SINING
BEAUTY AT WELLNESS
CRAFTS
KULTURA AT KASAYSAYAN
LIBANGAN
KAPALIGIRAN
PAGKAIN AT INUMIN
REVERSE ENGINEERING
AGHAM
ISPORTS
TEKNOLOHIYA
MGA WEARABLE
Convex and Concave Lenses Ground as a Pair
Rub one glass disc over another with wet grit and both change shape: the one on top goes hollow, the one beneath goes domed, and they stay a perfect fit. Grind both faces of a pair this way and the bottom disc becomes a double-convex lens, the top one a double-concave lens of the same curve. Longer work gives deeper curves and shorter focal lengths.
The picture: a double-convex lens held at arm's length shows the scene small and upside down.
Abantado
Several days per pair
Mga Tagubilin
1
1
Cut two discs
Cut two discs
Score two equal circles on the glass sheet, snap them out and nibble the edges round with grozing pliers. Fix a short wooden handle to the back of each with warm pitch.
Mga materyales para sa hakbang na ito:
Plantsa ng salamin1 piraso
Pandikit na Dagta ng Pino20 g
Tira ng matigas na kahoy1 pirasoMga kailangang kasangkapan:
Panghiwa ng salamin
Plais na panggigil ng salamin
Salaming pangkaligtasan2
2
Rough grind the first faces
Rough grind the first faces
Lay one disc face up on a firm table, wet it and sprinkle coarse grit. Push the other disc over it, face down, in short strokes, turning both a little all the time. The top one becomes concave, the bottom convex. Rinse and recharge as the grit wears.
Mga materyales para sa hakbang na ito:
Butil ng silicon carbide50 g
Tubig2 litroMga kailangang kasangkapan:
Ruler3
3
Check the curve
Check the curve
Lay a ruler across the hollow disc and measure the depth at the centre with the caliper. Keep the top disc on top to deepen the curve; swap them to flatten it.
Mga kailangang kasangkapan:
Ruler
Digital na Kalibrador 6 Pulgada4
4
Fine grind and polish
Fine grind and polish
Go through finer grits, washing everything clean between grits. Polish each face on a pitch lap pressed to the other disc's curve, with tin oxide (putty powder) and water, until clear.
Mga materyales para sa hakbang na ito:
Butil ng silicon carbide30 g
Tin oxide (stannic oxide)30 gPandikit na Dagta ng Pino100 g5
5
Turn them over, do the second faces
Turn them over, do the second faces
Move the handles to the finished faces and grind the other sides the same way, the same disc on top, to the same depth. The bottom disc is now a double-convex lens, the top one double-concave.
Mga materyales para sa hakbang na ito:
Butil ng silicon carbide60 gTin oxide (stannic oxide)20 gMga kailangang kasangkapan:
Digital na Kalibrador 6 Pulgada6
6
Find the focal length
Find the focal length
Hold the convex lens in sunlight over paper and move it until the spot is smallest; that distance is its focal length. Grind more pairs to different depths for a set of focal lengths.
Mga kailangang kasangkapan:
Ruler7
7
Focal length from the curve
Focal length from the curve
Naglo-load ng Jupyter notebook…
8
8
Limits
Limits
Which disc goes hollow is the mirror makers' rule (Sky & Telescope, Stellafane); the lens formula is from Wikipedia. Window glass is not optical glass: expect some colour fringes and bubbles.
Mga Materyales
6- 1 pirasoPlaceholder
- Placeholder
- 1 pirasoPlaceholder
- Placeholder
- 2 litroPlaceholder
- Placeholder
Ang blueprint na ito ay gumagawa ng
Kaugnay na Blueprint
Ang mga blueprint na ito ay nagbabahagi ng kaalaman — mga teknik, materyales, o prinsipyo
CC0 Pampublikong Domain
Ang blueprint na ito ay inilabas sa ilalim ng CC0. Malaya kang kumopya, magbago, mamahagi, at gumamit nang walang pahintulot.
Suportahan ang Maker sa pamamagitan ng pagbili ng mga produkto sa kanilang Blueprint Komisyon ng Maker itinakda ng mga Vendor, o lumikha ng bagong bersyon ng Blueprint na ito at isama bilang koneksyon sa iyong Blueprint upang ibahagi ang kita.