Balance Tack- Small Project

[steve855]

Hello All,

I haven't posted much lately because I haven't really done much lately. I had some free time this past weekend so I spent it in my workshop. A balance tack is a traditional lathe project and I needed one, so I figured I'd give it a try. The base is 7075 aluminum alloy because that's what I had on hand in the desired diameter. The black transition piece is black acetal, and the tapered shaft is brass. I wanted this to be easy to disassemble so it would fit in a shallow drawer, so the acetal piece has a 0.187" stub on the bottom that's a snug slip-fit with a corresponding hole in the center of the base. The brass portion is a press fit into the acetal. The perlage/spotting on the base was just for fun. Looking at the photos, I could have spent a bit more effort on smoothing the brass taper, but I ran out of time. Sometimes I have more fun making and modifying tools than actually repairing watches. Probably because the tools are not so small!

Thanks for looking

Steve

[Marc]

That is nicely done Steve. It's something I need to have a go at too, I have always got by without a balance tack but it's just lazy.

How did you do the perlage? It looks really good.

[Geo]

That's a very neat job Steve, it's obviously the deluxe model. I particularly like the idea of being able to disassemble the device for storage. :)

[steve855]

Marc- thanks, the perlage was actually not difficult. The base has a through hole in the center, I setup a pin this diameter in the drill vise with a crude paper washer slipped over it. The base was then slipped over this, allowing it to be rotated manually around the centering pin. I chucked a pencil eraser in the drill and spun it at moderate rpm, maybe 400-500.

I brushed a small amount of lapping compound onto the top surface of the base then started the first outer row of overlapping circles. With each circle I rotated the base by 1/2 eraser diameter, when the outer row was complete I moved the whole assembly over 1/2 dia with the Y axis and repeated this process until it was finished. It was fun watching the pattern appear, and no special equipment required, other than the mill/drill. I'll try to find a photo of this.

Geo- thank you, I don't have a dedicated watch workspace, so I keep all of my tools in a nice old Gerstner machinist's chest, and most of the drawers are shallow, so the ability to disassemble was important for me.

Edit- photo added

Edited January 5, 2016 by steve855

[Rafal]

great job, it looks very professional.

[atimegoneby]

Nice job Steve !  I like the engine turning technique.   

[steve855]

great job, it looks very professional.

Nice job Steve ! I like the engine turning technique.

Thank you.