Just after coming up with the idea, I walked into the Techshop wood shop and found a pile of thin plywood scraps in the communal scrap bin. I considered this a sign, and decided to get started right away. The rack is made up of pieces with interlocking slots (half-lap joints) cut on the table saw. There is a backer board behind the spice bottles to keep them from slipping out the back.
I'm quite happy with the concept - the shelf fits perfectly, and the spices are much more organized and accessible than before. Of course, there is one obvious problem - not all the spices have labels on the tops. As a temporary solution, I'm going to put sticker labels on the tops that need them. Then I'm going to make some personalized, re-usable spice jars with labels printed on the tops.
Step 1: Tools and Materials
- Table saw * with FTG** (Flat Top Grind) blade OR dado stack
- Crosscut sled
- Combination square
- Grr-ripper - Commercial push block, allows one to safely hold cuts close to the table saw blade
- Rubber mallet
**FTG blades have square teeth that leave behind a flat bottom when they cut - kind of like using a dado stack. Other styles of blade can leave behind a "V" shape wedge, which makes the parts harder to fit together.
- 3/16" thick plywood
- Wood glue
The only reason I used 3/16" wood is because I found a pile of 3/16" scrap. This made a bit more work for me, because none of the standard tools available to me cut 3/16" slots for the joints I'm making - so I have to use a 1/8" saw blade and made 2 cuts. If buying new wood, it's probably easier to use 1/8" or 1/4" wood, because standard saw blades, dado stacks and router bits can all make half-lap joints for those widths.
But it all worked out in the endt - the joints are perfectly tight, and I learned a lot by figuring out how to do things the hard way. If anyone has other methods or ideas, please share them below in the comments.
Step 2: Measure and Model
To check out my idea, I made a quick cardboard model by cutting rectangles the height and width of the shelves, then notching them together to make a grid. The cardboard model worked perfectly - everything fit, and they were accessible just like I wanted. But of course the cardboard was weak, and after a couple minutes started to collapse under the weight of the bottles.
After that, I put my measurements into SketchUp to work out my exact dimensions and how to join them together - then I headed to the wood-shop.
Step 3: Cut to Size
First, I rough cut the parts a bit larger than needed out of my large sheet of material, leaving an extra 1/4" on each part. This is because in the rest of the steps I'm going to be cutting all the same-size parts to final size stacked up at the same time - called "gang cutting."
When working with wood this small, very small differences matter a lot - gang cutting eliminates any guesswork - so even if my measurements are off by 1/32", or my hand slips a little - it will be the same error across all my pieces, and they will still snap together perfectly when assembled.
4 different size pieces
- (1) Back plate - 8" X 12"
- (2) Top/bottom - 3.25" X 12"
- (3) Horizontal shelves - 3" X 11.75"
- (6) Vertical supports + (2) sides (same size) 3" X 8 1/8"
Any time I'm working on a project with similar parts, I take a minute after cutting to label all my parts. This is important to make sure that you cut the right joints in the proper parts - the top / bottom and shelves are almost the same size, easy to mix up. I label them by their use - top / bottom / side/ shelf / support - and also label them by individual project. I'm making two racks at once, so I label the first set "A" and the second set "B".
Step 4: Make Spice Rack Case
- First I measure and mark out 3/16" around 3 edges of the top and bottom pieces using a combination square, penciling the face and end grain to show where I need to cut.
- Second I measure the height of the table saw blade, testing it on a piece of scrap wood to check the depth of cut. I cut ~1/8 deep for these joints.
- Next I start cutting the side rabbets on the crosscut sled. The parts are lined up together to cut them at the same time.
- Nibble away: Since the blade is only 1/8" thick, and my parts are 3/16" thick, I have to cut each rabbet out in 2 or more passes. I start by nibbling 1/16" - 1/8" from the edge of the board, then scoot it over and cut away the rest, testing after each cut until the width of the side pieces perfectly fits the channel.
- Finally I take off the crosscut sled, re-adjust the saw height, and then rip rabbets along the edges of the top / bottom pieces. I set the table saw fence to make a 1/8" rabbet, then move it over 1/16" to remove the rest of the material - this time testing the fit of the back plate after each cut. I used a Grr-ripper push-block to keep my hands safe from any blade accidents, but it's easy to make a simple push block to use on thin stock.
Step 5: Cutting Dados / Grooves
I have 11.5" of usable space for each row of shelves, and I want to divide them into 5 equal parts - the math for this can get a bit complicated, after accounting for the 3/16" thickness of the vertical supports between squares - I tried to do it in my head, I tried doing it by hand with a combination square, but each time I was still a little bit off and the marks were asymmetrical. But then I found an alternative - using geometry!
