Building Prototypes Dan Gelbart part 1 of 18 Introduction

Summary

Dan Gelbart introduces a practical course on building prototypes for students, scientists, and researchers without machining training. The course focuses on techniques and equipment that are quick to learn, especially water-jet cutting. It covers workshop setup, useful machine modifications, and step-by-step fabrication, starting with a simple enclosure. The methods can also support limited production.

The introduction shows how water-jet-cut sheet material, bending, and spot welding can be used to make a wide range of parts:

• Enclosures: Designs can include snap-on covers, knockouts, and keyhole slots. These features reduce assembly time and help prevent loose screws from falling into machinery. Gelbart favors building boxes from U-shaped pieces, which are easier to bend on a brake than parts that require frequent changes to the brake segments.
• Lightweight structures: Water-jet-cut dies can emboss ribs into sheet metal, adding stiffness while reducing weight.
• Flexures and hinges: Water-jet-cut and spot-welded flexures can replace slides or conventional hinges. They require no lubrication, have no backlash or wear, and can be made quickly. Examples include small fiber-optic positioners and nitinol cross-spring hinges, which offer a large elastic range.
• Springs: Springs can be cut from solid steel or made as spiral disc springs. Varying the spiral’s width allows designers to tailor the force-versus-displacement behavior, including progressive spring rates.
• Parts requiring precision machining: Water-jet cutting can produce most of a part, with only critical surfaces machined afterward. Gelbart describes painting a part before clamping and machining it, avoiding the need to mask those surfaces and clean them later.
• Complex assemblies: Mechanisms that appear complicated can often be built from simple bent and spot-welded sheet-metal sections, with thicker areas added where needed. Examples include a two-axis gearbox using timing belts and slip rings, and an adjustable chuck with a water-jet-cut scroll that uses an inserted steel ribbon instead of a fully machined, hardened, and ground component.

Content Type

This is an introductory guide to the course’s prototyping approach, tools, and example designs. No product reviews are presented.

Main Speaker

Dan Gelbart