My Clock Build Project Thread

I don't have any thoughts on what the thickness ought to be, but I think the only time I've ever seen wheels as thick as 1/4" was on a tower clock. Those might have been cast iron, however. :D

Pinions are usually cut from pinion stock and are much longer than they need to be just to allow wheels to find their own alignment. That simplifies construction quite a bit, because the shoulders on arbor pins don't have to be so precise.

Next time I'm in the shop (this weekend), I'll look to see how thick are the wheels on the tall-case movement I'm working on at present. I'm thinking maybe 2mm, but that's guessing.

Rick "except for barrel-wheel threads, which carry more load on each tooth and are maybe twice as thick as wheels in the going train" Denney
 
I didn't mention that this will be a skeleton clock with an exposed gear train. I got some advice from a clock/watch forum that the wheels should be at least 3/16" thick or more for such a clock. Hence, I decided on 1/4" wheels and 3/8" pinions.
 
I'm starting to think about hardening the pinions and escapement pallets. It's a ways off, but I'm thinking ahead. The pallet is 4140 steel and the arbors are W1 drill rod.

My first thoughts were propane or MAP torch, but now I'm not so sure. I've never hardened anything. I've been looking at the Hot Shot 360 oven series which seem to be highly regarded and not overly priced. I'm thinking these are much more precise that a torch.

Thoughts?
 
devils4ever said:
I'm starting to think about hardening the pinions and escapement pallets. It's a ways off, but I'm thinking ahead. The pallet is 4140 steel and the arbors are W1 drill rod.

My first thoughts were propane or MAP torch, but now I'm not so sure. I've never hardened anything. I've been looking at the Hot Shot 360 oven series which seem to be highly regarded and not overly priced. I'm thinking these are much more precise that a torch.

Thoughts?
Click to expand...

The pallets, absolutely. One that sort of deadbeat design, the pallet fork is often through-hardened and file-hard. Adjust it first but you’ll still need to touch it up after hardening, but you’ll use stones for that.

Pinions I’m not as sure about. I don’t think it would do any harm, especially if hardened to blue them, which would look nice given they will be exposed. Lots of old clocks used lantern pinions with pins from hard steel but not file-hard by any means. Bluing is done by placing the part on a copper plate and heating the plate from underneath until you see the right color, etc. Small parts don’t need the volume of heat provided by MAPP, I wouldn’t think, but that’s not experience talking.

You can make arbors from blued steel, too. I’ve bought arbor stock already blued for some projects.

Rick “encouraged to get back on current clock project” Denney
 
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Made some more progress on this project. Cut two 96T gears for the Great wheel and Center Wheel.

Unfortunately, I made a few mistakes along the way. Hopefully, this will help others not make the same mistakes.

Don't move the dividing head until the cutter completely clears the gear blank! I got a few teeth that got slightly deformed this way. It was probably okay except for the fact I messed up even worse by not moving the dividing head the correct amount on my second pass which made the gear blank worthless for this size gear. I can use this stock for the smaller gear fortunately.

Morale of the story is cut your biggest gear first so they can be used for smaller ones if you mess up like I did!

Gear blank getting cut to size on lathe.
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Blank cut to size.
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Ready to cut some teeth.
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First few teeth being cut.
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First pass complete (before screw up on next pass).
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New gear blanks cut in one pass and without screwups. Note dividing head using custom plate with 24 holes and the numbering on it to help prevent errors.
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Completed with gage pins used to determine if depth of cut was right. Turns out the distance over the pins were only off by about 0.002". I'll claim victory! Note scribed lines going across blank to help make sure pins are in the correct place. Live and learn. It's very hard to determine if the pins are in the right locations with a 96 tooth gear mounted on the dividing head.
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Just finished up the cutting of the teeth on the 90 tooth gear (wheel). Nailed the distance over the pins within 0.001".

I'm glad the high tooth count gears are done. It does take a bit of time to cut 90 or 96 teeth!

90T gear done!
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90T gear mated with a pinion on my depthing gauge. Seems to have a nice smooth action.
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I needed to remake the escape wheel in brass since I made it in aluminum as a prototype. I also reduced the thickness from 1/4" to 1/8" based on some feedback that the escape wheel needs to be as light as possible. So here it is.

Blank clamped to the rotary table after being turned to size on the lathe.
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First pass done with a 1/4" end mill to remove the bulk of the material.
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Second pass done with a 1/8" end mill to complete the "teeth".
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Time to cut the spokes. First pass with 1/4" end mill.
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Clamping the workpiece is always a challenge. Spokes done.
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Time to tap 2-56 threads using my homemade (Joe Pi design) mini tap handle.
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Done.
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Mounted on arbor with hub.
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Looks great, but I am amazed by the way your material changes from brass to aluminum and then back to brass! I have never got that trick to work?:rolleyes:
 
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