EMBRACING
CHAOs.
DESIGNING NAOS

Push-to-Grip Mechanism A push-driven clamp for the mop head

A 16 mm push closes the clamp through 30 mm of jaw travel. A helical cam turns a 16-tooth involute pinion, the pinion drives two opposed racks, and a ratchet holds the grip. The 16 parts are Grasshopper C# components that share one base plane, so the stack builds coaxial and every number in the spec is checked against the others.

Jaw travel

30mm

Grip

79N

Push stroke

16mm

Height

44mm

1. The push sets the budget. Rack force × travel = push force × stroke, 2400 N·mm either way, so doubling the travel from 15 to 30 mm halved the grip from 158 to 79 N. No cam geometry avoids that; a two-stage cam spends it unevenly instead, with 158 N over the last 6 mm.
2. The wrap-spring clutch failed on the bench. Its steel coils cut a thread into the printed shaft and turned freely both ways: line contact puts PLA, PETG and POM at 2–3× their yield. The build moved to a ratchet and pawl, which loads a tooth flank in compression.
3. Sized for the worst case. 169 N at the pawl gives 22.4 MPa of face pressure and 33.2 MPa of web bending, against about 65 MPa for POM.

Screws, Nuts & Springs For printed and machined parts

Paste-in components that build a screw and the hole it passes through, the tapped thread or captive nut it bites into, and compression springs with the load they will take. One plane goes into both sides, so the screw lands in its own hole with the head bearing on the face.

Thread sizes

63

Material presets

13

Vs. Shigley 10–1

0.4%

1. Two paths, two sets of settings. A steel screw from the drawer needs a clearance hole and something to bite into, not a printed thread. The 13 presets start from how the part is made: machined, tapped after printing, resin, PLA, PETG, nylon and more.
2. Springs checked against the book. Rate, safe load and stress at solid follow Shigley, chapter 10, and match its Example 10–1 to within 0.4% in metric and inch documents.
3. No printed springs, on purpose. A spring works in torsion, the weakest direction of an FDM part, so the notes say to print one and measure it.

Quad Mesh from Curve Chains Retopology, quads only

Turns a network of edge curves into a mesh made only of quads—no triangles, no pentagons. It merges endpoints that nearly meet, builds every four-sided face it can, and returns the boundary faces it could not close as polylines, together with the naked and interior vertices, so a gap in the network is easy to find.

Version

27

Sides per face

4

Outputs

6