Porter Cable plunge router motor lock
After the failure of my second Craftsman router a couple of years ago, I picked up a used Porter Cable 690. Several times I've needed a plunge base so I recently picked up a 6931 base in need of repair for a good price. A new plunge clamp knob, depth gauge rod and depth pointer come to about $7 plus shipping, using a 3/8" rod from my miscellany box.
The other problem is the motor lock allen bolt and associated hardware are missing. Replacements are about $10, mainly due to the specially machined clamp and nut. After studying the parts diagram and the user's manual, I get the impression this is a pretty mickey mouse way of securing the motor to the base. The clamp, nut and bolt have to be removed with a hammer tap to remove the motor, making them subject to wear, loss and pricey replacement.
Given the motor's tight fit in the base, I think a chunk of rubber compressed by an allen bolt and a small plate on the bottom should be enough to lock the motor in place. I can't see the thin metal clamp providing significantly more force. The rubber should retract enough when loosened to allow motor removal without dismantling the clamp assembly.
I'm wondering what experiences others have had with this lock mechanism. Is it as troublesome as I suspect it to be and if so has anyone found an alternative? Is my plan viable or should I bite the bullet and spend the $10 upfront and maybe another $10 in the future?