Vertical Placement of Vibroplex Style Speed Keys

I've been using speed keys since 1958 but I've never experimented with trying to place them vertically until recently.   The articulated damper assembly of Vibroplex Original keys are designed to be used horizontally.   So it requires a slight modification for vertical operation. Which takes only a few minutes as below: 

1.  Lock the articulated damper arm in place by wrapping string or fishing line around the bottom of the damper assembly and around the articulated arm so that the articulated arm is held firmly in place.
2.  Lock the damper ring in place by securing it with its screw.
3.  Place a rubber O ring of the proper size around the damper wheel or replace the metal damper wheel with a rubber wheel of the same size.  Hardware stores have rubber wheels of the type used in faucet repair and you should be able to find the correct diameter needed.
See the below picture of the easily modified damper with the rubber O ring.

Now, all the dampening of the dot arm will take pl…