OPJAW

Articles

How Automated Fixture Generation Works

How OPJAW generates CNC workholding from STEP files. Surface analysis, strategy selection, pocket generation, and geometric validation.

Fixture Selection for Irregular Parts

How OPJAW scores fixture suitability for irregular parts using flat face ratio, compactness, and size fit — with case studies from real STEP files.

Clearance Fits for Workholding Pockets

Pocket clearance determines whether the part drops in by hand or moves under cutting forces. Decision table from 0.05 mm press fit to 0.25 mm free fit.

Internal Corner Radii and Tool Access

Every internal pocket corner must have a radius at least as large as the endmill. The relationship between tool diameter, corner radius, and when the pocket is too tight.

Pocket Depth-to-Width Ratio: When Shallow Pockets Fail

A pocket too deep cannot be machined with standard tooling. A pocket too shallow does not grip. The 4:1 limit and how to choose grip depth.

Tool Radius Compensation in Pocket Milling

The double-offset technique for tool radius compensation in CNC pocket milling. Exact clearance on walls, machinable corners, no hand-fitting.

Multi-Op Fixturing: Datum Transfer Between Operations

Machining a part in two operations requires the second fixture to register against features cut in the first. Datum transfer theory, flip geometry, and error accumulation.

Datum Reference Schemes for Fixture Design

How datum selection in GD&T constrains fixture design. Primary datum is the seating face, secondary is the clamp direction, tertiary is the stop.

Clamping Force and Part Deflection

How much clamping force is enough, how much is too much. Cutting force estimation, friction coefficients, and the crossover where the jaw deforms the part.

Thin-Wall Clamping: Deflection Limits and Jaw Design

When wall thickness drops below 2 mm, standard jaw clamping deforms the part. Deflection calculations, jaw contact area, and grip depth.

Tall Part Stability: Moment Arms and Clamping Depth

When part height exceeds twice the clamping width, cutting forces create moment arms that tip or shift the part. The physics of tall part fixturing.

Material-Specific Clamping: Aluminum, Steel, Titanium

Different materials require different clamping strategies. Yield strengths, recommended jaw contact pressures, and what happens when you clamp titanium like aluminum.

Minimum Wall Thickness in CNC Workholding

How thin can the wall between a pocket and a jaw edge be before it deflects under clamping force? The 3.0 mm soft jaw floor and the 1.0 mm manufacturing minimum.

Holding Round Parts: Collets vs V-Blocks vs Conformal Jaws

Round parts need different holding than prismatic parts. Collets, V-blocks, and conformal jaws each have concentricity and clamping trade-offs.

Zero-Point Clamping: Repeatability and When It Matters

Zero-point systems achieve 5-micron repeatability by decoupling the fixture from the table. When this precision matters, when it does not, and how to evaluate the spec.

Why We Built a Geometric Oracle

How OPJAW verifies generated workholding before you download it. Declared dimensional ranges, automated measurement, deviation flagging.