IṢẸ́ ỌNÀ
ẸWÀ ÀTI ÌLERA
IṢẸ́ ỌWỌ́
ÀṢÀ ÀTI ÌTÀN
ÌṢERÉ
ÀYÍKÁ
OÚNJẸ ÀTI OHUN MÍMU
REVERSE ENGINEERING
SÁYẸ́ǸSÌ
ERÉ ÌDÁRAYÁ
ÌMỌ̀-Ẹ̀RỌ
ÀWỌN OHUN WÍWỌ̀
Magnifying Glass from a Hand-Ground Lens
A magnifying glass is a convex lens in a frame with a handle. A typical one has a focal length of 25 cm, an optical power of 4 dioptres, and is sold as "2×": its magnifying power is 0.25 m × 4 + 1 = 2 for an eye whose near point is 25 cm. Here the lens is ground plano-convex from crown glass (refractive index about 1.52). For a plano-convex lens the focal length is R / (n − 1), so a 25 cm focal length needs a curve of radius about 13 cm. The lens is then set in a turned wooden ring with a handle; those sizes are ours.
Ilọsíwájú
2–3 days
Ìlànà
1
1
Grind the lens
Grind the lens
Following the lens-grinding blueprint, grind one face of a glass disc to a spherical curve of about 13 cm radius, working down through the grits, then polish it clear with cerium oxide on a pitch lap. Leave the other face flat.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àwo dígí1 ẹyọ
Ọkà kaboidi silikoni200 g
Ohun ìdán ti cerium oxide50 g
Lẹ́ẹ̀ Oda Páínì100 gÀwọn irinṣẹ́ tí a nílò:
Ìdíwọ̀n2
2
Check the focus
Check the focus
Hold the lens in sunlight and move a card behind it until the spot is smallest; the distance from lens to card is the focal length and should be close to 25 cm. Do not look at the Sun through it.
Àwọn irinṣẹ́ tí a nílò:
Ìdíwọ̀n3
3
Turn the frame
Turn the frame
Turn a ring from a hardwood blank with a groove on the inside just wider than the lens edge, and part it off.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Igi maple fún àwo yíyí1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Ẹ̀rọ ìyí igi
Ìṣẹ́gún Onígun
Ọ̀bẹ ìgékúrò lórí ẹ̀rọ ìyí4
4
Turn the handle
Turn the handle
Turn a handle from a hardwood dowel and fix it into a hole drilled in the ring.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àwọn dowel igi líle1 ẹyọ
Ẹpọ́ksì Ẹ̀yà Méjì5 mlÀwọn irinṣẹ́ tí a nílò:
Ẹ̀rọ ìyí igi5
5
Set the lens
Set the lens
Saw the ring through at the handle, spring the lens into the groove, glue the cut closed and wax the wood.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Ìdí Oyin10 gÀwọn ohun-èlò
8- 1 ẹyọÀyè
- 200 gÀyè
- Àyè
- 100 gÀyè
- Àyè
- 1 ẹyọÀyè
- Àyè
- 10 gÀyè
Ìtọ́nisọ́nà yìí ń ṣe
Blueprint tó jọra
Àwọn blueprint wọ̀nyí pín ìmọ̀ — ọ̀nà, ohun-èlò tàbí ìlànà
CC0 Àgbègbè Gbogbogbò
Blueprint yìí ti jáde lábẹ́ CC0. O lè ṣe àdàkọ, yí padà, pín, àti lò láìsí ìyọ̀ǹda.
Ṣàtìlẹ́yìn Olùṣẹ́dá nípa rírà àwọn ọjà nipasẹ̀ Blueprint wọn Ẹ̀san Olùṣẹ́dá tí àwọn Olùtajà gbé kalẹ̀, tàbí ṣẹ̀dá àtúnṣe tuntun ti Blueprint yìí kí o sì fi sínú Blueprint rẹ gẹ́gẹ́ bí ìsopọ̀ láti pín owó-wíwọlé.