42 SERVO 06.2016
Figure 1. Drill and cut the motor arms to match your hardware. These dimensions work for my motors and landing gear design.
Cutting and Drilling Tips
Working with raw materials is always tricky, and
there are a lot of “gotcha”moments when learning to
fabricate. I wanted to share a few tricks I use to cut and
drill materials to help you save time and reduce wasted
Always remember to take proper safety precautions.
Saving a few minutes isn’t worth a trip to the hospital
with a cut or drilled hand. When cutting a piece of stock
to length, it’s easy to mark, cut, and end up with
something too short. This is a common error that comes
from not accounting for saw “kerf.”
This is the lost material that the saw removes when
making a cut. It’s generally slightly wider than the blade
of the saw (or exactly the width of the laser beam if
you’re lucky enough to have a laser cutter).
I mark my materials exactly the length I want and
then make a tick mark on the “outside”of what I want to
use, i.e., the stock material (Figure S1). When I cut the
material, I cut with the saw on the side of the line with
the tick mark, and just take the line out with the edge of
A related mistake is marking multiple cuts that are in
series with one another. The kerf introduces error there as
well, so mark, tick, cut, repeat!
This project will involve drilling several “blind holes”
that do not go all the way through the work piece. There
are several ways to do this, but I used two of my favorite
methods that I want to share.
First, if you have a drill press, you can set a limit on
the spindle travel. I put the material I’m drilling
down, then with a square or ruler set the drill
depth by adjusting the depth stops (Figure S2).
If you’re not using a drill press, you can use
the tape method with a hand drill. Measure the
depth from the tip of the bit and wrap the bit with
masking tape (Figure S3). Just drill until the tape
is flush with the top of the stock.