Making a watch case (part 5), adding the lugs

Making a watch case (part 5), adding the lugs

The centre ring needs two sets of lugs for the strap pin to attach to. The lugs need to angle somewhat, so as to wrap around the wrist. I'm not too sure what angle to use, so I've chosen 10° for this watch. As with all of this watch design, I'll feedback any alterations into the next iteration through the design.

I've cut four pieces of brass, as shown above, the fourth one is probably already in the vice when I took this photo! The vice is secured in a rotary table and I set the angle to 10°,

Setting the angle to 10°.

I think I'd already started cutting when I remembered to take this photo, as you can see all the chippings! The mill then makes forward and backwards motions, incrementally moving a small step to the left with the completion of every forwards and backwards motion. So the lug is quickly cut to the correct angle:

cutting the lug to the correct angle.

Next I put the ring in the vice and milled out a notch for the lugs to go:

Milling out a notch for the lugs to go.,

the inside space between the notches is 20mm, the calipers here are just to sense check, the mill itself accurately positions the cutting tool.

starting the cut

The cutting tool is 3mm in diameter and the lugs are 3.3mm, so I opened the notch a little bit by cutting two tracks 0.3mm apart.

putting both the notches into the ring

I centred the mill by centering it on the rotation table. The notches then need to be cut at equal positions either side of the zeroed axis.

Checking to see if the notch size is OK

Checking the notch size.

Great! they are secure but not too tight and they stand up by themselves. I don't want them too tight as I need to leave enough space for the solder to flow.

Next I rotate the table 180° to cut the other notches:

Cutting the notches in the other side,

when they're all cut it looks like this:

All the notches are cut,

Now we're finished with the mill for a bit, so take out the ring

All the notches cut and taken out of the chuck,

and it's time to get soldering!

 

 

 

Pingbacks are closed.

blog comments powered by Disqus