|To build a wheel robot, use the
mechancial parts and materials from the obsolete and scrap PC
computer peripherals and
There are many useful parts in a PC computer equipment, such as
drives, hard drives, printers, and etc. These mechanical
parts can be used for projects and experiments. Most of the components
are removed from the equipment that still function. Many of the
parts will not fit well
completely in the project, but most of them can be easily modified.
In this project, to build a 3-wheel robot, the
parts and materials are collected for suitable dimensions and shapes so
that they can be modified according to the project design. I have
salvaged a lot of parts from computer equipment to build a
|Part 1 -
Mechancial parts and assembly
driving wheels and axial
|First, start with the driving
wheels. Two spindle pulleys are removed from
two 5.25" Shugart floppy
drives, and two spindle hubs with bearings are taken from another 5.25" floppy
drives. A paper roller shaft is removed from an HP LaserJet printer.
spindle pulleys will be used as driving wheels for the robot.
They need to be modified by boring a larger hole at the
center so the
bearing hub can fit into it. The rim face is cut with a V-grove
0.125" deep for holding an o-ring as a tire.
Cut a piece of a suitable
the paper roller shaft for the wheel
The diameter on both ends should be turned to a smaller size using the
lathe, so the bearings can be mounted onto it. The center section
is milled flat at about 0.05"
depth and tapped with two #6-32 threaded hole for mounting onto the
is the Seagate ST31276A hard drive housing. The hard drive
is made of cast aluminum and with a thick support. The robot base will use
this hard drive mounting plate.
seagate hard disk housing plate is finished with the surface cleaned
a milling machine, and drilled the necessary holes for mounting all the
parts and assembly
||The parts and
materials needed for making the caster wheel are: a leftover laser
printer paper roller shaft, which part of it is used for the wheel axial, two pieces of
laser printer hardware, a
5.25" floppy drive spindle hardware, a floppy drive spindle flange
bearing, a CD-ROM drive
laser head sliding pin with 2 brass brushings, and a mouse ball.
The mouse ball is drilled with a hole through the center, the two
are counter bored with the diameter equalling to the size of the
brass brushing with about 0.1" depth (about the same length of
the brass brushing). The drill through center
slightly larger than the diameter of the sliding pin.
The shaft and the bearing are used for making the swivel joint
of the caster wheel.
|| Drilling a center hole on a
round steel ball will be quite difficut, so I
find it easier to drill it on the lathe.
This is the
complete set of modified parts for the assembly of the caster wheel.
This is the
caster wheel assembly. The CD-ROM laser head sliding pin and the two
brushings are inserted into the drill hole on the center of the mouse
ball as a wheel axial.
|Two stepper motors were removed
from two 5.25"
floppy drives. The specification for the motor is a 12V,
per step unipolar drive. The motor shaft comes with a
pulley attached to it that needs to be modified for mounting the smaller plastic
Test all the
wheels so they can move smoothly.
Next step is the installation of a controller for test drive.