project within a project within a project-
making a hybrid drawbolt. what i needed was a long bolt, an 8mm allen socket with 3/8-16 threads. not a common item.
whats a drawbolt? its a long bolt that goes through the spindle of a milling head that secures a tool on the other end. in this case the drawbolt will screw into the end mill holder seen in the previous post.
starts out as a common long M10 bolt
next the existing threads are cut off and the center gets drilled out
then we turn down some 3/8-16 all thread
they fit together nicely
i inserted a piece of silver into the hole, fluxed, heated, soaked, and wire brushed. the oddball bolt is done.
now here is what the drawbolt i made does-
the bolt goes through the spindle
a toolholder with an external taper fits into the internal taper on the other end of the spindle. it is threaded on.
then we tighten the bolt and it draws the toolholder into the spindle for a nice tight interface
then something is fixed into the tool holder, in this case the hole saw arbor i made yesterday.
almost fork time....