Thursday 25 September 2008
Make this smart CD rack by Anthony Bailey
Most people accept that music CDs give perfect sound, but storing them is another matter. As my collection grew into an unruly pile on
the floor I finally gave in and made a revolving CD rack in ash which holds 40 CDs. It takes up a limited amount of room, and looks good anywhere in the home.
The slant of the slots holds the CDs in place and makes for a more dynamic design when filled. This gives a bit of complexity to the design, but a challenge is nothing to be scared of!
Setting outThe key to making this rack is the setting out. You have to know exactly what size the components need to be, and have
accurate spacings for the slots.
Start by drawing a side panel showing slots for 10 CDs. Mark even spacings between, plus 5mm extra at each end - this will be the length of the tongue which locates each panel into the top and bottom.
I decided on an 11.5mm (29/64in) slot width to comfortably slide a CD in, and a 9.5mm (3/8in) gap between, with each slot 8mm deep. The slot angle is 35 degrees, resulting in a panel 326mm (12 51/64in) long by 95mm (3 47/64in). Accurately prepare some 20mm (25/32in) thick ash (finished size). All parts must be identical and square.
SlotsMake a jig from 6 to 9mm (1/4 to 3/8in) thick ply, with an angled slot towards one end to allow a guide bush to run in. I used a 9.5mm straight cutter with a 17mm guide bush. Any suitable combination will do, providing you make a test slot first to check that you can create the 11.5mm (29/64in) width CD slot needed.
Machine a short angled slot next to this, the width of a CD slot and the correct distance from the centre of the guide bush slot. This will give an exact reference position for each successive slot you make.
Screw two strips of wood on the underside so the blanks fit tightly between. Make a test piece first. Position the blank so one end is just in line with the edge of the guide bush slot and cramp in position.
This should leave just enough at the end to form the 5mm (13/64in) tongue. Once the first slot is made, uncramp and slide the blank further underneath so it appears underneath the reference slot in the jig. Reclamp, machine the next slot, and so on.
Side strips should prevent the wood breaking-out at the end of the slots. Create four blanks in this way, then fit the side strips on the other side to create the other four that are a mirror image of the first four. Stick some abrasive on a board to keep it flat and sand all sides and edges of the components to de-fluff them.
Top & bottomAccurately mitre together each of the four pieces needed for the top, bottom and the base. This is quite an undertaking and will show just how good your work and mitre saw is.
A fine-tooth blade, careful setting up, and a test piece are needed to verify that you can get good accurate meetings of all the joints.
The top and bottom can just be butt-glued together, but the base, which is thicker, needs two rows of biscuits for strength, this is because it carries the whole weight of the rack and the CDs. The slots for this are produced with a jointing cutter used in the table.
TonguesDraw a full-size master drawing or 'rod' of the plan view on a board. I like using white MFC, melamine faced chipboard, the lines are clearly visible and you can use an eraser if you make any mistakes.
Note how the panels sit in pairs offset to each corner, leaving an unfilled space in the middle. This needs a 58mm (29/32in) square piece of ash to complete the equation.
Draw on the 'rod' 6.4mm (1/4in) wide strips aligned to the inside of each panel where their housings will be situated. The tongues on each panel will be flush on the inside slotted face as a result.
Now make a ply jig with slots to take a small guide bush in combination with a 6.4mm straight cutter. The jig will need two good meeting edges at 90 degrees to each other as it fits flush at the back right-hand corner when clamped on the bottom panel.
The two slots are at the front left-hand of the jig, and there is extra board to the front and side for the router to sit on. The resulting slots on the top and bottom ash panels must match those on the rod exactly, and stop just short of the panel edge so the housed joint is hidden.
Each slot runs slightly beyond the panel at its back end, so the square end of the tongue fits easily into the slot without having to round the tongue or trimming off.
Cut the pieces for the top and bottom panels and the base exactly to their respective sizes, ensuring that the finished corners meet exactly at their mitred junctions in each case.
Using the router and a straight-edge, mark the correct offset for the cutter to edge-of-base distance. Place the jig on the bottom panel and cramp in place so the back right-hand corner and edges line up together.
Rout this and the previous operation by 'routing the plank' as mentioned in the sidebar. Machine the housings 5.5mm (7/32in) to 6mm (15/64in) deep to leave clearance for the end of the panel's tongues. To cut the housings in the top panel, which is a mirror image of the bottom panel, flip the jig over and mark the critical corner, then rout all four sets of slots as before.
Check that each panel sits in the correct position, flush with the edge of the top and bottom panels and the right width apart to take the CDs cases.
Index stickAll the vertical joints between the panels and the ash 'core' in the middle are made with No.10 biscuits to prevent breakthrough.
Use three per edge and make an index stick with lines 25mm (1in) apart which the cutter must run between to make the slot long enough for the biscuits to fit.
Fit a small block at each end of the index stick so it fits tightly on each blank. Now you can offer each piece up to the cutter in the table and machine the slots exactly, without marking them all individually.
Some joints are on the edges, others are on the unslotted panel faces, so take care in checking which you are doing.
The face slots need each panel to be held vertically as you push it onto the cutter. Always place the furthest end of each panel against the fence first. Don't allow the panel to move backwards over the cutter or it may fly out of your control.
Always swing the panel right away from the cutter once each slot is made so you don't graze the wood between the slots.
The square core piece is 10mm (25/64in) shorter, so adjust the blocks accordingly. All like components will be interchangeable as a result of using the index stick.
Dry fitDry fit everything to check that it goes together, then sand all internal surfaces to a finish, taking care not to round over any edges. De-fluff the slots with a folded piece of abrasive paper.
Glue the central panels onto the square core first inserting biscuits and ensuring glue doesn't seep out on the slotted face, if it does wipe it off thoroughly with a damp cloth.
Cramp and check all panels are at 90 degrees to the core piece. Sand the resulting flush surfaces flat. Next glue and biscuit the other panels on and check with a square. Any failure to get this right means the whole thing will not go together when the top and bottom are fitted.
Now glue the top and bottom on, cramp well together and leave to dry.
Bolting upThe base must be cut to an octagon, close to the marked lines, then trim with a router and straight-edge. Machine with the grain to avoid tearout.
The CD rack swivels on a large bearing, and a long bolt with nut that fits, in this case a 10mm internal bearing diameter. Draw around the bearing, placed dead centre on the base, take a router and large straight cutter and freehand rout by holding the base.
Work up to the line and check the bearing fit. Adjust by routing until it is a hammer-tight fit. Don't knock it right in or you may not get it out again. If you have a jig passion it would be possible to make one for this process but I decided it would be quicker to rout freehand.
Fit the bolt in the bearing and tighten the nut. Now make a further recess underneath so the bolt head will turn freely. Sand the CD rack to a finish all over, use filler for any flaws or slight gaps, if needed.
FinishingUpturn the CD rack and mark dead centre. Take a big router with a long 9.5mm cutter, stick some abrasive on the router base so it won't slip around, and make a neat full-depth plunge to drill the bolt hole.
If necessary, trim the bolt to fit the hole and file a bevel on the end to help it start threading, then wind it in with a spanner.
Apply a suitable finish such as sanding sealer or spray lacquer (nothing oily though), tap the base onto the bearing and apply some protective felt or baize. Stand the rack up the right way - it's done!
The last and most vital bit is to fill up the CD rack, pour yourself a nice cold drink and unwind after the stress of this project, listening to your favourite tunes!