Tolerances
Why a ±2 µm cavity does not make a ±2 µm part, what a parting line and a slide add to the stack, and how DIN 16901 maps to DIN 16742.
DesignMost of it is decided
Most of it is decided
before the steel is cut.
Notes on the decisions a press cannot undo. Each one says what the process can genuinely do first, and where that stops.
Guides
Sink marks
What packing and mold temperature can close, where each of those stops working, and why cooling faster turns a visible sink into an invisible void.
CadQuery
Molded parts written in Python: draft, walls and ribs as parameters, and a fourteen-line check that catches the rib you forgot to draft.
Weld lines
A fill prediction splitting around an off-centre hole and rejoining 10 mm off the centreline — nowhere near behind the hole — and the levers that move that meeting point.
To put numbers on any of it, The Lab has the calculators — or the Comparator, which asks whether the tolerance you need is one anybody can hold.