Tag Archives: PCB

Bunnie’s Factory Tour Part 1: How To Make A BOM

Bunnie Huang posted an extensive explanation of how you’re doing your Bill Of Materials (BOM) all wrong. Here’s a taste. For the whole 5-course meal head over to his blog.

Most Makers trying to scale up quickly realize the only practical path forward is to outsource production.

Every single assumption, down to the color of the soldermask, has to be spelled out unambiguously for a third party to faithfully reproduce a design. Missing or incomplete documentation is the lead cause of production delays, defects, and cost overruns.

Here’s some of the things missing from the [typical] BOM:

  • Approved manufacturer for each component
  • Tolerance, material composition, and voltage spec for passive components
  • Package type information for all parts
  • Extended part numbers specific to each manufacturer

A complete BOM for an LED flasher also needs to include the PCB, battery, plastic case pieces, lens, screws, any labeling (for example, a serial number), a manual, and packaging (plastic bag plus cardboard box, for example). There may also need to be a master carton as a single boxed LED flasher is too small to ship on its own.

 

Tagged , , , , , , , , , , , , , , ,

Solder Free 3D Printed Circuit Board

3D printing is moderately useful. It will become much more useful when it can produce more than structural parts.

Automatically placing and connecting electrical components is still a ways off, although lots of people are working on it. Until then, CarryTheWhat has demonstrated an impressive DIY method of producing circuit boards on a 3D printer.

The key to how this approach works is a series of pegs connected by conductive thread. By strategically wrapping the conductive thread onto a peg board generated in OpenSCAD, the components of the circuit can all work together.

It’s a bit bulky and crude, but it works. For example, here is a flashlight…

If you’d like to see a step-by-step description of the process, CarryTheWhat wrote it up on Instructables and on Thingiverse.

Tagged , , , , , , , , , , , , ,
Follow

Get every new post delivered to your Inbox.

Join 55 other followers