# Custom 46mm Aluminum Watch



## Precise

Several weeks ago I wrote in this link

https://www.watchuseek.com/f222/pursuit-comfort-524056-post3833719.html

"The weight of heavy watches tends to rotate them from the flat of my wrist around to the bottom of my wrist. Round watches are more comfortable for me than my big square 46mm watches because the corner of the watch bottom (near 2 o'clock) pushes on my protruding wrist bone."

So I decided to try making a lightweight round case for my 46mm square Parnis which weighed 157 grams. I liked the looks of the simple, high-contrast dial. But rarely wore it because it was not comfortable.

The finished watch is the same diameter (46mm) and thickness (13mm), but its weight is 57 grams - exactly 100 grams lighter.

My original intent was to black anodize the aluminum. But I'll try living with the natural color for a while first.

Note that I've rotated the dial 30 degrees clockwise. It looks level when my hands are on my computer keyboard or steering wheel. Under these conditions it looks right to me. But when I'm not typing or driving, it looks a bit odd. Perhaps I'll get used to that. But if I get too used to it, my standard watches might start to look odd.

I chose a "lugless" case design. It was easy with this movement, which has a smaller diameter movement than the dial. The lugless design is also easier to lay out with a narrow strap. This one is only 20mm, which looks a bit too narrow on this 46mm case. I have some more 20mm straps on order, which may look better.

It was an enjoyable, though laborious project. The space is so tight that I first designed it in AutoCad, then machined it to +/- .002" tolerance.

And yes -- it is much more comfortable to wear than the original case.

Best,

Alan

Update: 4/20/11 I narrowed the ends of a few 22mm straps to fit this case. I like this size better than the 20mm strap first illustrated. I also like their textured leather. Three new pics follow:

Update 4/23/11 I added two more pics. 20mm black straps with yellow stitching. Cloth first, then leather - my current favorite strap for this watch.


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## sdeyer

Nice work! but I would definitely go with your first thoughts and get it anodized black.


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## mars-red

Very cool! I've thought about aluminum cases on occasion, as well - what grade of aluminum did you end up using? Did you pick a particular grade for specific reasons, or did you use whatever was available at the time?


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## Precise

mars-red said:


> Very cool! I've thought about aluminum cases on occasion, as well - what grade of aluminum did you end up using? Did you pick a particular grade for specific reasons, or did you use whatever was available at the time?


I had some 6061-T6 on hand. I have a slight preference for 7075, which is harder and machines a bit more cleanly. But 6061-T6 works well.

I've worn the watch (carefully) every day. The bezel is already showing fine scratches. If I get around to it, anodizing should harden the surface.

Though I had planned on black anodize, the color of aluminum is distinctive and stands out clearly next to the black dial. Black would tend to look like a lot of other watches.

Alan


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## David Woo

Precise said:


> Note that I've rotated the dial 30 degrees clockwise. It looks level when my hands are on my computer keyboard or steering wheel.


Well done, I like it. The rotated dial is a nice touch, kinda reminds me of those vintage military pilot watches in Konrad's book.


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## jlau_design

I really like your project. I am in the midst of designing a watch myself. I wanted to have a prototype done in CNC and aluminum seems to be a good choice. I also wanted to use it for its lightweight. 

Did you think of making more units of this model, or maybe new designs?


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## dannywong1190

Any chance you'll be making a few of these models for sale? I really love the rotated dial.


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## zsw

Well done! I think that face looks great in a lug-less, circular body...much better than in the B&R styled one. And the off-axis design really adds some intrigue to the overall aesthetic. have you seen this watch available from areaware? same off-axis idea (even called the off-axis) but the design is very dull...yours is vastly better. I'd go black with the body too.

again, nice job!

-Zach


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## Eraserhead

Looks amazing! keep the good work.


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## phattbam

are you taking orders??


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## jose-CostaRica

impressive work!!! looks awesome!!


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## brownie99

nice concept, there must be something going on with lugless cases and aluminum. i just finished such a watch and am starting to test the waters. my prototypes were in aluminum and loved them. i am producing in SS and 655 Bronze. take a look

http://www.kickstarter.com/projects/1918521259/tool-watch-a-tool-not-a-jewel?ref=email


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## tanwill

Wow nice aluminium case. 
Can you help me produce a similar case to fit a ETA 2824 or Seiko 7S26 movt ?


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## The Guvnah

That is a very handsome bit of kit, right up my street. Personally I wouldn't mind an ally watch taking its daily beating and acquiring a collection of dinks and 'hero scratches', I'm imagining the couplers on "Kwik-Form" ally scaffolding. It would be inevitable that it would end up looking like this but totally in keeping with the utilitarian nature of the metal. I certainly wouldn't be reaching for the Solvol Autosol every Sunday morning to give it a polish, I'd polish it at manufacture then let it oxidise naturally from that point on.

From observation I don't think anodizing will be the cure unless someone knows differently. Anodising will produce better scratch resistance but I doubt it'll protect it from a significant knock. A big point in its favour is that anodizing also lets one play with colour (including graduated colour effects) and I'm thinking a deep deep olive green or maybe a ('one shade away from black') midnight/petrol blue would be a show stopper.

Perhaps it might be possible to inset a discreet ring of stainless around the upper (and lower?) circumference as a bump ring? From there of course it's a short hop to engraving it (tachy, divers, wind rose etc) and enabling it to rotate.|>

Another dink mitigation strategy might be to machine a discretely raised ring of knurling around the case perimeter, I'd make it the same width as the crown and all the way round interupted only by a lightly milled relief where the crown sits.

The yellow script and markings are fabulous btw. What can I say but "top work fellah".


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## slikmetalfab

I am also developing an aluminum watch. This special grade of aluminum has a rockwell C scale of ~7 whereas type 316L s.s. has a rockwell C scale of ~10.

Pretty tough stuff. Once i finish my prototype, i will release the grade of aluminum to all here.

There is also (as you guys mentioned) anodize coatings and a multitude of other coating that we use in the tooling / mold industry to help with scratch resistance.

I will be posting all the info here withing the next 2 weeks and reveal the finished prototype.

Scott


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## Precise

Since my original post, I've made a rotating Delrin (acetal) bezel for this watch and many other watches. I like the functionality and the looks. It is also protective and easily replaced if damaged.

Alan


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## The Guvnah

Now that's thinking outside the box! Hopefully one will be included in the box? :-!


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## slikmetalfab

I really like this design and the Delrin ring is a great touch!

Are you planning on selling any soon?

Scott


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