How do I free a router stuck in its base?

I use a Porter-Cable router 90 percent of the time with a fixed base in a table and 10 percent with the handheld plunge base. Recently, I was plunge-routing ³⁄₄ " MDF. After finishing the job, I could no longer remove the router from its plunge base. I assume it's clogged with fine MDF powder. What should I do to get the router free?
—Darrell Phillips, Mt. Desert, Maine

If fine dust has packed the spiral grooves in the base, that could be your problem, Darrell. Start by trying to remove as much dust as possible using compressed air. An aerosol penetrating oil or WD-40 also may loosen up the jam, although you'll later have to remove all lubricant from the motor housing and base to avoid attracting more contaminants.

The experts at Porter-Cable offered another possible explanation for this jam. Transferring the motor between bases may have produced an accidental nick on the motor housing, raising a burr that keeps the housing from turning inside the base. If you spot a small nick or raised sliver of metal, carefully remove it with a fine mill file or piece of sandpaper.

While you're at it, check for other possible contaminants that may cause the housing to stick in its base. These include errant dabs of glue on the motor housing or wood chips in the grooves.