While building a new workbench, I decided to make my own drawer guides. These guides lock the drawer in place so it can’t fall out. The guides on the drawer are a basic wood runner with one slight difference. The pivoting hardwood block falls down into the gap in the lower case guides (second photo) to keep the drawer from pulling all the way out.
DRAWER RUNNER. The main runner extends from the front of the drawer to the back, stopping 2 1⁄2" from the rear. The secret to these drawer guides is a swing block that pivots down into a gap in the guides when the drawer is opened. This swing block has an oversized hole to allow it to pivot on a screw behind the main runner. A small section of runner is then screwed behind the swing block to complete the runner, as shown in the left photo above.
CASE RUNNERS. The runners inside the case are made up of four pieces; upper and lower guides and a pair of stop blocks. The lower guide extends from the back of the case stopping short of the front. A gap is left for the swing block on the drawer side to drop into. The stop block is then screwed into place. The upper guide is attached in the same manner, with a gap being left to allow some clearance for the swing block to pivot (second photo). The drawer can then be inserted into the case.
REMOVING THE DRAWER. When you pull the drawer out, the swing block will drop into the gap in the lower guide and hold the drawer in place. In order to remove the drawer, I drilled a small hole through the drawer side into the swing block. With the drawer half way out, I can slip a small nail through the hole into the swing block, keeping it from dropping into the gap (first photo). This allows the drawer to be completely removed from the case.
How it Works
Drawer Closed. The swing block will pivot in line with the drawer runner and allow the drawer to close. The offset gap in the upper guide allows the corner of the block to pivot into place. Drawer Opened. When the drawer is pulled open, the swing block will pivot down into the gap in the lower drawer guide. In this position, the drawer is locked into the case.