I trust that many of us are old enough to remember who Rube Goldberg was. He was, among other things, an engineer and a cartoonist. He is best known for his humorous cartoons depicting complicated mechanisms to perform simple tasks. His designs were fictitious, but I’ve encountered some real-life examples that have gotten into production and perplex me to this day. I’d like to start a museum of these and more examples of stupid engineering in honor of Rube. Some ideas are stupider than others. I know of any units of stupidity so I will propose the “duh.” I think Homer Simpson may already have a copyright on “D’oh.” Kind of stupid rates one duh, really stupid gets two, and incredibly stupid gets three.
One exhibit in my virtual museum is the Briggs & Stratton engine in my now discarded lawn mower. For the convenience of the user, it has an electric starter, just like every modern automobile. It takes some effort to overcome the compression of an engine to start it. The obvious approach would be to use a starter motor large enough to do this. A less obvious choice would be to provide some mechanism to relieve some of the compression while cranking.
In my chainsaw there is a simple push-button poppet valve that closes itself when the engine fires. Briggs & Stratton came up with a way more complicated mechanism to do this. It consists of some sort of a centrifugal weight device on the camshaft that holds the exhaust valve open until the rotation rate is high enough that the weights pull a sliding collar on the camshaft allowing the valves to operate normally. Those extra moving parts eventually move too far as the weights fly off and end up in the crankcase rendering the engine inoperable. When I took mine in for repair, the guy was able to easily show me the problem because he had three more that he was working on with the same problem. He allowed as how it was a pretty stupid design. Probably that gets two duhs.
Another exhibit is what I encountered with my Model A Ford valves. With most cars of that vintage, a valve job is something commonly required and simple. With the cylinder head off, remove the valve keepers, pull the valves out, grind the valves, and lap the seats. Then reinstall the valves and turn the adjuster nuts on the lifters to reset the gap to compensate for the material lost in grinding and lapping.
On the Ford, it’s not quite that simple. The valves can’t be simply pulled out because they have a mushroom shape at the bottom of the stem. A special tool is required to remove the valve guides before the valve can be removed. Once the grinding and lapping are done, adjusting the valve gaps requires a trial-and-error procedure of filing to shorten the valve stems since the lifters are not adjustable. If a valve stem ends up too short due to over-filing, replace it with a new one and start over. This procedure turns what could otherwise be a four-hour job into a one-week job. It’s hard to imagine that a group of competent engineers sat around a table and agreed, “Yeah! That’s a good idea. Let’s run with it.” I think I’d assign that entire kludge two duhs twice.
Well, those are my submissions to “The Rube Goldberg Memorial Museum of Stupid Engineering.” There will certainly be more. I’ll bet you have some too. I’ll be waiting to hear from you.
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