If you missed part 2 please find it here.
Finishing the frame and mounting the gears
The frame is finished with spacers on the backside and holes for the axles. The spacers on the backside are designed to create a space for the pendulum between the frame and the wall.
The frame with gears
In the last photo all the gears are mounted in the frame as a test to see if they will actually work together. I assembled the rest (pendulum and all) and started testing how much weight it takes to run the clock. Brian Law suggests starting with 6 pounds but I chose to start considerably lower with 1 kilo.
Here my first serious setback happened in the project. There is a piece in the shape of a semicircle (number 31 in the plans) that allows the clock to be winded and prevents the spool holding the weight from running backwards. It broke and the weight fell on the floor with a bang! It was simply to tiny to hold the weight.
After a few “blessings” I started all over again with a new spool (number 34 on the plans) and two new gears (numbers 30 and 36 on the plans). I chose to make the spool diameter larger (about 1.5 times the original) and to create a gear with larger teeth than the original (number 36 in the plans). Of course I had to create a new version of number 31 on the plans that will fit my new gear (number 36) and be stronger than the original.
I then reassembled the clock for another test and it actually works. 🙂
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.