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From software algorithms to material selection, Mr. Roboto strives to meet you
where you are — and what more would you expect from a complex service droid?
I didn’t have a lot of questions this month, but what I
did get sure caused a bunch of research. I wish that I had
time to program up some examples, because they would
be very cool. So much to do, so little time! I hope that
everyone is busy building and programming bots and that
is why it has been so quiet.
Robotics is composed of so many areas of expertise,
mechanical, electronic/electrical, and programming that it
can be a formidable hurdle to just get started. But oh, the
satisfaction when you succeed!
My first question involves one of the highest hurdles to
Q. I am sure you have heard this a million times before. I'm new to robotics and I don't know how to attach wheels to my motors. Can you help me?
— Clueless Mover
A. Yes, I have heard this one before. I have solved this problem in a number of ways over the years, starting with DIY methods that sometimes even worked. My
DIY efforts got more sophisticated when I gained access to
folks with lathes and mills. My first efforts were matching
motors that I found or got from surplus vendors to wheels
that I had from RC car racing or — my favorite — LEGO
Technic kits. Figure 1 shows my DIY efforts. Sometimes you
can just "fake it".
Figure 2 shows me using a REALLY big servo disk. It
worked, and if I found some small rubber bands would
even get traction! The robotics hobby industry has gotten
into the act and creates kits and motor sets now that work
for basic needs. Figure 3 shows a hub set from Jameco
( www.jameco.com) that matched some of my commonly
found surplus motors. I just had to carefully drill out wheels
to use the bolt patterns. The Mark III kit ( www.junun.org/
MarkIII/Store.jsp) created specially molded
wheels to match hobby servo shafts for their
robot kit (Figure 4). I really like this chassis. It
is simple and very usable in lots of robot
tasks, including its original purpose — robot
Other companies also made custom
wheels that used servo hubs attached to
them; the one I show in Figure 4 came
from Budget Robotics (www.budget
robotics.com). Solarbotics (www.
solarbotics.com) has DC gear motor sets
that they matched their own molded wheels
to (Figure 5). These motors did not mount
easily to established bases, but by using
double-sided sticky tape (also called servo
tape in the RC hobby), they attach well just
You can get pretty creative with the
solutions that I've mentioned so far, but
nothing beats a motor/hub/wheel
combination that is meant to go together.
Figure 1. DIY efforts. The one on the far right adapts a shaft to LEGO wheels.
14 SERVO 08.2011