The grass growing along the walkways framing the back lawn is getting kind of long.

There's an edger attachment that we could use with GrandDad's lawnmower, but it's one of those ones that uses a plastic cord to cut the plants, and it can't really stand up to the tough St. Augustine grass that marks this yard.

There's a bulky old metal edger with a gasoline engine that my mother remembers from when she was a little girl. It's got a nice sturdy blade, but the engine doesn't start properly. GrandDad told me what he thinks is wrong with it, but I didn't really understand.

My ideas for solving this situation: (1) Hire someone to come trim the edges of the lawn -- someone who will bring his own edger. Barring that, (2) Buy a whole new edger. I remind GrandDad that he has a gift card to Sears burning a hole in his pocket, and I'd be happy to drive him there whenever he'd like to go.

GrandDad's idea for solving this situation: Remove the gasoline engine from the ancient metal edger and replace it with an electric motor.

He has several electric motors lying around. Because he saves motors. Because you never know when they might come in handy some day. The one he selected as the most suitable match came from a refrigerator.

Turns out, swapping out a gas engine for an electric motor that you just happened to have lying around is a fairly involved process. Since the new motor was in no way engineered to fit the new application, there are several little adjustments that must be made for it to work in its new home. So it's an intellectual puzzle to figure out how to this, with the least unnecessary work, using tools and supplies on hand as far as possible.

I've been sought out for my skills as a lifter of moderately heavy objects onto the workbench at several points in the process. At dinner each evening, I get the update on the day's progress. I listen carefully and nod intently, but I only have a very general idea of what he's talking about. Suffice to say that I wouldn't have clue one how to replace an engine on a small household appliance.

But it's an interesting challenge for an electrical engineer. He consulted some of his college textbooks (from the late 1930s) to get back up to speed on some of the details of wiring small motors. He experimented with a fix that didn't work, then figured out why it didn't work, then came up with an alternative solution to the problem.

This morning he asked me about the provenance of a metal tube he had found, to make sure it was okay to cannibalize it for a part he needed to attach the new old motor to the edger. I told him to help himself: It used to be the handle of cheap household dustmop that I had purchased a year or two ago, which broke on practically my first attempt at using it. After a failed attempt at repair with superglue and duct tape, I had thrown the whole thing in the trash bin, whence GrandDad had salvaged the handle, because, presumably, it might come in handy someday.

Today he finished the wiring job on the new old motor. He used a power cord from an old microwave.

This afternoon I started listening to the audio edition of Shop Class as Soul Craft by Matthew Crawford. I downloaded the WMA files from my public library website over a security-enabled home wireless network, the workings of which are even more a mystery to me than those of an internal combustion engine. Crawford makes an extended case for the intellectual satisfaction of skilled manual work and the psychological value of being the master of one's own stuff, but I don't need a book to tell me that. I just need to look down the hallway to the workshop in our garage.