I live in tight quarters with my family, and lately we've been practically tripping over each other's stuff. I've been tasked with organizing the apartment by any means necessary, and in this instructable I'll show how I got things started with an entryway bench that doubles as a shoe organizer.
I've seen built-ins like this in mudrooms, but hadn't seen a free-standing unit, so I went searching for ideas online. I found a lot of interesting designs on Pinterest and made a rough sketch, but then I also stumbled on another instructable made by another Techshop (my local makerspace) member dogtooth - (see it here).
My original design was a bit boring, so I decided to incorporate dogtooth's idea of decorative vent holes into my bench. Right now the top is bare, but the low lip all around the seat will eventually enclose a pillow top that I plan to sew in the next week or two.
If you like this, vote for it in the Wood or Small Spaces contest! Thank you!
Step 1: Tools & Materials Used
I used a CNC to cut out all the shapes for this project. The basic shape of each piece could just as easily have been cut out using stationary or handheld power tools, however the large number of vent holes in my design are much easier to cut with a CNC than traditional tools, at least with my current skill level.
- Shopbot Alpha CNC machine - with 49 X 96" table
- 1/4 inch downcut spiral endmill (+ 1/4 inch upcut endmill optional)
- Bosch orbital sander
- Sewing machine
- Hand file
- Rubber mallet
- Sketchup *
- Illustrator (Inkscape = open source option)
- VCarve Pro (any good open source CAM options?)
* A note on Sketchup - I'm using the pro trial since I drew this on a new computer. The free "Make" version does not include cad-format export by default, making it harder to export faces for CNC cutting. You can find plugins for this capability, or use a different modeling program.
- 1/2 inch plywood (for bench body and rack sections)
- 3/4 inch plywood (for seat)
- 5-minute epoxy (wood glue also can be used, but I had a special reason for using epoxy)
- Gloss/semi-gloss polyurethane
- Mineral spirits
- Boiled linseed oil
Step 2: Design
First I measured the area. I wanted it to be a little longer but given the orientation of the hallway, I chose to squeeze it in a little area just by the kitchen entrance. I ended up making it 28 inches wide X 16 inches deep X 20 inches tall (seat height is at 20 inches, including the cushion).
I drew the whole unit using Sketchup. I made each component separately, a total of 7 pieces. This allows me to grab the face of each piece later and use it for the basis of a CAM (computer aided machining) program to run my CNC machine.
I exported the faces of each component as a DXF to a vector progam (Illustrator) to make sure all the lines were clean and ready for machining. I've included both the sketchup and Illustrator files in this step
I opened the vector file in Vcarve pro (the user-friendly CAM program of choice at Techshop) and then set up my machining paths. I've included both the sketchup file and my Illustrator vectors. If anyone wants a different format let me know and I will try to accommodate it.
Step 3: CAM File Cleanup
My joints (mortise & tenon, the little tabs and slots where parts snap together) are perfectly sized in the file, but I need to make one alteration to work with the CNC machine, I had to add little notches to the side of all the inside corners for my mortise and tenons. This is because CNC machines use rounded cutters, which leave behind rounded internal corners. If you don't create an allowance for each tab (mortise) to slide in, the corners will stand out and the pieces can't fit together flush.
VCarve has a tool just for this type of operation - the fillet tool. There are different styles of fillets, but I chose to use the "dogbone" fillet - which makes small divots in each internal corner.
Step 4: CAM Settings & Tooling
I created two tool-paths for my parts - a profile tool-path to cut out each part and create the ventilation holes, and a pocket tool path for the mortise holes.
I used one tool for all operations, which worked okay - though in the future I will try using two tools for similar work for comparison. The tool I used was a 1/4 inch down-cut spiral endmill. I used this because, of the tools I have available, I figured this would give me the best surface finish on my parts. I'll explain the difference between downcut and other endmills below - but first...
- RPM - 12,000
- Stepover (for mortise pockets) - 50%
- Feed speed - 3 IPS (inches per second)
- Pass depth - 0.17 inches (cuts JUST through 1/2 inch plywood in 3 passes)
Upcut? Downcut? Compression?
Typical endmills are "upcut" - which means they pull debris out of the cut as they rotate. This is fine for many materials, but in plywood it often creates splintery tear-out along the whole top of the cut.
