If you have a table saw, you can rip strips off a 2x4 stud. Doesn’t have to be fancy wood. The solid wood hides the plies, and the thicker (taller) dimension adds rigidity. It’s done with bookshelves all the time.
Slotting plywood together
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Unfortunately , I only have a few hand held power tools, such as a circular saw etc. And I dont have a workshop, so I have to wait till the weather is fine enough to set up my work bench outside - but thanks for the tip. One day when I can get a good set up, I'll do that
If you find a good deal on a router then look around for a 9mm straight router bit with 1/4" shank. Likely online as I've never found metric bits at my local sources. Otherwise a 1/4" straight bit and two passes can make a 9mm wide slot. Something to clamp down a straight edge (a couple of small C-clamps) and place to set your coffee while you work. Before I had a shop space I bought a Black and Decker Workmate folding bench. I still have it and use it often. Great work holding built in.
4D
4D
Thanks for all the help everyone.
I just found a used handheld cordless router on ebay!
And would this router bit be ok to cut the slots on the 9mm plywood?
Looking forward to getting started on this. I'll post up some pics, when I get finished.
I just found a used handheld cordless router on ebay!
And would this router bit be ok to cut the slots on the 9mm plywood?
Looking forward to getting started on this. I'll post up some pics, when I get finished.
And check that the ply is actually 9 mm thick.
Ahhh, I see. I'll need to read up - I see the one I have coming is a 1/4" chuck.
Yes, I take your point, thanks. In the short time I have been buying wood, I realise that the world of 'sizing' is not quite as straightforward as I imagined it would be!
Yep. Plywood thickness is a guessing game. I had a student several years ago make a chair from stacked layers of
3/4" Baltic Birch Plywood. We hadn't come across much metric material then and the student sliced his 3D model into 3/4" slabs that we cut out on our new (at that time) CNC. Of course all the BB was 18mm thick and when stacked together left his final prototype only 94.5ish% as thick front to back as he expected. The last semester I taught a student of mine wanted to apply oak veneer to both sides of BB plywood before we cut out her project parts. I needed to know the actual thickness to set up the toolpaths. She proudly informed me that it would be 19mm. Having learned this lesson several times before I took a micrometer to her panels and found the average thickness with veneer was closer to 17.5mm. So you can't rely on 18mm baltic birch to be 18mm thick. You likely can't rely on 9mm plywood to be 9mm thick consistently. If the plywood is close to 9mm, then cut a 9mm slot. You can sand the surface a little where the slots intersect if they seem too snug.
3/4" Baltic Birch Plywood. We hadn't come across much metric material then and the student sliced his 3D model into 3/4" slabs that we cut out on our new (at that time) CNC. Of course all the BB was 18mm thick and when stacked together left his final prototype only 94.5ish% as thick front to back as he expected. The last semester I taught a student of mine wanted to apply oak veneer to both sides of BB plywood before we cut out her project parts. I needed to know the actual thickness to set up the toolpaths. She proudly informed me that it would be 19mm. Having learned this lesson several times before I took a micrometer to her panels and found the average thickness with veneer was closer to 17.5mm. So you can't rely on 18mm baltic birch to be 18mm thick. You likely can't rely on 9mm plywood to be 9mm thick consistently. If the plywood is close to 9mm, then cut a 9mm slot. You can sand the surface a little where the slots intersect if they seem too snug.
Here in the colonies we can buy undersize router bits, that are supposed to be matched to the odd size plywood.
Original poster here , just wanted to update , that I eventually got this together and finished the shoe rack.
I put a back on it for stability and it's really firm now. It took me a while to figure out how to get the cuts to be spot on. I guess that there were easier/better ways than the one I went with - I used a 9mm straight cut router bit.
I then rubbed Danish oil over it which brought the colours out in it - But even after 2 days use, I realise it needs to have a 'hard' finish like a lacquer or something. (picture is from before I oiled it)
Thanks for all the help everyone. It doesn't look too impressive , but it's opened my mind up to what I might do next.
![Glasses Shoe Shelf Sunglasses Shelving]()
I put a back on it for stability and it's really firm now. It took me a while to figure out how to get the cuts to be spot on. I guess that there were easier/better ways than the one I went with - I used a 9mm straight cut router bit.
