Wooden Clock Kits

[HectorLooi]

Has anyone built a wooden kit clock?

If anyone thinks this is easy, think again. 

The kit comprise laser cut hardwood ply, solid spruce plates and carbon fibre rods for pivots. There is only one metal part in the entire clock, the pendulum adjustment screw. (Oh I forgot, the pivot are all fitted to ball bearings.)

The gears and pinions are all wooden. The laser cut leaves a resinous residue on the cut surface, which has to be sanded off. That's a lot of sanding. Every tooth, every hole, nook and cranny.

The gears look pretty precision cut.... until you mesh them together and everything binds. It took me half a day just to get the escape wheel and third wheel to spin freely. And that was using diamond files and tungsten carbide cutters in a micromotor. 

I can't wait to fit all the other gears. (Yeah, right!)

I set my deadline for Christmas day. At this rate, I'm not sure if I'll make it.

[oldhippy]

I have never been interested in these kits. For me its the real thing or nothing. You haven't said which Christmas day.   

[spectre6000]

I looked into them. The ones I kept finding only ran for a few hours at best. I'm certain that if one took into account the mechanical properties of various wood species, modern fabrication tooling/technique, etc. one could make a reasonably accurate wooden clock that keeps time as well as most decent mechanical clocks.

[dadistic]

American clocks with wooden movements were definitely a thing,  and they most certainly ran for more than a few hours.  Eli Terry made a *lot* of wooden movements. 

https://en.wikipedia.org/wiki/Eli_Terry

[spectre6000]

Oh, they're definitely a Thing. My first hobby was luthiery (made my first guitar from scratch at 16), and in addition to all things mechanical, the deeper end of woodworking has always had my attention. There are people that make wooden clocks all day long. The kits are the short run time I was referring to. My thoughts on wood species and techniques was thinking on the real wood clocks. They run just as long as a normal clock, but I haven't heard about any that were especially accurate over time due to wood's seasonal expansion/contraction. I have a massive spreadsheet that I've cultivated over the years of commercial wood species and their mechanical characteristics. It's geared toward luthiery, but a different read might yield some interesting species for various clock parts. Hardness, stability, oiliness, etc.

Problems with wood in clocks relative to brass and steel are that it's anisotropic (which can be thoroughly mitigated with careful assembly of plywoods; not the hardware store variety), soft (some species get pretty seriously hard), porous*, and every piece of wood has its own features that need to be worked with/around from a manufacturing perspective. It's the sort of thing that a clever artisan could do a lot with, but not really mass producable.

* Too long for a parenthetical aside. It doesn't handle oiling well because it soaks it up like a sponge rather than keeping it where you want it. There are ways to force resins into the structure so that this no longer occurs, without sacrificing too much of the wood's character. Additionally, there are species that are so oily as to have their own lubricity; kind of like oil impregnated bronze. 

[Marc]

1 hour ago, spectre6000 said:

I haven't heard about any that were especially accurate over time

Google John Harrison wooden clock. Nearly 300 years ago. Accurate to 1 second per month.

[JohnR725]

On 10/7/2023 at 8:40 AM, spectre6000 said:

I'm certain that if one took into account the mechanical properties of various wood species, modern fabrication tooling/technique, etc. one could make a reasonably accurate wooden clock that keeps time as well as most decent mechanical clocks.

As others have said wooden clocks that run have been made in the past. So yes if somebody was to grasp that they're trying to make a clock to run and keep time then with all the modern tools we have it shouldn't be an issue. But? Go back and look at the original kit that wasn't made as a running clock that was made as a novelty item resembling a clock that may or may not actually run. This is what happens when people have access to Lasers all sorts of strange and interesting mechanical things are made often times without thought as to how practical of a really are and how well do they really run at all.

 

1 hour ago, Marc said:

John Harrison wooden clock

In other words somebody who grasped the materials available and how to work with them and still make a precision clock. Maybe it would help if we had a video?

 

[dadistic]

If I remember correctly,  lignum vitae was often used.  I'm not sure about Terry's clocks, I should have the info here somewhere, just can't find it at the moment.

 

Ok, found it. Oak for the plates, cherry for the gears, and mountain laurel for the pinions.