Old alarm clocks and many doorbells and telephones emit a signal due to the blows of “hammer” metal hemisphere of the bell.
If you are annoying it’s pretty sharp rattling, stick a bell in place of hitting it square of adhesive tape or medical adhesive tape device will beep “whisper”.
.
Recommend to read
THE BALL-PRAGONET
Making such a toy, you not only will learn to work with a hacksaw, a drill and other simple tools, but you will get a great shell for sports training. Look at the drawing....
RETURNED TO THE SKY
Sixty years have passed since then, as removed from service legendary fighter I-16. For over half a century don't fly "flying tank" Il-2. But how do you want to see them in the sky! In...