Remember that old trigonometry your teacher always told you would be useful someday? Well, today is the day! See my other instructable Divide any line into equal parts without measuring
- Take the work-piece to be cut, and draw a vertical line up one side
- Take a ruler and measure ANY diagonal line from the far size of the board to the vertical line you just drew
- Choose a length that can be divided equally by the number of spaces desired. I want to make 5 equal spaces, so I chose a diagonal line 15" long.
- Divide the diagonal line into equal parts - 15 marked at 3, 6, 9, 12 and 15
- Now that the diagonal line is separated into equal parts, use a combination square or 90* angle to transfer the marks from the diagonal line straight down onto the work-piece
After using the geometric trick, I moved back to the table saw and cut out the dados just like I cut out the rabbets - nibble away at the cut in several passes to cut it to size. But I wanted all the dados to be as perfect as possible, since a tight dado will hold the shelves in place much better than a loose one.
To make sure each cut was the same, I set up two stop-blocks on my crosscut sled. I started with a top piece - putting the far edge of the dado against the saw blade, then clamped one stop block. Then I nudged the top piece over 1/16" until the other edge of the dado was lined up with the saw blade, then I clamped down the other stop block. This gave me 1/16" of wiggle room between the two stop blocks. To make each joint, I pressed the piece against one stop block, made one cut, then pressed it against the other stop block and cut again.
After making each joint, I tested the width of the dado with a piece of scrap wood - making sure each joint is perfect now will save time and headache when assembling things later.
One important thing to remember when cutting the top and bottom - the top pieces will be mirror images of the bottom pieces. So whereas I cut the tops with the front edge facing forward, I cut the bottoms with the rear, rabbeted edge facing forward. Technically, there shouldn't be a difference - but this is just like the gang cutting I did earlier - using the same stop blocks in the same position eliminates guess-work and protects you from making small mistakes when switching between parts.
Step 6: Make Internal Shelves
- Before making any cuts, I test out the fit of my parts in the dados. I taped the corners of the case together so I can slide the shelves and supports into place. I'm looking to make sure that the dados fit, and that the inside pieces are the right length.
- I used the dado joints to trace out locations for my notches. I laid a side pieces against one of the vertical supports, then traced across lines to mark the notch width. Then I did the same thing with a top piece and one of the horizontal shelf parts. The shelf pieces are SLIGHTLY smaller than the top and bottom - remember that when tracing.
- Set up the table saw to cut the notches. Each piece if 3" wide, so I want to cut notches 1.5" deep, halfway through each part. Measure the saw blade height, then test it with some scrap wood.
- Set up stop blocks just like those used when cutting the dados, then use the same process to cut notches in 2 or more passes.
- Gang-cut the notches, stacking all the same parts for one shelf together and cutting them at once. Push them against one stop block, make the cut, then slide them all over and make another cut. Before changing stop block positions for the next notch, try fitting the parts together to test the size. I had to re-cut several of my notches when they were too tight.
- Repeat this process until all the notches are cut
Step 7: Assemble the Case
These are the steps I used to assembly mine. The internal shelves and supports, if cut well, don't need any glue - they fit very tightly. I only glued outside case and back plate together at the end - after test-fitting everything together.
- First, get all parts together. Make sure that all the inside parts are facing the right direction. This was the purpose of cutting all similar parts at the same time - making them line up like a puzzle. The first picture below shows one part flipped, not quite matching the others.
- Start fitting the notches together - the first one should be easy - I started with the center notches on my vertical pieces and one horizontal piece
- As you continue to work, there may be some tightness. If the notches won't fit together at all, don't force them. Remove the parts before they gets stuck, and use a sharp chisel, rasp or sandpaper to take off a little material from the notch walls, then try again
- If the parts almost fit together, but just need a little more force at the end - use a rubber mallet or other soft, heavy object to get them closed. If they still don't fit, you may have to take the shelves apart and look for the trouble spot.
- After all the shelves were put together, I slipped the edges of the vertical supports into the dados cut into the top and bottom of the case.
- Next, I slipped the edges of the horizontal shelves into the dados cut on the side pieces
- I put on the back plate, between the top and bottom parts
- After making sure everything fit together, I took the outside case parts off, spread glue in the dado and rabbet joints, then fit them back together. The notches in the internal shelves were very tight and didn't need any glue.