All flashlights have a reflector giving a wide enough beam of light. But if you want a point — for example, the light pointer of the lecturer? Narrow beam, as if from hidden lamps in detective films, will Give a simple nozzle. For its production will need a plastic Cup suitable diameter and lens from diascope to view the slides. In the bottom of the Cup making the hole, on which the acetone is glued to the plastic rim of the eyepiece.
Recommend to read
THE GRIP ON THE LEASH
Bench drilling machines (such as NA-10, NA-12), as a rule, is at any station of young technicians in every school workshop. There are some in our school (I work as a teacher). And once a...
CHANGE ROUND TO OVAL
A letter from our reader V. Zasyadko prompted the idea to go back to the old idea of replacing the round sprocket of the bike Ellipso, which leads to the alignment torque generated by...
