Wooden Clock

Introduction

Should anyone else be interested in making one of these wooden clocks then here are some more details of the version of wooden clock I made. I would recommend anyone interested in clock making just to have a go at making one yourself. You learn and appreciate a lot more about clocks by making one yourself, compared to reading 100's of books. Well that's my experience anyway.

It really is a lot easier than you can imagine and really great fun. The best part is when you see the construction actually start ticking! If the only think that's stopping you is the idea of making gears yourself then just download the DXF drawings and get them made at your local CNC shop....or for a fee I could cut a complete gear-set for you.. :-). Just fill in this form to register your interest. Note there are many people who have successfully made wooden gears using bandsaws.

The original designs were kindly made available to the public domain by Gary Mahony , who's website was down for a long time but I noticed it is now up and running again. The plans for this particular clock, which I believe is called 'Clock 2003', can be downloaded from his website here . (I have problems with the links, but can also be downloaded from ldrider website here )

I've made some modifications to the design according due to the following reasons:

    • I've converted all dimensions from inches to mm

    • I used much thicker 8mm plywood. I just had a better feeling that thicker ply would allow more more tolerance for lining up the gears and for spread the load and wear better. The ply used for this prototype / proof of concept, was the cheapest softwood ply that I could find from the local DIY shop. It only has about 3-4 layers, compared to the boat builders or aircraft quality ply which has about 7-8 layers and made from hardwood. The main objective was to test the design and CNC cutting using cheaper wood first. Once I got that working I would feel more comfortable to invest in hardwood ply. The back and front of the clock is made from 18mm cheap pine wood, which can be bought from any DIY shop or sawmill, normally used for making shelves.

    • I've made brass/bronze bushes rather than plastic bushes

    • I mounted the pendulum to the front of the clock a) for easy removal and adjustment of clock b) to see the pendulum features clearly

    • I've added pendulum cock, pendulum crutch and a pendulum leader to the swinging mechanisms as part of this redesign. The redesign details have been included in the CNC files on the download page

All my own designs have been added to the download page according to the Creative Common Licence Attribution-ShareAlike so others can freely use, improve and republish too.

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    • I have also included all my CNC Gcode files (note that these are also in mm's) and are assuming you are using a 2mm milling cutter. This should save you all the trouble of converting them yourself, but please simulate these files on appropriate CAM software (e.g. LazyCam) yourself before machining. The stock material was 8 mm ply so take care when cutting your depth. The Gcode files can easily be edited with LazyCam or Mach3 to decrease or increase the cutting depth as required. The files and designs are available as-is i.e. with warts and all. I will be updating these as soon as I have some time to start working on this project again, so make sure subscribe to the download page to be informed of any changes.

assembled clock

wooden ratchet for winding mechanism

Front plate lifted to show steel pins in the wood arbour. Gears are shown straight from the CNC without any sanding

Wooden Arbours

All arbours needed to be align up together so non of the wooden dowels touched either the front or back plates. I setted for 1mm -2mm end-shake on each gear which seems to do the trick.

Colin's Clocks Download Page

Note: You can edit DXF and Autocad files using the free CAD software called Draftsight from Desault System who also develop Catia and other professional software

Pendulum Redesign

As I perceive this clock more as a kintic sculpture than a time piece, I want to have all main moving parts to be clearly visible at the front. I also wanted to be able to easily adjust the pendulum and , when necessary, to quickly remove the pendulum without having to dismantle the entire clock. The final longer looking pendulum makes the clock also look much bigger.

I originally made the brass bushes as a slide fit onto the pivots which ended up far too tight. These bushes needed to be broached to the correct size. As I don't have any broaches so using the same size drill in my hand I just lightly wiggled around. It seems that some small amount of 'slop' is required to ensure correct alignment of the gears and to give some room for the wood to move. The small amount of 'slop' doesn't seem to affect the timing of the clock and makes the gears whiz round freely. All gears were tested for binding by just blowing onto the gears to see if it whizzes around. Each set of gears was then assembled and 'blown' to see if the freely rotate. The smaller escape wheel is the critical check and ensure it obtains constant pressure throughout the drive chain. It took quite some small adjustments to get this running freely. I think I must have taken all gears in-and-out over 100 times and could now probably assemble the clock blind folded. It was useful having a good tight fitting dowels that hold the front and backplate together as I didn't need to screw the assembly apart each time. The pressure from the dials held everything together. I only fitted the retaining bolts after the clock had been working for over a week.

Brass Bushes & Pivots

I made silver steel pivots that were push fitted into the wooden arbour shafts. The pivots were polished on the lathe to remove any burrs. The arbour shafts were standard dowels bought from the local DIY and are probably made from mahogany.

Gears

All gears were made on the CNC machine. The CNC files are included on my download page. I sanded down all spokes to give a smoother appearance and also the gear tooth edges. I did not sand the main gear face though, unless I could see that it was binding somewhere. Gears were 'push fitted' onto the arbours.

I think it was a great ideas to use cheaper wood. Mainly because I tended to make much bolder decision regarding alterations as I new it would be easy to just to remake a another gear on the CNC if the idea did not work.

Results

I've learnt and appreciated much more about clock design by building this clock then all the years I spent repairing and reading up about clocks. The approach is really a great learning process to gain a deeper understanding of how clocks work and what are the really important aspect of the design to get a clock to tick properly.

I think it was a great learning exercise also to modify the design and try something different new. I'm actually very surprised that the clock ticks at all! I'm particular surprised on how well the plywood machines; i.e. very clean edges without too much sanding required. The bright 'white' finish of the cheap plywood and pine looks much better than I thought. I'm also surprised that the gears fit together really well with very little sanding required to get the gears to rotated freely. After machining the gears and wooden back/front plates I left the parts in my workshop for about 12 months before I had again time to get back to this project. I was really surprised the the wooden gears hadn't warped or moved out of shape over that period one little bit. This gave some some confidence to continue with this project, however I don't recommend leaving a project that long as it took almost a complete day to remind myself why I made certain decisions the way I did. I made all gears 'push fit' onto the arbours so I had a chance to adjust the alignment of all gears later and if necessary can easily exchange any gears that get damaged. I only glued the main gear wheel as the weights started slipping.

Other comments

Really has been an exciting project. MKII is already on the drawing board and now with much greater confidence I will it from hardwood ply. The only additional redesign so far is to make the backplate bigger - so the weight wheels also have a background. Use darker wood or paint the background to give better contrast to the gears. As we have white walls in our house the white clock' tends to disappear

The main modification were made to the position of the pendulum, which required the pallet arbour to be extended though the front bush and a crutch mechanism added (the design in the DXF files). I also needed to hang the pendulum just under the minute wheel. A brass 'stud' was made for the pendulum to hang on and a sleeve over it with a slot filed in it for the pendulum to rest in. A pendulum leader was also specially made to give clearance around the pendulum crutch and a method of fine tuning the position of the escapement pallets. I'd seen the design on other clocks so was fairly confident this arrangement would work. The first design of the pendulum crutch was made our of piano wire and bent to the required shape. This tending to flex too much, which made the ticking irregular. I therefore made one of plywood which gave the necessary rigidity to the escapement mechanism and worked really well.