Robot builders often find that the trickiest part of a robotics project is
making the wheels. First you need to find a suitable tire/wheel combination,
then you must figure out a way to attach a sprocket so that it will handle
the torque of a geared-down drive motor. Our wheel/sprocket/bearing
combination will solve those problems for you!
We
start with the Colson Performa wheel. This line of wheels is very popular with robot
builders. The combination of high-traction rubber and light weight make it ideal for
combat robots. The wheels are 4, 5, or 6 inches in diameter and 1.5 inches wide. We reduce the width
of the hub and broach a 1/4" keyway into the hub.
Our custom one-piece hub/sprocket also gets a 1/4" keyway machined into
the hub. A steel key locks the wheel and sprocket together so the torque on the sprocket
gets transferred to the rubber tire. The hub/sprocket is made from
chrome-moly steel.
A bronze bearing is
pressed into the sprocket, then the sprocket/bearing assembly gets
pressed into the Colson wheel. Our 19-tooth sprocket is made to be used
with #35 roller chain.
We planned to use a bronze bearing on the opposite side of the assembly but we
get such a good volume discount on these ball bearings that we decided to use the ball
bearings instead. Both bearings have an inside diameter of 1/2".
This
section view shows all five components in the final assembly. The inner
race of the ball bearing extends into, (but does not touch), the inside
diameter of the hub. The width of
the assembly is 2.24" which fits perfectly into our 2.25" wide
modular drive units and
robot kits. Use washers or shaft collars to locate your
wheel on your axle if the axle is wider than 2.3", (this also keeps the bearings from
working their way out of the wheel).
This combination of components weighs in at just 1.1 pounds - or
4.4
pounds for 4 wheels. We believe that this is the lowest-cost and lightest wheel/sprocket
combination available.
This
wheel is very easy to use because the axles in you robot can be
non-rotating and fixed in place. That saves you the time and cost of
mounting your axles in bearings. The picture on the left shows the wheel
mounted in our modular drive unit.
The 4" inch wheel is the standard wheel that is used in all our
kits. Also available are our 5" and 6" wheels. The 5" wheel can be
used to increase ground clearance in our kits but its use will
require modifications to the frame and a new drive chain. All wheels come with our standard 19-tooth sprocket.
We
start with the Colson Performa wheel. This line of wheels is very popular with robot
builders. The combination of high-traction rubber and light weight make it ideal for
combat robots. The wheels are 4, 5, or 6 inches in diameter and 1.5 inches wide. We reduce the width
of the hub and broach a 1/4" keyway into the hub.
Our custom one-piece hub/sprocket also gets a 1/4" keyway machined into
the hub. A steel key locks the wheel and sprocket together so the torque on the sprocket
gets transferred to the rubber tire. The hub/sprocket is made from
chrome-moly steel.
A bronze bearing is
pressed into the sprocket, then the sprocket/bearing assembly gets
pressed into the Colson wheel. Our 19-tooth sprocket is made to be used
with #35 roller chain.
We planned to use a bronze bearing on the opposite side of the assembly but we
get such a good volume discount on these ball bearings that we decided to use the ball
bearings instead. Both bearings have an inside diameter of 1/2".
This
section view shows all five components in the final assembly. The inner
race of the ball bearing extends into, (but does not touch), the inside
diameter of the hub. The width of
the assembly is 2.24" which fits perfectly into our 2.25" wide
This
wheel is very easy to use because the axles in you robot can be
non-rotating and fixed in place. That saves you the time and cost of
mounting your axles in bearings. The picture on the left shows the wheel
mounted in our