How to make a jig

This is a guide to making jigs, using the example of a card picket fence on the model shown here. Always use a cutting mat and safety rule when using a scalpel.

Cutting the pickets

1. Using a ruler and knife, mark a number of 4mm divisions on either end of the card.
2. Line the ruler up with the knife marks on the card and cut the card with a series of shallow cuts until you have cut all the way through.
3. Repeat this until you have cut all the strips.

The first strip you cut is often a slightly different width to the others, so you may have to discard it.

Making the picket jig

For this jig we used 1mm styrene.

1. Cut a piece of styrene big enough to make the base of the jig, in this case 30 x 120mm.
2. Cut a 10mm strip of styrene to form the sides of the jig.
3. Make a cut at approximately 35° on the end of the 10mm strip.
4. Mark the length of the picket on the styrene, measuring from the pointed end, and make a right-angled cut using an engineer's square.
5. Using the cut piece as a guide, cut the same 35° angle on the 10mm strip.
6. Then, using the cut piece, mark the length on the 10mm strip.
7. Cut the 10mm strip to the same length using the engineer's square.
8. Glue one of the angled pieces onto the base with plastic weld.
9. When it is dry, place a strip of the card against the glued styrene and glue the other piece of styrene onto the base, making sure the pieces of styrene match up exactly.

Using the jig

1. Insert the card strip into the jig.
2. Making sure the strip does not move, cut the first angle.
3. Cut the second angle, then the length, to complete the picket.
4. Remove it and repeat until there are enough pickets to make the fence.

Cutting the rails

1. Using a ruler and knife, mark a number of 3mm divisions on either end of the card.
2. Line the ruler up with the knife marks on the card and cut the card with a series of shallow cuts until you have cut all the way through.
3. Repeat until you have cut all the rails.

Making the gluing jig

For this jig we also used 1mm styrene.

1. Cut a piece of styrene big enough to make the base of the jig, in this case 300 x 50mm.
2. Cut two 15mm strips of styrene to form the top and bottom of the jig.
3. Cut a 9mm strip of styrene, which will space the rails apart.
4. Cut a 10mm strip of styrene, which will make sure the pickets are level when they are glued.
5. Glue the first 15mm strip, the bottom of the jig, onto the base with plastic weld, making sure that it is glued exactly along the edge of the base.
6. When it is dry, place one of the rails against the 15mm strip and glue the 9mm strip against it.
7. When the 9mm strip is dry, place another rail against it and glue the other 15mm strip, the top of the jig, to the base.
8. With a pencil, mark 9mm divisions along the top of the jig.
9. Using the engineer's square, draw lines across the jig from the division marks.
10. Glue the 10mm strip to the bottom 15mm strip.

Assembling the picket fence

1. Place the two rails in the jig.
2. Using the pencil marks as a guide, put a dot of glue on each rail.
3. Glue a picket onto the rails, using the lines to keep the picket straight and the 10mm strip at the bottom to keep all the pickets level.
4. Repeat, gluing on pickets until the fence is complete.

Products used

• Plastic Weld solvent
• Fast Tack glue
• A fine-hair paint brush, size 5
• White card, 1.2mm
• White styrene, 1mm
• A No. 3 scalpel with 10A blades
• An A4 cutting mat
• An engineer's square, 50.8mm (2in)
• A safety rule