Plywood clock

peasant wrote: »

Do you have access to a CNC machine or did you file all those teeth painstakingly by hand?

I cut them out using a scroll saw.





Fully built and running, before cleaning up, and painting the frame.


Here I have taken the clock apart after it was running a week with hands etc all fitted, to paint the frame and hands black. I left the gears bare.

Bullseye1 wrote: »

Amazing stuff. Do you sell your creations?

Not so far anyway. That`s the first attempt at a clock I made, based on partial plans I had from someone else`s design, with a few changes here and there. The mechanism is straight forward enough though, so designing from scratch would not be too difficult once there is an understanding of the gear ratios. There are gear design templates on the net, and then its just a matter of getting a ratio to drive the hour and minute hands from the great wheel (wheel driven by the weight), regulated by the escape wheel turning once every 60 seconds as governed by the pendulum length. The tricky part is getting the pallets to properly interact with the escape wheel, and also getting the front frame plate and back one lined up precisely enough so the gear arbours (axle`s) bearings are nice and free running.

Eoin wrote: »

You'll do well to find a strap that goes with it!

I know, and you would have to hold the wrist up at least enough to keep the 39 inch pendulum off the ground:)

Seriously though - brilliant work.

It turned out well at least.Its an unusual one to have up on the living room wall. I was surprised at how well it worked. When I first started it, I was confident I could get it working, but as it was near finished, and I was testing a gear at a time in the frame for smooth running, I was not quite as confident, especially when I started setting up the escapement. But it is running a month now, only stopping when I stopped it to dis- assemble and paint, and for a couple of pendulum length adjustments. It seems to run very reliably so far.

Wibbs wrote: »

I tried making one myself a few years back. My design was pretty funky if I do say so myself Even incorporated a grasshopper escapement. Suffice to say after a few sessions with a scroll saw I'm damn lucky to be still able to count to ten. :D So I'm full of admiration for your work robbie7730

The escapement is one of the hard parts to get working. A grasshopper one would be even more so. Did you get it completely built?

Wibbs wrote: »

I had it kinda working, though had to apply the force manually. I reckon it might have worked if I'd gotten the gears right.

Yea one of the main things to get right is the gears meshing without sticking. Adding in one gear at a time and getting them running smoothly before adding the next one is the way to do it. Frame bearing alignment from front to back is one that causes difficulty for many people making these wood clocks, and was the main one I had in mind while making this one. The further into the drive train the gear is from the drive weight, the less friction it takes to stop the clock.

If you were able to get a grasshopper escapement regulated mechanism working at all, then I think you must have been very close to having everything right.

Deep Thought wrote: »

Lovely Stuff

there is a website called woodenclocks.co.uk

The have a lot of plans etc

Yea i seen that site before alright. The basics of the gearing on most mechanical weight driven clocks is similar, but it does allow for a wide variation in design possibilities.

I was looking at videos of tower clocks in buildings, and the mechanism is practically the same as well, except with metal gears, and hundreds of pounds weight to drive them. Even the pendulum is the same length, although that can be changed by changing the gear ratio between the minute hand and the escape wheel during the design, if it was required to be a different length.

Wibbs wrote: »

That's bloody wonderful robbie7730. Thanks(again) for sharing. I'm looking at the numerals wheel and thinking "scrollsaw"? :eek:. After my last attempts my scrollsaw languishes in my shed on account of my phobia of seeing my own blood. BTW anyone want a scrollsaw? free to a good home.

Here is the numerals being cut out. It was easy enough, but time consuming because of all the internal cuts. Still needs a bit of cleaning up and sanding.


Frame with main gears. I just drew the frame direct onto the ply with a pencil and straight edge, and a curved edge I had from a different project I used for the top and bottom curves in the frame.

It still works anyway.

Live view of the clock for a few hours here.

The window bars can move it more central.

Made a couple more clocks since the last one on the thread, but last week decided to have a go at an Arnfield escapement, which is an interesting setup when seen in action. Just the minimum to get it going is done on it now, still needs sanding, hands, painting etc if I get round to it.

10 arms on the escape wheel rather than the 6 in the link above.

The video exagerated the sound level, but it still has a fair clatter out of it.

MiCr0 wrote: »

If you're ever looking to make some cash with these, make sure to let us know first☺

Ok, I was going to keep this one, but its requiring a new home now, with wall space disappearing.

Its running nearly a year now id say. PM or post if anyone is interested.
It would require an 8 lb or so weight to drive it.
(A second clock is ticking in the backround, its not a double tick-tock from this one)

Sorted there now.

Wibbs wrote: »

Can't wait to see the results of your labour B.

It's nothing too radical anyway. It was mainly to put one together that had main gears that each fit on an A4 sheet. All clocks before, except the very first one, the main gears require printing across 2 sheets.

I like the look of it though. I'll post photos later this evening.

Current project

Thirdfox wrote: »

Out of interest - how well are these clocks keeping time?

I would love something like this in my house

Time keeping would vary a little, according to conditions. I've had them within a minute a day.

Anywhere withing a few minutes a day is good enough though. The main point for myself at least, is the mechanics of them in motion.

Test of gears by manual turning of weight drive drum.

The exact ratio of it from weight drive wheel to escape wheel is 120.125:1
From centre wheel to escape wheel is 60.0265:1
This means the pendulum will be very slightly shorter than the 60:1 ratio clocks before this one. It wont be noticeably shorter, but just a fraction quicker swing needed.

Notice how the drum can be rotated in reverse freely, due to the ratchet and clicks setup, seen at about 22 seconds into clip. This is to facilitate winding.