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Pomare
21st December 2007, 05:23 PM
Hi there,
Been making these wooden movement clocks for a while now.
This one is from NZ native timber "Tawa" and African Rosewood. They keep
relatively good time when properly adjusted within about 1-2 minutes a day and run for 48 hours per wind. Sorry photos are not the best.

Simomatra
21st December 2007, 05:44 PM
They look fantastic from here

Well crafted

BTW welcome to the forum

lukewarm
21st December 2007, 06:14 PM
They're awesome.

I've been interested in these of late, where do you get plans for the movement?

cheers,

Luke

charlsie
21st December 2007, 06:29 PM
absolutely fantastic but you have to tll us how long would something like this take to make and how do you cut the gears?

ravlord13
21st December 2007, 06:54 PM
Nice Stuff,
Again all the above Questions ,
Would like to have a go at one but doubt I have the patience :2tsup:

Hobbyhorse
21st December 2007, 07:27 PM
Pomare,
Congratulations on a fine job. Did you use an existing plan or design your own movement?

Rhys H:)

Pomare
21st December 2007, 09:38 PM
Thanks for your comments
I will try to answer your questions.
The original clock was designed in America and plans are avail in
the Fine woodworking Series - "Small Projects" book. However I have extensively modified the original both in it's design and entire construction.
All the shafts in mine are from brass encased in wood to ensure that they
run true. Pivots are from HSS drill blanks running in brass bushes in the plates. The main drive shaft runs in a needle bearing in the front and a HSS pivot at the rear. I have used pulleys to double the run time however this of course, using the same size weights, means that friction becomes double the problem as the weights have effectively been halved.
All the gears are cut as a stack usually about 6 at a time mounted on a mandrel in a dividing head on my small Emco FB2 mill using a single point fly cutter and all the turning is done on a Myford Super 7. It would be possible to cut the gears by hand but it could be fairly laborious.
The original design had laminated gears ie. about 3 laminations however gears made this way have a tendency to warp badly. I have found a far better way to make both the plates and gear blanks is to glue them up using 30 deg segments each cut down the grain. You can see this on the front plates in the photo ( the joints are behind the inset hour strips). Evidently when they x rayed the gears in one of John Harrison's clocks from the 17th century they found he had segmented his gears but hidden this behind a veneer on the front and back of each plate so obviously way back then he had the same problem with warping!!
I use a mixture of 1 part each turps, tung oil and satin polyurethane as a finish.
I'm happy to try to answer any more questions
John (Pomare is my street name)

Hobbyhorse
23rd December 2007, 10:30 AM
John,
Thanks for that. I had wondered whether it was a Westphalia clock from Fine Woodworking. Your experiencs with the warping is interesting. I used oak and self made plywood with epoxy glue for the movement that I built and thus far it has stayed straight...maybe time will prove otherwise.
I have the plans for the Clayton Boyer clock "Inclination" for next years winter project but am at the moment tinkering with a verge and foliot movement which is very basic and more of a learning experience. If I get it to work I will put up some pictures.

A good christmas to you.

Rhys