I volunteered to fix a bunch of older Vemco drafting machines (elbow type)
for the local high school. A frequent fault is that the graduated base
plate can no longer be clamped by the "Protractor Brake". Said brake is
simply a thin piece of aluminum with a shoulder that pinches (clamps) down
on the protractor. It is approximately the size of a nickel and about as
thick. I successfully filed 0.007 inches of one side, however, it is a
difficult task freehand and removes a lot of skin from the fingertips.
If it weren't aluminum, I would simply place it on my magnetic chuck.
One thought I had was to carve a recess into a block of wood and use that as
a work stop. An advancement would be to drill a hole into said block of
wood and use either my vacuum pump or mighty-vac to hold the part down.
Could also make in impression in a chunk of clay, but SWMBO says it would
take at least 24 hours to fire in her huge kiln.
Other ideas appreciated.
13 years ago