Expandable Bracelet

Turn one of these beautiful bracelets for a special girl in your life and leave everyone else wondering how you drilled those tiny little holes around a curve. 

We all love going to the wood specialty stores and drooling over all the pieces of wood from around the world, but not many of us can afford to buy them. These stores often sell tiny little boards that aren’t big enough to do anything with. This is the perfect project to try using some of these cool exotic woods, or use up some of those small scraps that you haven’t been able to part with. You can’t get in trouble for buying expensive wood when it’s for her.

The first thing you’ll need is the wrist size of the lucky lady who will be wearing the bracelet. If you’d like to surprise her or you don’t want to frighten her, do not try to obtain this mea­surement with a set of callipers. Take the measurement across the width, just behind the hand. Remember, the bracelet will stretch over the hand and is to be a snug fit.

Once you have this wrist measurement you can start to draw the bracelet. Starting with the inside diameter, draw the brace­let as a circle with a compass. Draw a second circle, as your wall thickness, around the outside of your first circle. I used a 1/4″ wall thickness. Draw in a 1/16″ wide dado, evenly spaced between the inside and outside of the bracelet.

The design possibilities are endless. I used Purpleheart and Macassar ebony separated by two maple veneers.

Cut your two outside blanks a little bigger than the outside diameter of the bracelet and glue them to a sacrificial block. Glue a maple veneer to both halves. Alternate the grain direction of the veneer to the solid wood by 90°. This is called cross-banding and will give the bracelet the necessary strength across the grain. Use a block covered in packing tape or a piece of melamine to press the veneer flat. These clamping blocks will resist the glue if it should bleed through or squeeze out.

Follow the glue manufacturer’s drying times to allow the glue to cure properly before you continue working with the piece.

Use a four-jaw scroll chuck to mount the work piece on the lathe. Once the piece is running true, use a sharp pencil and a ruler to transfer your measurements from the drawing to your work piece. Mark the center point and scribe the inside and outside diameter as well as the dado.

At this stage you want to leave as large a gluing surface as pos­sible, and only cut the dado. Use a narrow parting tool to cut the dado 1/16″ wide and 1/16″ deep. Repeat this dado on the other out­side piece, being careful to make the dado the exact same size.

Once the dado has been cut, cover the face with painter’s tape. Use a sharp exacto knife to score around the inside and outside of the dado.

After the tape has been removed from the dado, be sure the tape is stuck down and is protecting the face of the blank. Use a putty knife to pack the dado with Waxilit, a glue-resist that is available from Lee Valley. You must be very careful not to get the wax anywhere but in the dado. Remove the tape from the face of the blank. Be sure that there is <em>no </em>wax anywhere but in the dado before gluing to the middle section of the bracelet. Put the glue on the middle section and be careful not to slide the pieces around too much. The idea is to keep the wax in and the glue out of the dado.

After the glue has properly dried, remount this section on the lathe and true it up. Check that the face of the middle piece is flat before gluing to the other outside half. It is easiest to line up the two parts if they are both the same diameter. Once again, alter­nate the grain direction of one piece to the next by 90°.

You can now turn the bracelet to its final dimensions. Proceed with care, take fine cuts, and keep a close watch on your inside and outside diameter to make sure you don’t turn in too far. Remove the first glue block with a parting tool.

Use a forstner bit to drill out the mid­dle of the bracelet. If you want, I guess you could try making a ring out of the middle. I think it’s bad enough we are making bracelets so I opted for sawdust.

Once you have turned and sanded the inside of the bracelet, remove the last glue block.

You will have to clamp the bracelet from the inside with your chuck to do your final cuts and sanding on the out­side. Be very careful when using your chuck for internal clamping because the tightening and loosening operation is now opposite to what you are used to. Make a diagram to show how to tighten and loosen when clamping internally (expan­sion). This will help you from turning the chuck key the wrong way and snapping this fragile bracelet. Add a slight bull nose profile to the bracelet and take the sharp edge off the inside.

Turn a hole the same diameter as your bracelet in a square scrap of wood to make a custom mitre box to cut your segments evenly and at 90°. Leave the outside of the mitre box square so you can mark out your first cut at 90° to the bracelet and 90° vertically. Use a fine tooth back-cutting razor saw. Mark the mitre box diagonally from corner to cor­ner and use this line to cut eight even segments.

Use a paperclip or a toothpick to help push the Waxilit out of the dado. Use compressed air to force the remaining wax out of the dado. a hard sanding block to sand out the saw marks and put a very slight chamfer on each piece.

As you cut your pieces off one at a time, keep them in order by stringing them onto some fishing line. You want to keep them in order so the grain will all line up once re-assembled.

Use the fishing line to hang the pieces up like a clothesline. This will make it easy to give them a blast of clear coat from a spray can.

Buy some 1mm elastic jewellery string from a craft store and re-assemble the bracelet with the elastics. Tie a tight knot, trim the excess and carefully pull the knot into one of the segments.

Your bracelet should now stretch apart and then hold its shape on its own. All that’s left is to give it to the lucky lady, who will no doubt appreciate all of your hard work. Good luck and happy turning!