Dowel jig allows in many cases to remove the procedure of markup and punching of the center of holes. Application of the dowel jig can be particularly effective in the manufacture of a series of similar parts, and patterns if you want the high precision of holes. Structurally, the dowel jig consists of the following components: base, handle, reel, jig, screw, nut, bearing pad. Steel drum with a calibrated orifice is fixed on the basis of using the screw and wing nut. Through the centers of the holes and sides should be drawn lines to guide the adaptation.
On the basis, there should be a line too. The handle can be made of the PCB, duralumin, steel, wood and so on. Depending on this should be applied the appropriate method of attachment to the base with screws or bolts. The base of the dowel jig can also be made of different materials, but it is better to use a steel plate. It is better to use figured nut, with knurl or lambskin. The base may have a different form: the usual rectangular (which is not always convenient to work) improved. Quite often, it makes sense to add another node to the device – a guide with details of its attachment. Then it will be convenient to carry out holes located at the same distance from the edge of the details. You may need to change the basic dimensions of the base of the dowel jig. You can provide one more improvement.
Fixture supplemented with the removable node, through which you can drill holes that are exactly in the center line of the workpiece. A node consists of the following components: strap; stop screw (2 pieces). In the bar, there are five holes: two for mounting on a base, two fixing stubborn screws, and one for the exit of a drill. The bar can be made of steel, duralumin, PCB. Resistant screws can be pick up or ready-made (can be, for example, in radios), or buy from turner. At the end of the screw makes the slot to tighten with a screwdriver. Planck of the dowel jig should be made precise: a hole under a stop screw must be placed strictly at the same distance from the middle bracket. Also, the holes in the base of the dowel jig should be done correctly. Only under this condition, you can drill holes right in the middle part. This dowel jig will help you to drill perpendicular holes in the workpiece.
Using the template, you can do exactly perpendicular holes in the plate, in the curved parts of the workpiece and drill a hole in the corner of the workpiece.
Application of the dowel jigs:
Step 1. With the help of core mark the center of the future holes.
Step 2. Put the core in the center of the future hole and put it on the template.
Step 3. Attach the core on the guide sleeve with a diameter of 4 mm wide side up and place it in the template. Center the template and press it with screw-clamp to the workpiece.
Step 4. Remove the core with the guide sleeve from the pattern. In this case, the template must remain motionless.
Step 5. Place guide bush of the desired diameter in the template.
Step 6. Using a drill, make dowel joints of the depth you want.