When making homemade grinders, sharpening machines or other homemade products, you need to drill the motor shaft. This is not a problem if you have a lathe, but with a hand tool it is extremely difficult to make a hole straight. In most cases, it turns out skewed. However, with a certain procedure, alignment can still be achieved. Let's look at an example of drilling for an M6 bolt.
Required tools:
- screwdriver;
- set of drills 3 mm; 4.5 mm, 5 mm;
- M6 tap;
- oiler
How to drill a shaft
To prevent the hole from going sideways inside the shaft, you need to drill with the engine running. The motor is secured so that its shaft can be easily reached. It is located either strictly vertically or horizontally.
It is important that the shaft rotates counterclockwise when drilling. Otherwise, the drill simply will not work. To do this, on a synchronous motor you need to disconnect the capacitor, turn on the power and turn the shaft counterclockwise by hand. If there are left-handed drills, the motor starts in normal mode.
After this, take a screwdriver with a drill smaller than the diameter of the hole for threading by 2 mm.The tool is set to the tightening mode and the minimum settings for ratchet operation. This is necessary so that the drill does not bite inside, which will create a practically unsolvable problem.
There is usually a recess in the center of the shaft into which the tip of the drill is inserted. You need to drill at low speed, let the motor itself do the main work. Periodically, the drill should be lubricated with oil and chips removed.
After drilling with the first drill, the hole is slightly larger in diameter than the tool used.
Next it should be expanded. For the second pass you need to take a 4.5 mm drill. It is also important to work carefully at the minimum speed of the screwdriver and with periodic lubrication with oil.
In an expanded hole, the gap around the 4.5 mm drill will already be minimal. This is because the tool worked with less runout.
The final drilling is done with a drill of the final diameter. In this case, a hole for an M6 thread is required, so a 5 mm drill is used. Since it is only 0.5 mm larger than the previous hole, almost perfect alignment is achieved between the rotation of the shaft and the screwdriver chuck.
Next, all that remains is to cut the M6 thread with a tap. The main thing is not to rush when working. There is no need to make deep passes at once. The drill should be removed and constantly lubricated. That way it won't break. Also, you can’t put pressure on it, it will do everything on its own.
