If you're early in the design cycle, resist the urge to jump straight to machined aluminum. Most fit and function questions can be answered with 3D-printed PLA or even laser-cut plywood. Save the expensive material runs for when the geometry is locked in.

For load-bearing tests, PETG and ABS hold up better than PLA and cost roughly the same to print. If you need metal properties early, look into cast urethane or filled resin — they bridge the gap between plastic protypes and full production parts at a fraction of the cost.

Local makerspaces are worth every dollar of membership. You get access to mills, lathes, and sheet metal brakes without buying or maintaining the equipment yourself. Many also have engineers in residence who can sanity-check your tolerances before you commit to a run.

When you do need machined parts, design for standard stock sizes and minimize the number of setups required. A part that machines in two setups instead of five can cut your quote in half. Keeping wall thicknesses consistent and avoiding deep, narrow pockets helps too. Small choices in CAD have an outsized effect on what a shop charges.

Prototyping Mechanical Parts Without Breaking the Budget