Dave,
You are correct the extra 1 is a typo so you can ignore. 12.5mm will be fine you will of course need to reduce the length of the spacers accordingly and increase the length of the main shaft by 5mm.
You are also right about the 11 wraps around the drum, however this is a function of how high you hang your clock, the top of mine in around 2.1m (7') off the ground and the weight runs out of room at around the 11 hour mark. I had thought of doubling the length of cord and using a pully on the weight, however this would mean doubling the weight which would place too much load on the wooden bearings.
If you would like I can provide pictures of all the assembled gears which might help.
Tony
No, the weight the wooden bearings saw would be the same. Each end of the cord would see 1/2 of the larger weight, so the pulley would see the normal amount as it would only support one end of the cord. One cord supports five pounds A cord anchored at both ends with a ten pound weight in the center would still only see five pounds at the ends.
In that case I stand corrected and suggest that may be an option to increase the run time to a little short of 24 hours
I wonder if in addition you could increase the size of the drum to say 80mm or larger and get even longer run times... it seems there is enough space...
Bob
Mr Wild, Good catch on the equal string loads.
Bob, Increasing the drum size would reduce the run time, as the 7 foot of cord would have fewer wraps.
So it follows that a decreased drum size would provide more wraps with the limited 7 foot of cord.
Yet, a smaller drum would reduce the applied torque, so an appropriately greater mass would be needed.
Yes I understand it would have fewer wraps with a 7 foot cord on a larger drum.... but Tony suggested making the cord longer using pulleys to take up the distance issue. my suggestion was a sort of gearing ratio to allow less cord travel per swing of the pendulum
Blackbeard,
I think you still have it backwards. A larger drum would require more rope to achieve 11 hours (11 wraps). I think a smaller drum would give more wraps for the same 7 feet. More wraps equals more hours.
I ordered my rods and sleeves from this company.
http://www.onlinemetals.com/
1 piece @ $12.48/piece
Stainless T-304
Seamless Tube
0.3125" x 0.028" x 0.2565"
Cut to: 36"
-------------------------------------------------
1 piece @ $3.03/piece
Stainless T-304
Round
0.25"
Cut to: 36"
So I'm committed to a larger hole in each of the gears.
I found a Google Sketchup 3D model of the Law's Clock1. Google is really an awesome company. Anyway, those of you who are interested, you really must load the free Sketcup CAD program from Google. Then go here and find the clock1 model.
http://sketchup.google.com/3dwarehou...61&prevstart=0
I've been cutting lots of gears, frames, and other stuff too. 95% of it is cut using VcarvePro, the other 5% is lathe work.
What kind of wood are you using for the gears? MDF or Plywood? Looks good
jgro
JGRO,
I am using 1/2 Birch Ply. I'm not particularly impressed with this wood, but it's ok. The plans call for 10mm (aka 3/8", but I couldn't find any of that). The frame is a clear ???? from Home Depot. I forgot it's name.
I have posted them on my web page where I am building the clock out of brass & aluminum. Gary gave them away for free so I thought that since they didn't seem to be available anywhere else, I'd post them here.Originally Posted by emtffkev
http://www.ldrider.ca/cnc/garysclock/garysclock.htm
David
I don't care for the 1/2" or 3/4" birch from Home Depot, but like the 5mm stuff. There are 3 inner layers with very thin birch on the outside. I have cut around 10 sample clock gears and have only seen 1 or 2 small voids. The teeth seem to chip a lot less than true Baltic birch.
I use a single layer for the wheels and glue 2 thicknesses together for the pinions. This brings the thickness close to 3/8".
The cost is reasonable also. Around $24 for a 4x8 sheet as I recall.
Steve
David M,
That's pretty impressive. Your website is great. There are lots of folks talking about where Gary's website went. Glad to see the info post on your site.
Steve, The info about plywood in appreciated.
what kinds of gear is this Wooden Clock Gears??this is an unique gears!
___________________
Great thing to know about busby seo test.
Back in January 1986 Fine Wood Working magazine published plans to build a wooden clock. I bought the magazine and have been scratching my head ever since. Yes 23 years. I stumbled upon this post about a year or so ago, and re-kindled my desire to try this. I think this winter is finally going to be the time. After studying the article several times, and reading all the links and posts here, I think I have the gears down. What I still can't grasp is how to make (and what to make them from) the bearings (sleeves?) and arbors. From my reading I am thinking of using Brass sleeves and steel rods. But I am not sure how to do it or how to connect them all together. Any and all guidance would be appreciated. Pictures if possible, as if I can see it, I can usually figure it out.
Thanks in advance.
You may want to read through the Beal Tool clock forum threads on bearings.
http://www.bealltool.com/clockforum/index.php?board=8.0
I am also on a quest to make a wooden clock. I purchased the back issue of the article. There are also many good plans available on the internet. My goal has morphed into designing the clock in addition to building it. This has pushed out the finish line by a considerable amount. I would say that I am about 50% finished after about 5 years of planning.
Plan on everything taking around 10X longer than your initial estimate.
There is a good discussion of ball bearings for clocks at http://groups.yahoo.com/group/mlhorology/files/
best of luck
Steve
It is good to see, someone else takes forever to complete a project. I have also decided not to go the kit route. In my own mind it seems to be cheating. I have thought about buying one of the hardware kits out there so I could see how they do the bearings and rods. I still might if I can't get a better understanding of how this is done. Not sure why I have brain block on this, but I just can't seem to figure out how to make this work. I'm sure it's simple and will wake me up in the middle of the night at some point.
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