finish off the lathe work on the
piece, I drilled a 3/8” hole through
the center for the bushing, then
used the parting tool to cut it off
from the stock (Figure 14).
Next, I simply pressed in the
bushing using the vise on my drill
press; this created a nice tight fit
that with any luck will never come
out (Figure 15). I was down to the
last stages of this piece and the
robot, so I grabbed my disc, set it up
on the piece, marked it out, and
began drilling three 13/64” holes
which I later tapped out to 1/4-20
(Figure 16). The disc had room for
six 1/4-20 bolts but three is more
than enough for an antweight.
MANUFACTURING:
Comp sites – Part 2
● by Bradley Hansted
In this month’s article, I will cover a very basic lay-up process, the tools
you need, and the safety
precautions to take. I will be diving
right into the steps one may take to
make a simple two ply carbon fiber
panel. I highly recommend reading
my first article from Sept. if you are
new to composite structures as you
will learn information that will carry
over into these steps. Some terms
and abbreviations will be used in this
article that you may not know. To
decipher these terms and learn
where to ask more questions, head
over to: www.teamthinktank.net/
composites.
Before going to cut up a bunch
of carbon fiber to make a panel, you
first need a surface in which to cure
your part. Planning ahead is key to
fabrication as you may be in gloves
with resin on them and forget to get
something out. Always walk through
the process in your head to make
sure every step is covered. So,
before you cut up your cloth and get
out the resin, choose what shape
and what surface this part will be
made on. For this simple flat panel,
we will use a flat 1/4” thick
aluminum plate that at least has 2”
of extra material on every side to
PHOTO 1. TTT’s aluminum mold plate with
two heating bands and hose connection
barb for easy vacuum bagging.
whatever sized composite part you
wish to make. Aluminum is great
because you can transfer heat to the
part which will aid in curing and it
can be polished easily for a great
looking part. Whatever the surface
of the mold plate looks like is exactly
what you will get in your finished
part. So, sand or prep that plate to
your desired finish.
Now that we have a mold, it’s
time to get your cloth ready. Cut the
bi-directional carbon fiber cloth to
slightly larger than the desired size
plate you wish to make. The reason
to have excess on the ends is
because it is almost impossible to
ensure the ends of the fabric are
perfectly aligned and not frayed by
the time they are impregnated with
resin and cured. No matter what
part you make you will always have
a small lip around the part to cut off
later. Cutting the carbon fiber can
be a bit tricky, but it is nowhere near
as hard to cut as kevlar, so just get
out some strong fabric shears and
get those pieces cut to size.
SERVO 10.2010 29
