Friday, January 11, 2013

The Robot Dragster Project - Chapter Four

When doing a student project one question arises that you might not anticipate.

How much engineering is the right amount?

The Robot Dragsters are supposed to work, or at least have enough prospects of working that we can have fun testing them.  But they do not have to work for very long, or perfectly, or better than any competitive products being sold in the marketplace.  So it would be silly to build out of expensive materials, or to have some aspects of the project be created to microscopic tolerances while other elements are plywood and lag bolts.

Of course with kids, their default mode is to suggest we just use duct tape and hot glue. And when pressed for specifics as to just how things can be made to fit together, they resort to hazy concepts expressed primarily with vague gestures.  In other words they resort to "handwavium".

We covered this topic on our last build session before the Christmas break.  I introduced them to the concept of "good enough" engineering.  If a simple, cheap, inelegant solution will work for long enough to satisfy the need at hand, do it.  This is often referred to as "Kludge" or as "Ghetto Engineering".  The latter term is a little out of favor, but I am not sure why.  If ghetto references the original meaning of a community where Jewish folks reside, and you look at the percentage of Nobel prizes won by said Jewish folks, it is a high standard to attain indeed.

But I actually prefer the term "Bigger Hammer Engineering".


Rather an off session for working on Thursday.  The kids were rusty after the Christmas vacation and my usual assistant was not able to be there.  In place I had my Number 2 son help out.  He is a machinist/welder/tinkerer of phenomenal abilities, so working with plywood and squirrels was probably hard on him.  But I told the kids that after this they could in later years say that they had once worked alongside a genuine Master.

There are a couple of kids who really love hammers.  We have no difficulty finding things for the "Hammer kids" to help tap into place.

Pulley in place and held in with key.  Improvised bearing blocks from old, cut up ping pong table.  Just before we ran out of work time we were able to put the belts on and fire it up. With a 1:1 ratio the MagMotor makes the axle scream.

Angle grinders are noisy.  Who would have thought middle school kids were that sound sensitive...the entire school is a maelstrom of racket all day long!  Although I have not been all that emphatic on hearing protection-the loud tools are just in use for a few seconds at a time-we are immaculate regards eye protection.

I keep the budget minuscule by using the items in hand.  This will be a hub for the "light" dragster.  It was once a chain sprocket for a 60 pound combat robot.  Widening a few of the holes will not limit its future use for some purpose yet unknown.

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