How to play
- Drag each part from the pegboard onto the door or the jamb. A green ring means it can go there now; red means something has to go in first.
- Before the latch goes in, tap its bolt end on the board to flip the bevel, and its tube end to switch the backset between 2-3/8″ and 2-3/4″.
- Tap a fitted part to take it back off. Parts that hold it in have to come off first.
- Press Close the door. If it latches, the inside lever opens it, then the push button locks the outside lever. If not, the door shows you which part is wrong.
- No dragging? Use the Fit, Remove, Flip and Backset buttons in the parts list.
What the puzzle teaches
- Cylindrical locksets use a 2-1/8″ cross bore through the door face and a 1″ bore into the edge.
- Backset is the distance from the door edge to the centre of the cross bore, usually 2-3/8″ or 2-3/4″. Adjustable latches are set to match.
- The latch bolt's bevel faces the stop, the direction the door closes, so the strike pushes the bolt in and it springs back into the strike hole.
- The latch goes in before the outside lever, because the lever's spindle and posts pass through the latch housing.
- Through-bolts go through the inside rose into the outside lever's posts and pull both sides tight to the door.
- The latch faceplate and strike plate sit flush in shallow mortises, held by two screws each.
Parts on the list
- Lever or knob lockset (outside lever with spindle and posts, inside lever with rose)
- Adjustable latch, 2-3/8″ / 2-3/4″ backset, and 2 latch screws
- 2 through-bolts
- Strike plate (with dust box) and 2 strike screws
- Door prepped with 2-1/8″ cross bore and 1″ edge bore
This is a planning and training aid. Follow the lockset maker's instructions and template.