Down-cut endmills, on the other hand, push debris down into the cut as they rotate. This avoids tear-out on the top of the cut, and in thin material can be used as an hold-down assist method - the chips piled up in the cut cushion the cut piece on all sides. However, you must be careful to avoid packing in too many wood chips, which can jam the cutter or burn up. To avoid this problem I used compressed air to blow away chips from the first two passes, and let the chips pile up on the final pass to dampen the cutting vibration.
The other downside of the down-cut endmill is that it can leave a slightly messy surface on the BOTTOM of the piece, if you are cutting all the way through. This wasn't a deal-breaker for me, but it did generate a bit of extra work in the middle of the project. Beneath my workpiece there was a fresh MDF spoilboard - that helped a lot because the MDF supports the wood fibers underneath and prevented my cuts from splintering badly. However there was a lot of flashing that had to be filed and sanded off the bottom of my pieces.
Compression bits are the final style of endmill. They combine an upcut and downcut bit into one tool. When used properly they can create very clean faces on both sides of the material. The downside is that they are very expensive (perhaps $50-$75 per bit, compared to my $20 tooling) and you get the most benefit by cutting through the material in 1 pass - easy for some machines, but pushing the limits of my setup.
One final approach that I will try using in the future is a two-step approach, using a downcut bit for my first pass, and an upcut bit for the final pass. The tool change process isn't too painful, and at this point I'm mostly using these tools for personal projects, not production work, so I can sacrifice some time.
Step 5: Cutting Out the Parts
I cut the parts out of two pieces of material - I started by cutting out the seat from 3/4 inch plywood. I used a thicker material for the seat because I thought 1/2 inch material might be prone to flexing under the weight of an adult sitting on it.
Since I used only a downcut bit, it was important to have a good, flat spoilboard under my sheet. Thankfully there was a brand new piece of MDF laid down on the table. We're allowed to make extremely shallow cuts into the base MDF - I try to keep mine at 1/100th of an inch or less. However, in a shared shop like Techshop people don't always follow the rules, and the spoilboards can often be left a carved up mess.
For both pieces of material, I secured them to the table with 1.5 inch plastic (Raptor) nails. This is a preferred method of work holding at my shop, aside from using self built jigs / fixtures.
The whole cutting operation took about 1 hour - the seat took 12 minutes, while the rest of the bench took 45 minutes, plus some time for setup and cleanup
I used tabs to hold my larger pieces in place, though I let some of my smaller cutouts (the waste from the vent holes) float free. This was a gamble, but everything went fine - the small amount of chips I let build up in the cuts helped hold the small waste pieces in place so the machine didn't grab or throw them - though that could be a bigger problem if I used an upcut bit instead.
Step 6: Breakout & Cleanup
After all the parts were cut, I used a chisel and rubber mallet to break each of them free from the tabs. Then I peeled the rest of the material free from the table and cleaned up the machine.
As you can see, each part had significant fuzz on the underside, especially around the vent holes. This was the effect of the downcut bit I talked about earlier. This flashing took a bit of time to clean up with hand files and sandpaper, but it wasn't so bad because the cut didn't damage any of the finished parts by splintering the wood, just left extra material behind.
After I had all the parts cleaned up, I tried dry-fitting everything together to make sure all the joints were cut correctly. You can see my brother helping to fit the parts together.
I breathed a sign of relief when it was all cut - I was able to make all the joints fit together nice and tight. I did have one scare during this step, however. It seems that I managed to make a mistake in my original model - I placed the mortise and tenons slightly off-center, so the rear panel of the bench is not quite symmetrical. This caused some minor assembly problems, but thankfully it was just close enough to work - I've now modified the files to fix the mis-alignment.
Step 7: Edge Banding
Edge banding is a thin roll of real wood veneer with iron-on glue applied to the back. It allows one to cover up the natural striped edge of plywood with the look of solid wood. This step is purely aesthetic and optional, but it was something I thought would help this project, and also an excuse to try edge banding - I've used it for crafts, but never applied it to a finished furniture piece before.
The glue on the back is heat-activated, so to apply it I cut it a bit over-size, then used a dry iron at the maximum heat setting to bond the banding to the edge of the plywood. I used 13/16th inch banding, which is perfect for the 3/4 inch seat, but a bit of a waste if used on 1/2 inch material. It works, it just gives you more to trim away - I used it becuase I already had the banding from another project.
