SummaryThis is a knob designed to encase a 1/4" hex head cap screw. Because it can be used with any length cap screw, it's useful in a wide range of applications. The plug covers and secures the screw while making for a nice finished look. Works great as a camera or flash mounting knob. The plug is designed with a lip to snap into the knob and hold the screw in place while it finishes the look of the knob. You will have to print the plug at a reduced size to make it fit correctly into the knob. Because everyone's printer prints slightly different, I have not tried to size the plug exactly. You will need to run the plug at a few XY scales to make the fit perfect. For me running the plug at 96% works great. It is designed for a 1/4-20 screw but could also be used with a 6M screw if printed at approximately 95%. I have not tested this but it should work with a range of screw diameters by changing the print scale to match the screw diameter.Instructions Print the knob part. Print the plug at a reduced size (see notes above). Insert the hex head machine screw. If the screw fits loosely, it can be secured with a few drop of epoxy around the hex head. Snap the plug in place. The larger lip of the plug goes in first. Start the plug at an angle to seat one side and then press the high side in with a vice or pliers. The knob has a recess that matches the plug so it should hold in place without glue and be removable by taping the screw out.