Black and Decker? I thought they just made disposables. If the blade
is dull throw outthe saw and buy one with a fresh blade. ;^)

Actually, if it is slipping when you hold the balde then it isn't so
tight it shouldn't be able to break it loose. If there is no obvious
brake, which I assume there isn't I can think of two options.

1. See if there is any cooling opening in the moter wherby you can
gently JAM in a screwdriver or other implement to hold the motor while
you work the nut.

2. If you have a hammer\impact drill and can set it up with a socket,
that will surely breal it loose, as long as it is spinning the right
direction. Nothing works better than vibration. Along that same line,
holdingthe blade and doing some light tapping on an open end or box
wrench can have the same effect.

Also might try some wd40 or other penetrating rust\sieze killer but of
it gets between the blade and washer it will more easily slip so be
careful.

On Nov 10, 9:28*am, Tom wrote:
Black & Decker miter sale model 7715 type 3.

I bought this saw at a garage sale. the seller cut a board, said it
needs a blade. But, I can't remove the old blade. The armature of the
motor turns when I try to turn the *blade nut. If I "jam" the blade so
it can't turn, the armature still turns. How do I lock the motor to
remove the blade?