When applying the banding take care to apply it straght along the whole edge - I had to remove, sand, and re-apply my banding to one shelf section because it started going diagonal, running off the edge of the plywood at the end.
Step 8: Sanding and Finishing
If I do a project like this again, I will try and spring for pre-finished plywood. As long as you can keep the cut edges clean, prefinished plywood seems like it would save a lot of time and effort. In my case, I bought this plywood directly from Techshop and they were out of pre-finished at the time, so I made do with it.
I chose to pre-finish the bench before assembling it, using a custom (polyurethane) wiping varnish mixture. Pre-finishing before assembly is a good policy when working on any project with tight spaces or inaccessible corners, as most finishes are prone to pooling in the corners of assembled pieces.
If you plan to assemble a project like this with wood glue, you need to take care during finishing to tape-off and protect the joints (mortise and tenons here) from getting covered in finish, because wood glue doesn't stick well to polyurethane. In my case I didn't do this and I went ahead and used epoxy for my joints.
My plywood was pre-sanded pretty smooth, but some of my parts had work-marks on the outside faces where I had to clean up flashing, so I sanded it to make sure and eliminate tool marks.
The varnish I used was a mixture of semi-gloss poly-varnish, "boiled" linseed oil, and mineral spirits. I added linseed oil to warm up the color of the wood, and I thinned the varnish to make it easier to apply a smooth, even coat by hand.
- I sanded all the pieces with 220 and 320 grit sandpaper using my orbital sander set to a very low, non-aggressive, speed. This is often only an option with higher end sanders - cheap sanders are often stuck at one, fairly aggressive, speed. If you don't have a gently sander, it's fine to hand-sand as well. Just make sure to use a good sanding block and sand WITH the grain to minimize marks.
- After sanding, I wiped the surface down with a rag soaked in mineral spirits. This helps pick up any specks of dust that could mar the finish.
- I soaked a lint free rag in the mixture and used long, even strokes to apply the finish. It's not important to make the first coat look pretty - much of the varnish will soak into the wood instead of sitting on the surface. Just make sure all areas are covered. Wait a few minutes, then wipe off the excess varnish with another rag.
- Let the pieces dry for several hours, they should be dry and not sticky to the touch before continuing.
- After the pieces dry, lightly sand with 220 grit sandpaper to knock down any uneven spots or fuzzy fibers that stand up. Then apply a second coat of wiping varnish, wait a few minutes, and wipe off the excess, as before.
- Repeat these steps as necessary until you build up the desired level of finish. To increase buildup, you can reduce the amount of mineral spirits for a thicker coat - just take care with thicker varnish to not leave behind wiping marks.
I used a total of 4 coats on the outer faces and 2 coats on the inner faces.
Step 9: Assembly
To assemble the bench I used 5 minute epoxy and a rubber mallet. If I were to do this again I'd use a slower setting adhesive - either 30 minute epoxy, or perhaps I'd protect the joints from varnish and use wood glue. The 5 minute epoxy works fine, but it was a lot of pressure to get things fit once I put it on the wood.
- I mixed up a batch of 5 minute epoxy. Make sure to make enough for the whole job, I did, but just barely - you don't want to waste time re-mixing in the middle of assembly.
- I put epoxy in all the mortises on one side of the bench. I then used my mallet to hammer each of the cross-parts into place. I was worried the parts might not fit with the added varnish, but they worked just fine.
- After all the cross parts were attached, I hammered the back panel into place. It was a bit hard to make the tenons align across two different planes, but I was able to do it.
- Finally, I attached the opposite side of the bench. This was the hardest part. Fortunately my design came together well, so all the tenons were well aligned with all the mortises, but it was hard to get them all inserted at the same time. I had to make 15 different tenons line up with 15 mortises, and they all had to pop in at roughly the same time. As soon as I hammered down one side, the other popped up.
- I solved this problem by going around the assembly in a circle, gently tapping each tenon into place just a little at a time. Once they were all at least halfway seated I got more forceful.
And that's it! I will actually be updating this instructable in a week or two showing my addition of a pillow top for the bench.