For myself, just recently, for a couple of nights I made such a mini drill, which is devoid of all the above disadvantages.
The only thing I had to buy to make this homemade - This is a mini cartridge on Aliexpress, a month ago it cost 476 rubles. (like this)
Further:
1. I, like every master, found in the reserves an engine from some copier, which was thrown into the scrap.
The engine caught a power of 24 watts and powered by 12 volts. It could be powered from a 12 volt power supply and 2 amperes. (In principle, this is not critical, the engine can be taken from any other mechanism, for example, from a video cassette recorder, there are quite powerful engines (there are two of them). Of course, there will be other power and power parameters, but for a micro drill, awesome power and not needed.
2. The cartridge from Aliexpress came to me with a cone with an inner diameter of 3.17 mm, which perfectly fit the shaft of my engine.
3. Having collected the engine, the conical sleeve and the boss, I almost got a finished drill, but all this, to put it mildly, garbage, and, roughly speaking, complete garbage.
4.Next, I decided to upgrade this my device.
5. I asked my grandchildren for all plastic toy pistols and machine guns that were no longer of interest to them, in order to cut off the handle of this toy and attach it to my “drill”.
6. Having received several options of “not needed FIGS.” Pistols and machine guns (naturally, toys), I found a suitable pen option for my future mini drill.
7.And now an important detail. About three months ago, they brought me a faulty screwdriver for free. He did not have a battery and, to put it mildly, rotted the engine. I think they found him somewhere in the trash, but the control button was working, becauseIt is made of plastic.
8. This control button, I naturally took out and saved, and threw everything else.
9. So, when I decided to upgrade my device (see section 4), I remembered about this button, which can adjust the engine speed and switch to reverse, i.e. change the direction of rotation of the engine.
10. Basically, that's it. Having disassembled the handle of the toy gun, I placed in it a control button from the screwdriver and a connector for connecting the power of our mini-drill, having previously cut out the necessary holes for the button and connector.
It turned out like this:
11. Soldered two wires to the power connector, observing the polarity, and brought out two wires for connecting to the motor. Everything fit cool.
12. Further there was a need to securely attach the engine to the handle.
a) On each (almost every) engine there is a clamp (ring) in the size of the engine. Here we will use it.
b) Next, we need to solder two thin iron plates to this clamp (of course, having previously removed it from the engine) so that they fit exactly into the inside of the selected handle of the plastic gun. (like this)
Difficult, but real. There are subtleties, I can tell. Write to the Lichka.
c) Next, insert the fitted clamp with plates into the handle and drill the mounting holes for screws or screws, but no more than M3.
d) Insert our engine into the clamp, center it to solder the power and fix it in the handle with screws or screws.
13. We solder the power to the motor, observing the polarity.
14. We work.
ALL!!! Praise your friends.
P.S. My mini-drill, with drill bits from 1.0 mm to 3.0 mm, drills almost any material, from wood to iron with a thickness of 2-3 mm, saws (with wood files) any plastic and plastic, cuts (metal with diamond blades) any metal .
Yes, I forgot to say that the beating of my mini-drill is practically zero, so working with her, believe me, is a pleasure.
(Naturally, working with such an instrument can only be done by performing very (well, maybe not very) exact, delicate, jewelry work).
Drilling a concrete wall to hang a carpet is not recommended!
Who cares, I will post a video showing the work of my "Crocodile" - that's what I called it.
Sincerely, Mikhail.
I wish all the masters GOOD LUCK!