Start making a guiding hole to make sure the bearing race will be in the right place.
Use the modified tip drill bit to make the bearing races, the races should be about 1 mm deep for 1/16” steel balls (about 1/3 of the diameter).
The bearing race should look like this.
Resize the inner hole to allow the pivot pin to pass.
The finished bearing race should look like this.
To assemble the IKBS some grease must be applied to the races in order to ensure lubing and help holding the steel balls in place.
Wipe off excess grease in a piece of cloth or paper towel, in order to leave grease only in the race area.
Dip the liner in the steel balls, the grease will stick the balls in place (this is one of the fastest ways to put all the balls in place, if you don’t have enough steel balls you can use a toothpick with some grease to place the balls in the race area).
Pat the liner gently to drop the excess balls and make sure the correct number of them is in place (add or remove the balls according to the case).
Put the washers (optional) and the pivot pin or butt cap in place (you can use some grease to hold the washers in place).
Put all the parts together, be careful not to drop any steel ball and wipe off any excess grease.
Apply some thread lock (loctite or any other brand) in the pivot screw (don’t use too much thread lock, if it reaches the steel balls it may cause some problems).
Finish the assembling, after some time make sure the tread lock really worked by trying to unscrew the pivot, if the pivot is not well locked it will loosen up and the steel balls may end up falling.