Timing Belt Drive Sizing: Belt Width, Tension and Tooth Load
Design Review: GT2 Timing Belt on a Linear Axis This is the review notes from a linear axis that started slipping under load. The belt was GT2, 6 mm wide, on a 20 tooth pulley,…
Author: JUMI
Machine Cycle Time Calculation: Moves, Ramps and Bottlenecks
The Machine That Missed the Cycle Time by 3 Seconds We designed a machine for a customer. The required cycle time was 12 seconds per part. On paper (in the design calculation), we summed the…
Sensor Bracket Design: Rigidity, Adjustability and Anti-Drift
Sensor Bracket Design: The Quick Reference A photoelectric sensor on a 1 mm bent sheet-metal bracket. The bracket flexed under the vibration of a nearby press. The sensor drifted 2 mm in three months. The…
Robot Gripper Force Control: Holding Without Crushing
Five Things Everyone Gets Wrong About Gripper Force We crushed a batch of 500 plastic housings before anyone asked the right question. The pneumatic parallel gripper was spec’d at 400 N force. The parts were…
Welded Frame Design and Machining: Distortion, Pads and Tolerance
A 6-Meter Conveyor Frame: From Drawings to Machined Pads This is the story of a welded conveyor frame — what we drew, what the shop welded, what warped, and what we changed for the next…
Limit Switch Actuation: Over-Travel, Inductive Derating and Rigid Mount
The Proximity Switch That Never Triggered We used an inductive proximity switch to detect a metal part arriving at a station. The switch was rated for 2 mm sensing distance. On the bench, it detected…
Pneumatic Tubing Bend Radius and Routing: Static vs Dynamic
Static Tube vs Dynamic Tube: The Radius Decision Nobody Makes on Purpose A polyurethane tube running to a moving cylinder cracked after 30 days. The bend radius at the fitting was 15 mm — tight…
Spring Selection for Detents and Plungers: Holding Force and Notch Geometry
The Detent Ball That Wouldn’t Hold We used a spring-loaded detent ball (a ball in a tapped hole, pushed by a spring) to hold a rotary handle in position. The spring was a standard compression…
Shaft and Keyway Design: Shear Stress, Crushing and Splines
Keyway Shear: Answered by the Shop Floor A 25 mm steel shaft driving a conveyor pulley. Standard 8×7 mm square key. One week into production, the key sheared clean across. Torque was only 30 N·m…
Gearbox Efficiency and Heat: Planetary vs Worm, Continuous Duty
Gearbox Heat: The Number You Forgot to Calculate Every gearbox absorbs a slice of input power as heat. The slice depends on type, stage count, and quality grade. If you size the motor for the…
Ball Screw Preload and Backlash: C7 vs C5, Double-Nut and Heat
Post-Mortem: The Axis That Lost Its Edge What happened. A high-speed pick-and-place axis on an assembly cell started showing positioning drift after eleven months. The integrator had run the axis at 1200 mm/s with a…
Non-Standard Automation Equipment Design: From Spec to Handover
Non-Standard Automation Equipment Design: From Spec to Handover The non-standard automation equipment is the machine that is designed for one customer, one part, and one process. The standard catalog does not cover it, the handbook…
Sheet Metal Design for Enclosures and Machine Guards
Sheet Metal Design for Enclosures and Machine Guards The sheet metal part starts as a flat sheet and becomes a box, a bracket, or a guard through the bending and the cutting. The sheet metal…
FEA for Machine Frames: Where the Stress Really Goes
FEA for Machine Frames: Where the Stress Really Goes The machine frame looks solid and fails anyway. The weld cracks at the corner, the gusset tears at the bolt, and the table sags under the…
Designing for CNC Machining: Rules That Save Money
Designing for CNC Machining: Rules That Save Money The part that is designed for the machine is the part that is cheap to make. The part that ignores the machine is the part that fights…
