You've got to be precise in this profession. If you trim off even
0.01 centimeters too much steel from a part you are machining, your whole
day could be wasted.
Today you've got a steel shaft set up on a lathe.
You want to trim the shaft down to 35.5 millimeters.
The original steel
is labeled 1.5". But you're not fooled by labels -- this piece of metal is
actually undersized by about .003".
Part A
First
you've got to figure out the actual size of the original piece of steel. All
the numbers you use should be rounded off to the nearest .001".
Part
B
OK, so you know the original size of the metal shaft
in inches, but you want to trim this piece down to 35.5 mm. That means a conversion.
You do some quick mental math to figure out how many inches this is. (1 inch
= 25.4 mm)
Part C
Whew. Now you're
getting somewhere. You know the original size of the shaft, and you know how
big you want the finished product to be. How much metal will you need to shave
off the original piece?
Part D
You
remember that on a lathe, the tool cuts off two times as much
metal as you calculate. To compensate for this, you need to set your tool
to remove 1/2 as much metal as you calculated. How much metal will you shave
off the shaft?
You cut the metal shaft. Did you cut off the right amount,
or are you going to have to spend the rest of the day redoing the job?
"The
only way a machinist is 'good' is with a good base in math," says James Grosmann.
Grosmann is the director of sales and marketing at the National Tooling and
Machining Association.
"There's a lot of trig and geometry that has
to be mastered. There are jobs some large corporations call machinists that
don't require as much math, but most of the industry call them 'button pushers,'
where somebody else programs the machine and the 'machinist' just pushes buttons
to start and stop the machine and measure the part. They are usually lower-end
jobs and are difficult to move up the ladder from. They can also be boring."
Ready to see the answers?