Pololu

Pololu makes the role of a component a useful starting point. Its comparison routes separate motors, robot kits, regulators and controller types, rather than presenting every board as a general project accessory. For a robot kit, the store also distinguishes beginner and more advanced options and whether soldering is involved. Use those differences to define the shortlist before comparing a particular part. The useful output is a documented set of candidate components; selecting a motor or controller still requires the corresponding technical specifications and the requirements of the planned system.

Pololu lets an order with backorders ship in two stages or wait until every part is available. PayPal is charged for the full order at checkout; credit-card charging follows the shipments, with pre-authorisation for an order held complete. Shipping options appear after the address and before payment details, which helps compare a project’s delivery cost before committing.