Picture of Lego Electric Connector
There are plenty of homebrew Lego sensors and motors floating around, but most use a bisected Lego electric cable or an increasingly sparse electric plates with wire soldered to the bottom.

I, on the other hand, wanted a connector that did not use a preexisting Lego electrical connector. I found a nice (discontinued?) female connector, for the longest time I thought female would be easy to make but then it hit me. Metal studs.

I did find a nice female at http://robotics.benedettelli.com/attachment.htm, but I wanted male For in Brick use

They are unbelievably simple and easy to make, and a large number of Lego electric bricks use male connectors.
I know with the NXT the RCX legacy connectors are all but obsolete, but I prefer them. They look more Lego and are on the RCX, Scout, Code Pilot, Cybermaster, Technic Control Center, Dacta Serial Computer Interface and the 9V train system.
(It is weird a Danish company fits SAE measure better than metric (4.85mm), but it does so I will use only SAE)
3/16 metal rod (I used zinc plated for a good appearance)
A brick that fits the connector or can contain electronics you wish to hook up.
I mainly used 2x4 stud megablocks due to the fact I do not wish to drill into my Legos

Step 1: Pick a Brick

Picture of Pick a Brick
  I used 2x4’s because that is all I really had and they work for most simple sensors and converters.

  The brick should have at least a 2x2 section of studs if you want a fully rotatable connection (can clip on at any 90 angle) but a 1x2 can be made to work (like the lamp brick).

  Of course a 2x2 flat would make a nice standard cable terminal.
mrmerino3 years ago
Aww, I'm glad you found a nice female. Although I guess you wanted a male, huh?
GoldCivetta6 months ago

good job using mega bloks instead of damaging LEGO!

You are using mega bloks instead of Legos. Just wanted to clear it up.
jazzzzzz (author)  Loganator123451 year ago
I know, I did not want to drill my Legos.