This project is a quick and dirty version of Izzy Swan's amazing table saw for kids. I can take no credit for the idea. That guy is a genius. But it's an easy build and safe to use. I made two of them for our STEAMlab and they are used every day by students from kindergarten to grade 6. They love it and it teaches them a lot of useful skills about working with tools and enabling them to make some pretty cool stuff. If you find this project useful, you might want to drop by Izzy's Facebook page and give him a 'thank you'.
Let's get started...
Step 1: Materials
This contraption is built around a device called a nibbler, which is a tool made for cutting sheet metal. If you look at the close-up image, you can see there is a slot where the material slides in and a post that moves up and down. The little tooth on that post bites into the material to make the cut. This nibbler fits on the end of a drill that powers it. It goes up and down and you push the material through. The kerf (width of the cut) is about 6mm. There are also pneumatic and electric nibblers. The one I used is the same one that Izzy uses in his video. It is made by Uxcell and is available on Amazon.
Aside from the nibbler, you will need a drill. I bought cheap, Chinese-made ones that work fine although in retrospect I should have gotten keyed ones instead of keyless. After extended use, they sometimes need to be tightened.
Like many of the other tools that I have built for our makerspace, this is made to fit on a Black & Decker Workmate. This works well for us because the Workmates are sturdy but the legs can be folded in so they sit lower to the ground for the younger kids to be able to use them.
For the rest, I built it mostly out of scrap wood and used hooks, zip ties and some bits of shelf liner to hold the drill in place.
Step 2: The Bottom of the Top
I cut a rectangular piece of 1/2" plywood to fit on top of the workbench. I marked the center and used a spade bit to drill out a hole for the nibbler to fit into. Then I used a jigsaw to open up the hole into a bit of a keyhole shape. The reason for this is to allow for waste material to be expelled from the nibbler. In the close-up image you can see where the hole is for the waste material to come out.
Step 3: The Top of the Top
I cut another rectangular piece of 1/2" plywood to go on top of the last one. Then, I cut it into 5 pieces. I wanted to have slots for a sliding miter gauge. The two thin pieces in the picture will be slid in and out. It makes for a bit more work and to be honest, we don't really use it much so far, but it looks cool and may turn out to be useful in the future.
I marked and drilled out the center with a smaller hole this time to provide a nice friction fit for the end of the nibbler. To make sure I drilled the hole straight, I used my drill press to drill a hole in a scrap piece of wood using the same drill bit. Then I used that scrap as a guide when I drilled into my top.
The next step was to chisel out a bit of material to make sure the opening where the waste material would be expelled was clear.
Step 4: Glue and Clamps
I glued the pieces and put them in place, using an extra board to hold everything flat. Then I slipped the thinner pieces out (so the glue squeeze-out wouldn't stick them in place) and clamped the pieces.
To reinforce the wood around the hole on the top, I masked off a little square around the hole and applied a thin layer of epoxy.
Step 5: Putting the Nibbler in Place.
When everything was dry, I put the nibbler in place, making sure that I had nice clearance at the top. Since the gap where you insert the material is only about 3mm, it's important to get it seated properly so the bottom edge of the opening for the cutter is flush with the tabletop. If it sits too high, your material will bump into the nibbler and won't slide smoothly into the cutter. If it sits too low, you have even less than that 3mm to work with.
I cut a trapezoidal shape out of scrap and used a hole saw to cut a hole to hold the nibbler properly in place. I ran it through the table saw a few times, taking off a mm or so with each pass until I had the thickness right. Then I cut a bit out on one side to make it into a sort of clamp to hold the nibbler firmly in place.
A new trick I learned recently is to use a dab of hot glue to hold things in place while you drill and screw. That's what I did here and I got a nice tight fit.
Step 6: Adding the Drill
I cut a bunch of random triangular wedges out of wood in various sizes. Then, after I put the drill onto the nibbler and tightened it up, I slid them underneath until it was sitting nicely in place. Notice I put some little scraps of shelf liner on each one just to help prevent it from moving around and hopefully to cut down on vibrations. Finally, I screwed some hooks into place (4 of them) and used zip ties to hold the drill on.
The Workmate has two boards on top. One moves back and forth when you turn the cranks and the other one you fix in place so it works as a vice. That board can be removed and I took it off to fit this on.
I added a strip of wood that would sit up against the tabletop piece on the Workmate to keep it from sliding around. Then I put a couple of blocks in the lower corners to sit on the metal frame. The space between the metal frame and the worktop of the Workmate is the same thickness as a 2x4 so it's pretty easy to make things to fit on there. (In this case, I stuck a couple of 1x4's together...)
Finally, to make the miter gauge, I just traced a protractor onto a piece of MDF, then cut it out and glued the protractor onto it. I put a nail through the origin to attach it to one of the sliding pieces. When I get some wing nuts, I will put a screw in to hold it in place.
Step 7: All Done!
To start your machine, pull the trigger on the drill and press the button to lock it. (In my case, I connected it to an extension cord that has its own on/off switch. That's how we turn ours on and off.)
Since it was designed to cut through sheet metal, it cuts through cardboard, plastic and thin wood easily--pretty much anything that is less than 3mm thick. Since that gap is so small, it would be very difficult to get hurt using this machine. That being said, nothing is impossible. Please exercise caution. Children should only be allowed to use this machine under adult supervision. And be sure to check it over to make sure everything is in working condition before allowing children to use it.