Drill guide
A method of joining together a first and second workpieces. The method comprises; drilling a first hole at least partially through the first workpiece with a drill bit oriented in a first direction; drilling a second hole at least partially through the first workpiece with a drill bit oriented in a second direction which is not parallel with the first direction, the drill bit passing through the first workpiece into a side of the first hole; inserting a fastener through the second workpiece and into the first hole; inserting an anchor into the first hole via the second hole; and securing the fastener within the first hole with the anchor. The invention also relates to a drill guide for use in such a method. The drill bit is aligned by placing a target magnet in the first hole without completely filling it; placing a drill guide with a guide magnet or magnetic field sensor next to the first workpiece; adjusting the position of the drill guide until the guide magnet or magnetic field sensor indicates that the drill guide is aligned with the target magnet; and drilling the second hole by passing the drill bit through the drill guide and at least partially through the first workpiece, the drill bit entering the side of the first hole at a location where the first hole is not filled by the target magnet.
1. A method of joining together a first and second workpiece, the method comprising; drilling a first hole at least partially through the first workpiece with a drill bit oriented in a first direction; placing a target magnet in the first hole without completely filling it; placing a drill guide with a guide magnet or magnetic field sensor next to the first workpiece; adjusting the position of the drill guide until the guide magnet or magnetic field sensor indicates that the drill guide is aligned with the target magnet; drilling a second hole at least partially through the first workpiece with a drill bit oriented in a second direction which is not parallel with the first direction, the drill bit passing through the drill guide and through the first workpiece into a side of the first hole at a location where the first hole is not filled by the target magnet; removing the target magnet from the first hole and the drill bit from the second hole; inserting a fastener through the second workpiece and into the first hole; inserting an anchor into the first hole via the second hole; and securing the fastener within the first hole with the anchor.
2. The method of claim 1 wherein the drill guide comprises a guide magnet.
3. The method of claim 1 wherein the target magnet is oriented with its north-south axis substantially parallel with the first direction.
4. The method of claim 1 wherein the fastener comprises an anchor hole; and wherein the fastener is secured by inserting the anchor into the anchor hole.
5. The method of claim 1 wherein the first hole is drilled in the first workpiece by passing a drill bit through the second workpiece and into the first workpiece.
6. The method of claim 1 wherein the first workpiece comprises a rib for an aircraft wing.
7. The method of claim 1 wherein the second workpiece comprises a skin for an aircraft wing.
8. The method of claim 1 wherein the target magnet is placed in the first hole by passing it through the second workpiece.
9. The method of claim 1 wherein the target magnet is provided on the shaft of a target pin; and wherein the target magnet is placed in the first hole by passing the shaft of the target pin through the second workpiece and into the first hole until a head of the target pin engages the second workpiece.