Simple Double Bumper Construction Guide

This is a simplified version of the double bumper from the LEGO Constructopedia that comes with the Mindstorms kit. The aim is to replace specialized parts with simpler ones.

Step 1

Start by picking out:

one grey 2 x 10 plate;
two grey 2 x 6 plates (with holes);
two grey 2 x 2 plates; and
one black 2 x 2 block.

Sandwich these together:

and place a touch sensor on both ends:

Step 2

Take:

two grey cams;
two yellow angle beams;
two black friction connector pegs;
two black 3-stud axles

Slot a friction connector peg and an axle into the angle beam, and attach a cam to the axle:

Repeat.

Step 3

Now take:

one black 8-stud axle;
two cross-axles; and
two right-angle connectors.

as shown:

and assemble them as laid out:

Step 4

With:

one yellow elastic band;
two grey bushings; and
two short wires.

Combine all the assemblies from the previous steps:

Step 5

Complete, using:

two grey 2 x 6 plates (with holes)

Parts required

one grey 2 x 10 plate;
four grey 2 x 6 plates (with holes);
two grey 2 x 2 plates;
one black 2 x 2 block;
two grey cams;
two yellow angle beams;
two black friction connector pegs;
two black 3-stud axles;
one black 8-stud axle;
two cross-axles;
two right-angle connectors;
one yellow elastic band;
two grey bushings;
two touch sensors; and
two short wires.