CR20KBTools for real problems
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CR20KB · TOOLS

Useful tools, no registration.

Browser generators and calculators built around real engineering and everyday problems. Public tools stay free.

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LIVE

Fastener

Print-tested STL generator for bolts, nuts, studs and washers with thread and FDM clearance settings.

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LiFePO₄

Runtime, remaining charge, recharge time and battery sizing for power outages and real loads.

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Fuel Range

Full-tank range, fuel needed, trip cost and fuel stops. Metric for RU and US gallons/MPG/miles for the US.

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Poisson

Probability of exactly k events in a cell or time interval, plus the expected number of matching cells.

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TEST

Plate Keychain

Custom license-plate keychain generator with local STL export. Working TEST version; further polish depends on real usage.

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TEST

CrossText

Experimental crossed-text STL generator. Known geometry issues; active development is paused.

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LIVE

Optical Transfer

Screen-to-camera file transfer with animated QR codes. No network path between devices.

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POISSON EVENT CALCULATOR

Сколько событий попадёт в ячейку?

Задайте общее число событий и количество одинаковых ячеек или сразу введите среднее λ.

Например, спички, дефекты, заявки.
Сетка 5×5 = 25 ячеек.
k = 0, 1, 2, 3…
λ2.20
P(X = k)26.81%
Ожидаемо ячеек6.70
P(X=2) = e^-2.2 × 2.2² / 2! = 0.26814
kВероятностьОжидаемо ячеекP(X ≥ k)
Модель подходит, когда события примерно независимы и средняя интенсивность на одинаковых участках площади, времени или объёма примерно постоянна.
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