
- Nut M3 with a nylon ring – 1 piece
- M4 nut – 2 pieces
- M4 square nut – 1 piece
- M8 nut – 1 piece
- Washer M2 – 4 pieces
- Washer M3 – 10 pieces
- Washer M3 increased – 26pcs
- Washer M3 checkered – 17pcs
- Washer M4 – 2pcs
- Washer M8 – 2 pieces
- Washer M8 Crowned – 1 piece
- Set of mounting wires
- Set of heat-shrink tubes
- Clamps 2.5 x 50mm – 6pcs
Assembling of the
The entire process is detailed on the video:
If you follow this sequence of steps, then it will be very easy to assemble the machine.
This is how the complete set of all components for assembly looks
In addition to them, a simple hand tool is required for assembly. Screwdrivers, hex keys, pliers, pliers, etc.
Before starting to assemble the machine, it is desirable to process the printed parts. Remove possible influxes, supports, and also pass all holes with a drill of the appropriate diameter. Plywood parts along the cutting line can smudge. They can also be treated with sandpaper.
After all the details are prepared to start easier with the installation of linear bearings. They creep inside the printed parts and are screwed to the side walls:
Next, a handle with a pinion is installed. The shaft is inserted into the large hole, the base of the handle is mounted on it and all of this is pulled together by a bolt of 8mm. The very handle is a screw on the M4:
Now you can collect a plywood base. First, the side walls are installed on the base, and then a vertical wall is inserted. In the upper part there is also an additional printed part that sets the width at the top. When screwing screws into plywood, do not apply too much force.
In the table at the front opening, Make a countersink, so that the screw with the head vpota does not prevent drilling the board. A printed fastener is also installed from the end.
Now you can start assembling the engine block. It is pressed with two parts and four screws to the movable base. When installing it, make sure that the ventilation holes remain open. On the base, it is fixed with clamps. First, the shaft is threaded into the bearing, and then the clamps snap into place. Also install a screw M3x35, which in the future will click on the microswitch.
The microswitch is mounted on the slot with the button towards the engine. Later, his position can be calibrated.
Erasers are thrown on the lower part of the engine and are passed to the "horns". Their tension must be adjusted so that the engine rises to the very end.
Now you can solder all the wires. On the engine block and next to the microswitch there are holes for the clamps to fix the wire. Also, this wire can be held inside the machine and removed from the back. Be sure to solder the wires on the microswitch to the normally closed contacts.
It remains only to put a pencil case for drills. The top cover must be clamped tightly, and the lower one must be twisted very weakly, using a nut with a nylon insert for this purpose.
The assembly is over!
Other people who have already assembled such a machine have made many proposals. I, if you will allow me, will comb the main of them, leaving them in the author's form:
- By the way, those who had never worked with such details would like to remind that plastic from 3D printers is afraid of heating. Therefore, you should be careful here – do not go through holes in such details with a high-speed drill or Dremel. Handles, handles ….
- I would recommend installing the microswitch at the earliest stage of the assembly, since it is still necessary to screw it to the already assembled frame, there is very little free space. It would also be advisable to advise the craftsmen, in advance, at least to tamper the contacts of the microswitch (or, even better, to solder the wires to them in advance and protect the soldering points with pieces of heat-shrink tubing), so that they can not damage the plywood parts of the product after soldering.
- I was apparently lucky and the cartridge on the shaft was not centered, which led to a serious vibration and the hum of the whole machine. It was possible to correct by centering "pliers", but this is not a good option. Since the axis of the rotor is bent, and it is no longer possible to remove the cartridge, there are fears that I will pull this very axis entirely.
- Tighten the screws with lock washers as follows. Tighten the screw until the lock closes (straightened). Then turn the screwdriver 90 degrees and stop.
- Many advise to attach to it the regulator of revolutions according to Savov's scheme. It turns the engine slowly when there is no load, and increases the speed at the appearance of the load.
Links for downloading
All files are collected in the main article about the project on my site. There you can download everything from direct links without registration and other problems.