Clamp Knob for Lee Press

thingiverse

The popular Lee Precision Benchplate is used to hold a Lee press to a workbench. The plate is held in place with a clamping system that locks with four 1/4" screws. These knob screws provide quick loosen and tighten with no tools and no lost screws. Use support when printing the knob. I used PLA with good success. Place the knob on the printer with the large end against the bed. You'll need support in the cavity where the head of the screw goes. This is easy to remove. Be sure to remove the bottom layer of the support as it can look like the bottom of the cavity and it will prevent the screw from protruding sufficiently. If you use the .STL file, the slicer may need to know that it is dimensioned in inches and must convert to metric. The 3MF file works as is in my Prusa slicer. A dozen of these knobs printed in a space about 15cm in the long direction. In addition to the 3D printed knob, you'll need a 1/4 x 1-1/2" screw, preferably with a hex socket head, a flat washer and a brass threaded heat-set insert. Press the brass heat-set insert nut into the bottom of the knob with a soldering iron or gun. If you put the screw through the knob and thread the insert onto it first, that will hold the insert firmly against the bottom of the knob and get it started straight. I used a generous amount of Lok-Tite to lock the screw into the heat-set brass insert. You should have 1/4" of thread exposed after assembly. This is moderately important because less than 1/4" will give very little engagement into the clamp and more than 1/4" will prevent the screw from tightening. There's some wiggle room and the thickness of the washer can be used to fine tune the assembly. The Amazon links are as follows: 1/2-20 x 1-1/2 Screw. https://tinyurl.com/ycujvqkc. (individual screw) https://tinyurl.com/y9w88u6p. (large kit of 1/4-20 screws, nuts & washers) Brass Threaded Insert. https://tinyurl.com/ya8mdtjh