If you missed part 1 please find it here.
My box joint jig prototype
As mentioned in part one I’ve decided to make an Arduino driven box joint jig for my table saw and as part of that I mentioned that I’ve made a prototype box joint jig. I this post I’ll show you some photos of my prototype and my first box joint made using the jig. 🙂
First things first: Here are some photos of my prototype:
Box joint jig prototype
Box joint jig prototype closeup
Basically it’s just two boxes of different sizes – on inside the other. The inner box is mounted on two drawer sliders and is moved back and forth by a 8 millimeter treaded rod with a handle. The treaded rod is mounted using two ball bearings (ball bearings for roller blades fits perfectly) and a homemade handle is mounted on one end. One turn of the handle will move the inner box 1.25 millimeters (which is the lead of the rod).
On the bottom of the outer box I’ve mounted two pieces of wood that fits into the grooves on the table saw to keep everything aligned.
Even if it’s a rather crude prototype it makes box joints rather nicely:
Box joint made with the prototype
In time, when my Arduino project is finished, the stepper motor will of course replace the handle and the electronics be mounted in a box but as a proof of concept I don’t think it’s that bad. 🙂
I’m still debating with myself weather it should be a jig for the table saw or a jig for my router table since my table saw isn’t that good. Both ideas have good and bad sides…
I’m a big fan of the magazine Scroll saw woodworking & crafts and I read it with interest every time. Especially the many patterns included in the magazine makes it a useful resource. Here I found a fretwork trivet pattern in Scroll Saw Woodworking & Crafts Spring 2013 (Issue 50) and made it on my scroll saw.
It’s made from plain pine wood – nothing exotic about it. Here are some photos:
Fretwork trivet 2
My first real Arduino project
Let me introduce my latest project: An Arduino driven box joint jig for my table saw! I saw a video on YouTube where some guy showed a box joint jig driven by a stepper motor and I decided to make one myself.
I already build a hand driven box joint jig very much like this one made by Matthias Wandel (it works fine by the way), so I started to build the electronics using an Arduino One, a 16×2 LCD screen, a Pololu A4988 stepper motor driver shield, a rotary encoder (with a micro switch included), a 18.5 V power supply, a Nema 8 stepper motor (SY20STH30-0604A) and some smaller parts (resistors, an LED, a LM7805 regulator and a capacitor). The whole thing looks like this:
Electronics for my box jointer project
Here is the schematics for it (without the LM7805 regulator and the capacitor):
Schematics for my box jointer project
The rotary encoder is used for controlling the menu (the switch labeled S1 on the schematics is actually built in the rotary encoder). The switches S2 and S3 are used for resetting the jig and for moving the stepper motor forward.
Here’s the sketch (it may be subject to change or include bugs): BoxJoin
If you missed part 1 please find it here.
For the frame of the clock I decided to use a dark hardwood so it would be a contrast to the gears made from birch plywood. I decided to use Itaube, an oil rich type of hardwood from Brazil with a nice reddish brown (sometimes almost orange) color. Most of all I chose that kind of wood because it was the nicest dark wood my local timber yard had in store. 🙂
In Denmark Itaube is mostly used for making terraces because of its durability so the board I bought at the timber yard had grooves on one side (which didn’t suit my purpose very well). What to do? I went to our local carpenter who was kind enough to run it through his planer for me to get rid of the grooves. The board was now just 16 millimeters thick but much nicer than I could have made it myself using a hand held planer. The funny thing is: When you sand Itaube it turns a kind of gray but after a couple of days the reddish brown color comes back (I don’t know why but I guess it has something to do with the oil content).
The backside of the frame looks like an inverted cross with cutouts on both the vertical and horizontal board so the assembled frame has the same thickness as the individual board (that kind of joins probably have a name which I’m not aware of). I made the cutouts using my router table and a hand saw (see photo number 2). On the last photo all the pieces are ready for assembly. I chose to use both dowels and glue for assembling the frame to make it stronger.
Holes for the axles and a first test
The first photo shows the finished frame (assembled but not glued) and all the gears. I chose to drill all the holes in the front and the back at the same time – and one pair at a time! Since my gears are handmade inaccuracies can’t be avoided, so I drilled one pair of holes and used the gears to find the placement of the next pair of holes (see photo number 2).
Why a wooden clock?
Well, that’s quite easy to answer: I was just curious to see if I was able to do it! At some point I stumbled across Brian Law’s homepage with drawings of wooden clocks and I couldn’t resist. So I decided to try to build clock number one from his homepage.
I was well aware that I might be forced to change the design as I went along but I was convinced that I would learn a lot in the process – and I did.
After having downloaded the drawings from Brian Laws homepage and printed them as A3, I decided to start by making some of the gears – as a proof of concept. After searching the Internet for ideas I decided to use my scroll saw to make the gears (I found a lot of other methods out there: band saw, table saw, router and even laser!). As seen in the photos I didn’t shape the tip of the teeth in the first place and concentrated on making the sides nice and even
After some experiments I found an easy way to make sure that the gears were a nice circle: I drilled a 1.5 mm hole in the center of the gear and attached it to the scroll saw as shown in the photo. Then I turned the gear sawing off the tip of the teeth one at the time thereby making my hole the center of the gear. This method worked nicely.