Making thin section clock or barometer hands ?

This might be one for the clockmakers amongst you - What techniques are used to cut and finish the thin tapering hands or pointers you see on clocks or
barometers ? Forming the larger section of, say, a barometer pointer wouldn't be too hard but to get that long tapered end seems rather difficult. My guess is that it might be clamped between two much thicker pieces of scrap to provide support while filing it down. Any suggestions ?
Dean
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Dean wrote:

I'm no clock maker, but I would use electro chemical machining. It works great for thin sections.
MA
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"Mustafa Al-Shawaf"

That's a good suggestion, but I'm since I dont have an electro-chemical setup I was wondering what manual techniques are used. I have seen instruments made 150 years ago with such parts and eletro-chemical methodes were probably not widely available.
Although...its amazing what was around years befor you'd think. I just read last night that the first experimental stereo recordings were done in the late 19th century !
Dean.
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Dean wrote:

If I was doing this in a factory setting with that technology, I'd glue together a stack of thin metal and file them down.
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wrote:

Greetings Dean, I'm no clockmaker either. But I have sawn parts that were similar to the clock hands. The method I used was to back up the piece with a piece of wood and then use a jeweler's saw to cut out the piece. If you cut the piece out of a sheet it is easier. A jeweler's saw has very fine teeth and cuts on the down stroke. So, lay out the part on a piece of sheet and clamp a piece of wood in a vise where you can sit at and work. The part of the wood that protrudes shouldn't be too thick because you will need to make a saw cut through it at least 1/4 inch long. After making this cut lay the sheet on the wood and cut. Just move the sheet as the cut progresses. You can also cut a deep vee into the wood and use the edge of this vee to support the work but that is harder and since you are just doing this for the first time try the sawed slot. Cheers, Eric R Snow
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My SB9" came with a 1/3 hp motor and it will make the flat belts slip. If you keep the flat belts, you can probably go to 5+ hp and not worry about adversly effecting the gears ;^)
Jake in Escondido
Mustafa Al-Shawaf wrote:

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I used to make watch and clock hands to repair antique clocks and watches. Grooves of suitable thickness were cut in hardwood blocks. These would support the thin sections as I filed them. Clock spring was used for pocket watch hands. After making the hole, and forming the boss (hour hands), the blank was hardened, and tempered. Then file it to shape. Clock hands, as found in Long Case Clocks can be made from mild steel sheet. A jewellers piercing saw works well for roughing them out. With practice, very little filing is needed to finish the hands.
Steve R.

used
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Hi Dean, I have made long thin hands, easy, really. Take some thin steel, drill & ream the centre hole, make up a filing bush (2 halves) with a centre register to suit the hole, bushes held together with a small countersunk screw tapped into 1 half, file to this (carefully) then as a previous poster said, clamp between 2 pieces of steel & file 1 side, reposition & repeat. If I was making really long slender hands, I would glue a piece of steel the same thickness as the hand, on the other edge of the clamps so that they remained parallel.
Hope this helps, Ian Sutherland, Down under.
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I've done things like that with a jeweler's saw and really fine blades. Thin brass sheet is backed up with some thin plywood, cement it down. The guys doing intarsia do similar things. If you use a fine enough blade, you don't have to do much finishing on the edges. I supposed if you've got a high-end jigsaw, one of those could be used, too.
You can also use a chemical metal etch to cut through thin brass sheet, the resist can be either photo-sensitive and a mask used, silk-screened on or hand-drawn. It takes some care to keep from getting undercutting on fine details like your pointer tip. I like ammonium persulphate for etching copper-based alloys, ferric chloride may be a little more available from Radio Shack.
Stan
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