Something completely different ( for me )

[Touchwood]

Hi All,

Haven't posted in a while because of health issues, that stopped me from doing my usual large projects (like rockers, display cabinets, big beds etc..). So I decided to build something small.

I've been intrigued by wooden gear clocks ..and decided to build one. Had to learn a bunch of new things for me (like using a scroll-saw, cutting accurate gears, getting the gears to mesh right..), and in this case, designing a precise pendulum drive system. That part put me back in touch with several old techi friends, which was a really good thing..great trip down memory lane. The result is a wooden gear clock with extreme accuracy.

The gear train design is from a clockster in Hawaii (that he used in his "Toucan" clock) but the rest of the design is mine (plus some teamwork on the drive)

Here's a pic of the clock, and there's a link below to a short video of the clock in action. I call it the Alpha Toucan because it's my first ever wooden gear clock, and the frame looks kinda like the Greek letter. That gives me the whole Greek alphabet to work through for frame designs, but I think Omega will be next .

Here's the link to the video ( I made a small math error at the start..it's actually accurate to about two seconds per year, and better than that in a normal household temperature range ).

http://touchwoodwoodworking.com/alphatoucan.html



Thanks for looking

Don

PS: Back to making big things again...but another clock is in the near future. Too much fun!!!:gar-La;

 

[Bryan S]

It looks great. :icon_thum

It might be a small piece but I am guessing it took a lot of work.

 

[Joe Scharle]

Looks great, Don!

I made one in the 70s (my alpha & omega), ran about a week and from then on was only accurate twice a day! :rotflm:

 

[Charlie]

Very nice. The video is great.

 

[Jeremy Scuteri]

Very cool project. I calculate 2ppm as about 63 seconds per year.

 

[Gotcha6]

Fascinating. Weighted or spring? Can't tell from the pic.....
OH.... Just watched the video....

 

[llucas]

Don, totally fascinating and mesmerizing....excellent craftsmanship and presentation. I really like the video with the music keeping time as well. Thanks for sharing.

 

[Touchwood]

Very cool project. I calculate 2ppm as about 63 seconds per year.

Hi Ron..you're absolutely correct for 2 ppm.

The spec. is actually +/- 2 ppm over the wide temp range, so I was taking the plus or minus, and figuring approximately a minute either way. The heartbeat of the drive is a DS32KHz from Maxim Semi.

http://www.maximintegrated.com/datasheet/index.mvp/id/2940

Anyhow, considering most wooden gear clocks use a weight or spring to drive the pendulum and need rewinding every week or so..it's not too bad

I was wondering as this got underway if I was building an electronic clock with wooden parts..or the other way around

 

[Canuck]

WOW!

What a work of art Don!:eusa_danc That video presentation is excellent as well.

The base that you made for the clock really compliments the clock.

Too bad it didn't make this calendar entry.

Wayne

 

[Jeremy Scuteri]

Hi Ron..you're absolutely correct for 2 ppm.

The spec. is actually +/- 2 ppm over the wide temp range, so I was taking the plus or minus, and figuring approximately a minute either way. The heartbeat of the drive is a DS32KHz from Maxim Semi.

http://www.maximintegrated.com/datasheet/index.mvp/id/2940

Anyhow, considering most wooden gear clocks use a weight or spring to drive the pendulum and need rewinding every week or so..it's not too bad

I was wondering as this got underway if I was building an electronic clock with wooden parts..or the other way around

What is actually quoted in the datasheet is the "frequency stability" over temperature. This is relative to the actual nominal frequency (32.768kHz). This is not the absolute accuracy, which will vary from quartz crystal to quartz crystal and will also depend on the battery voltage and load capacitance. You will notice that the datasheet does not provide Min/Max values for the output frequency, just a typical value of 32.768 kHz is provided. The absolute frequency will also change over time (aging of the crystal). It is not uncommon for quartz crystals to have an absolute accuracy variation in the neighborhood of 50ppm. All that being said, the project is awesome and nobody cares if it is off by a little bit over a year.

 

[Rick M]

Gear clocks are really cool.

 

[USMCSergeant]

That is amazing

 

[ScottM]

Welcome back Don. Glad you are feel well enough to get some shop time in. That is truly an amazing piece.

 

[Touchwood]

What is actually quoted in the datasheet is the "frequency stability" over temperature. This is relative to the actual nominal frequency (32.768kHz). This is not the absolute accuracy, which will vary from quartz crystal to quartz crystal and will also depend on the battery voltage and load capacitance. You will notice that the datasheet does not provide Min/Max values for the output frequency, just a typical value of 32.768 kHz is provided. The absolute frequency will also change over time (aging of the crystal). It is not uncommon for quartz crystals to have an absolute accuracy variation in the neighborhood of 50ppm. All that being said, the project is awesome and nobody cares if it is off by a little bit over a year.

Right on Jeremey, I had meant say a couple of minutes, not a couple of seconds

Actually there's not a separate quartz crystal..it's integrated right into the silicon chip, along with a bank of capacitors that are switched in or out to do the temperature compensation. The 32.768 is a binary number so I simply counted it down to 2Hz with a couple of decade counters to give me the two pulses per second I needed.

 

[merrill77]

Don, is it 120v or battery driven? If battery, how long do you expect the battery to last?

I think you need to bring it to the Triangle lunch bunch this Friday

 

[Mike Davis]

My wife got me a set of plans for a wood gear clock one Christmas. Still haven't started it. Did you use solid wood gears or laminate?
It really turned out nice. I have wanted to build one since I saw a friend's clock that his great uncle built. I saw it 30 years ago but it was already 50 years old then and still kept pretty close time.

 

[MagGeorge]

Totally cool clock! Like those functional gears and pendulum, made of wood and looks amazing. Excellent work!

 

[striker]

Very nice job. Always intrigued by wooden gear clocks.

 

[Touchwood]

Don, is it 120v or battery driven? If battery, how long do you expect the battery to last?

I think you need to bring it to the Triangle lunch bunch this Friday

Hi Chris...It's connected to a wall plug (not a wall-wart)...so ordinary line voltage. The coil driving the pendulum draws an average 80 milliamps from a 16 V. DC supply..so even a big battery wouldn't last too long.

I got thinking about the electronic drive for the clock when I found this baby.

http://macetech.com/store/index.php...s_id=8&zenid=ed4ffcedadba0bb854916b4c88358a0f

It does have a battery back up but only for time keeping purposes...they say it's good for 8 years, but not if you want drive anything from it. The chip on the circuit board is a DS3231, and it's clock is basically the DS32KHZ that I used ..both of which are much cheaper than the Chronodot.

The DS3231 counts and outputs Seconds, Minutes, Hours, Day,Date,Month and year with leap year compensation valid up to 2100 AD...pretty excessive for a wooden gear clock ( but I have one driving an LCD in the shop anyway. )

Thanks for the invite to the Friday Lunch Bunch..I'll try to make it.

Don

Don

 

[MrAudio815]

Don,


That is simply Beautiful & so useful~! I bet you are going to have a ton of people watch that awesome video too.


Very nice indeed~!