I then rubbed Danish oil over it which brought the colours out in it - But even after 2 days use, I realise it needs to have a 'hard' finish like a lacquer or something. (picture is from before I oiled it)
Thanks for all the help everyone. It doesn't look too impressive , but it's opened my mind up to what I might do next.
Update on this. My son asked me if I could make a DVD rack for him in the same plywood 'slot' system.
I used 12mm plywood and made a jig (see first pic) to cut half of the 170mm shelf width - it made life a whole lot easier.
I put a 12mm cutting bit in the router and off we went.
![Automotive tire Wood Road surface Grey Asphalt]()
![Wood Shelving Hardwood Rectangle Flooring]()
I used 12mm plywood and made a jig (see first pic) to cut half of the 170mm shelf width - it made life a whole lot easier.
I put a 12mm cutting bit in the router and off we went.
Looks great! Definitely nice when you can find a bit that matches the thickness of the material.
I'll add that for such a tall bookshelf you might want to add a bracket between top shelf and wall to prevent any chance of the shelf tipping forward.
4D
I'll add that for such a tall bookshelf you might want to add a bracket between top shelf and wall to prevent any chance of the shelf tipping forward.
4D
Simple jigs like that can make a huge difference.
Make it a little longer than necessary so you have some overhang and it will prevent the entry dings.
![Rectangle Wood Office supplies Line Font]()
Make it a little longer than necessary so you have some overhang and it will prevent the entry dings.
Thanks for 4d
That wasn't the final place for it, he put it inside a walk in cupboard, and he used a small bracket to attach to the back in there - thanks for tip though
Ah, that makes sense , yes. Great tip, thank you, I hadn't thought of that. And then I could mark the correct distance/depth on the jig with a marker pen to line it up.
On a related note, at the college I taught at we had a large CNC which students often used to cut out plywood parts. I came up with a CNC version of halving joints that would slide together easily but tighten up when finally closed. An example here: Tapered Halving Joint. This eliminated any frustration students had putting their crisscrossing parts together.
4D
4D
That is a very interesting 'twist' on the slot joint. Thanks for that 4D , I find the whole thing very interesting.
I was getting a bit fatigued after the 20th cut on that shelving job , what with the clamping, squaring up, and adjusting the router bit length etc. I have been aware of CNC machines for a while, and my mind turned to how easy it would be if I had one, although I doubt I could be patient enough to do all the computer stuff to set it up. I gave up on SketchUp as it was too much for me. And that is before we get to the price and the space needed , of which I have neither in abundance.
Thanks for help everyone! It won't be the last plywood thing I make with this 'system' of jointing, as I am looking at everything now and wondering if I could make it better/lighter/cheaper/more bespoke/more practical.
@4DThinker Do you think there is any way, by hand, to mimic that method you explain on the CNC on your blog?
And you mention in the comments section on the CNC forum via your blog "Most classic woodworking joints are not intended/design to be knock-down. I've been using the tapering of tenons, embedded square nuts, tapered dovetail slots, etc"
Do you have a link or know of a book that outlines these methods, as they appeal to me in terms of moving these items about and being mobile with them
A link or a book I've often searched for. The creative environment of a design college and teaching furniture design to creative students is what inspired my pursuit for original joinery solutions. I have my own shop full of tools including a couple small CNCs to experiment with. I often was challenged to solve the impossible and would come home to sleep on the challenge. Usually early the next morning I'd have an idea to test out before meeting my classes that day. I'd bring my sample solution(s) in to show the students. I retired at the end of the Spring semester last year and my blog has become my repository for the repeatable useful ideas. There might be a book in there among the posts. The solutions that were unique to a specific project left the building when the student graduated. My "Process" evolved from a natural engineering/architecture aptitude, mechanical drafting courses taken in high school, a couple of design degrees and 4 decades of that creative interaction with students and other faculty. Our Workshop 2 furniture class project was to design something that could be compressed down to 1/3 of its assembled volume for storage or shipping. The knock-down ideas came from teaching those classes. Using a CNC it easy to create a pocket to embed a square nut in. Machine screws/bolts are the best repeatable strategy for assembling furniture that you want to disassemble later. The better looking furniture connection bolts out there make this potentially an attractive detail.
4D
4D
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