I'm going to curve the back section to get rid of the right angled edge. I've written this g-code routine already for the top watch section so I'll use it again. Strictly speaking the back section is not supposed to be an ellipse shape, but if I tweak the parameters then it becomes a very shallow ellipse and will be fine for this initial design.
Tag archives: lathe
Making a watch case (part 16), adding some curves
Making a watch case (part 15), fitting the back glass
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Machining and gcode,
Making a Watch.
I'll be using a flat watch glass for the back section which is quite a bit smaller, in diameter, than the front watch glass. First, though, I cut the back ring diameter to match the middle watch section.
Making a watch case (part13), preparing the back section
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Machining and gcode,
Making a Watch,
Soldering and welding.
I make a recess in the middle watch section to take the back piece. I'm cutting down 2.0mm into the back of the middle section to leave a 1.7mm thick shelf inside the middle section. This gives strength and acts as a border between the top and bottom watch sections but I think it could be slimmer in future.
The middle section wall thickness is 0.5mm, so it's important to make sure the middle watch section is properly centered on the lathe before making this cut.
Making a watch case (part11), cutting the ellipsoid into the top section
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Machining and gcode,
Making a Watch.
To cut the ellipsoid shape into the top ring section I've programmed the ellipse in g-code so that the lathe table will follow this shape. The cut gets incrementally closer to the final cut. In the diagram, above, the solid white lines are the tool paths yet to be followed and the red ones are the paths already done.
On the final cut I increase the lathe spindle speed to give the finest finish.
Making a watch case (part10.5), putting a curve on the inside watch glass shelf
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Machining and gcode,
Making a Watch.
Going back over the photo's I remembered that I'd forgotten to include this bit, apologies about the 'part 10.5' but it fits between the part 10 and 11.
I'd like the edge of the watch-glass shelf to have some curvature so that it doesn't just end abruptly with a square edge. I'm going to use the lathe and some cnc to cut the curve.
Making a watch case (part 7), cutting the lugs into shape
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Machining and gcode,
Making a Watch.
The ring, now with lugs attached, goes back on the lathe. Since I'll be cutting the outside of the watch I put the clamps on the inside of the ring.
Making a watch case (part 3), turning the ring on a lathe
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Machining and gcode,
Making a Watch.
The ring is placed into a three jaw self-centering chuck. The three jaws automatically move together towards the centre of the chuck so the piece is automatically centred. If I've hammered the ring to a good circle then the ring should be pretty near centre too.