Page 107 - Robot Builder's Bonanza

76 WORKING WITH WOOD

2nd cut

Final cutout

1st cut
Figure 7-9 Rounded shapes may
be cut using a jigsaw, coping saw, or
scroll saw. This method requires a bit
of practice to get right.

1. Use a backsaw to make cuts 1, 2, and 3. A backsaw is preferred because it will make
straighter cuts.
2. Use a coping saw for the fourth and final cut.

And finally, there’s no reason why the wheel wells must have right- angle corners. Figure
7-9 shows the rounded contour of the wheel well when using a jigsaw (or a coping saw) to
make just two cuts. Go slow, and make a couple of trial cuts first on a piece of scrap. This
technique requires a bit of patience and a little skill for good results.

CUTTING A FRAME
Frame construction allows you to make larger but lighter robots. The frame provides the
overall skeletal structure of the bot, and over the frame you can place light materials to sup-
port the components of your machine. Frames also allow you to build tall robots in the same
way they construct multistory buildings. You can stack multiple frames on top of one another,
with the equivalent of pillars between them.
Wood frames can be constructed using strips of hardwood. Most hobby stores stock birch
and mahogany, both excellent choices. You can buy the strips premade or cut your own if you
have a table saw. For frames under 10″ square, strips 1/2″ to 3/4″ wide are adequate; use 1″
or wider wood for larger robots.
Wood selection for framing is critical. Stay away from softwoods, such as pine, fir, and
redwood. They are not strong enough except for the smallest of bases. Aircraft- grade hard-
wood plywood is also a good choice.
Frames are best made using a small miter box and a backsaw. You can purchase both of
these for under $20 total. It’s a small but wise investment. The miter box helps you make the
straight and angled cuts necessary for frame construction.

Accurate Measuring a Must
The miter box will help you to make proper 45° angle cuts, but you still have to be careful that
each of the four pieces of the frame is the exact proper length. Otherwise, the frame will not
be a perfect square— or a perfect rectangle, whatever the case may be.

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