A little DIY (pic heavy)
Discussion
Take three pieces of horn plate and laminate them
Pre cut slits for the strap recesses on the mill to avoid splitting when they are machined out later later
Make a fitment that I can screw the horn block to so that I can reverse and replace it
First cut goes most of the way through the horn leaving a 1mm "window" at the bottom. This becomes the display back.
More shaping for the movement with space for the GMT setting pusher and a recess for the crystal. The case is very much a front loader as it is carved into a solid block.
Set up the whole fitment with the case off centre on the rotary table to cut the sides of the case. This is where I need to be able unscrew the case from the fitment and reverse it to machine the other side then fit it back in the original position, hence the reason for not holding it directly on the mill.
Cant the mill head to chamfer the edges on the same radius curve as the sides.
Finally off the rotary table/fitment and into a vice to machine between the pre-cut slots for the strap fitting. Without the sawn slots the horn will split and crack if it is milled in this direction.
Shaping all finished. Just a a couple of holes to drill for the stem and the GMT setting pusher, then polishing.
As the case is a front loader with no access to the rear of the movement at all, the stem can't be removed in the usual way. This is overcome with a two piece stem. I don't much care for a click fit type solution so I want a sliding fit where the two parts of the stem slot together like a jigsaw puzzle piece.
First cross drill a piece of pivot steel with a carbide drill.
Turn down the end to match the original stem and file the winding square.
This is the female part of the stem, it needs to end most of the way through the cross hole, so part it off just beyond
Mount it in a pin vice in a graver sharpening goniometer so I can grind the end perfectly square and grind away the edge of the hole.
On a separate piece of pivot steel, sized to match the stem hole in the case, file "jigsaw" piece on the male part of the stem to fit into the hole in the female
A little adjustment to ensure a sliding fit.
And into the case. The female part stay in the movement and will slot down over the male part when they are properly aligned allowing the movement to fit into the case.
Now it needs a crown. Take a hunk of damascus steel and soft solder it to a brass carrier that I can fit in a lathe or collet on the rotary table.
Drill the centre and a circle of holes
Mill away the stem fitting and half the circle of holes
Unsolder it from the carrier and do bit of chamfering on the watchmakers lathe then polish, etch in ferric chloride and polish again.
Unfortunately due to a camera memory card failure I don't have pictures of the dial making process apart from a before and after.
Starting with a chunk of damascus steel, I rough cut a disk, faced in in on the watchmakers lathe soft soldered it to a carrier as with the crown and turned it down to thickness. I then moved it to the rotary table on the milling machine and drilled it then took it off the carrier. Hard soldered dial feet, polished, etched and re-polished, then lume into the marker holes.
I also lost the pictures of adding the GMT complication to the movement, which entailed milling out a couple of recesses on the dial side of the main plate and pressing in pivots for 2 extra wheels and a click. One wheel is driven by the minute wheel and carries 2 fingers 180 degrees apart. The other wheel is a 24 point star wheel with a click to make it locate positively. The finger on the driven wheel advances the star wheel one tooth every 30 minutes thus giving a second hour hand that will show the half hours too. Also a pusher to manually advance the hour wheel for setting the time zone.
Turn up and press in the case pusher for adjusting the GMT hour hand, add a shark skin strap and give to wife for her birthday.
The horn is so translucent that it has a natural display back.
Pre cut slits for the strap recesses on the mill to avoid splitting when they are machined out later later
Make a fitment that I can screw the horn block to so that I can reverse and replace it
First cut goes most of the way through the horn leaving a 1mm "window" at the bottom. This becomes the display back.
More shaping for the movement with space for the GMT setting pusher and a recess for the crystal. The case is very much a front loader as it is carved into a solid block.
Set up the whole fitment with the case off centre on the rotary table to cut the sides of the case. This is where I need to be able unscrew the case from the fitment and reverse it to machine the other side then fit it back in the original position, hence the reason for not holding it directly on the mill.
Cant the mill head to chamfer the edges on the same radius curve as the sides.
Finally off the rotary table/fitment and into a vice to machine between the pre-cut slots for the strap fitting. Without the sawn slots the horn will split and crack if it is milled in this direction.
Shaping all finished. Just a a couple of holes to drill for the stem and the GMT setting pusher, then polishing.
As the case is a front loader with no access to the rear of the movement at all, the stem can't be removed in the usual way. This is overcome with a two piece stem. I don't much care for a click fit type solution so I want a sliding fit where the two parts of the stem slot together like a jigsaw puzzle piece.
First cross drill a piece of pivot steel with a carbide drill.
Turn down the end to match the original stem and file the winding square.
This is the female part of the stem, it needs to end most of the way through the cross hole, so part it off just beyond
Mount it in a pin vice in a graver sharpening goniometer so I can grind the end perfectly square and grind away the edge of the hole.
On a separate piece of pivot steel, sized to match the stem hole in the case, file "jigsaw" piece on the male part of the stem to fit into the hole in the female
A little adjustment to ensure a sliding fit.
And into the case. The female part stay in the movement and will slot down over the male part when they are properly aligned allowing the movement to fit into the case.
Now it needs a crown. Take a hunk of damascus steel and soft solder it to a brass carrier that I can fit in a lathe or collet on the rotary table.
Drill the centre and a circle of holes
Mill away the stem fitting and half the circle of holes
Unsolder it from the carrier and do bit of chamfering on the watchmakers lathe then polish, etch in ferric chloride and polish again.
Unfortunately due to a camera memory card failure I don't have pictures of the dial making process apart from a before and after.
Starting with a chunk of damascus steel, I rough cut a disk, faced in in on the watchmakers lathe soft soldered it to a carrier as with the crown and turned it down to thickness. I then moved it to the rotary table on the milling machine and drilled it then took it off the carrier. Hard soldered dial feet, polished, etched and re-polished, then lume into the marker holes.
I also lost the pictures of adding the GMT complication to the movement, which entailed milling out a couple of recesses on the dial side of the main plate and pressing in pivots for 2 extra wheels and a click. One wheel is driven by the minute wheel and carries 2 fingers 180 degrees apart. The other wheel is a 24 point star wheel with a click to make it locate positively. The finger on the driven wheel advances the star wheel one tooth every 30 minutes thus giving a second hour hand that will show the half hours too. Also a pusher to manually advance the hour wheel for setting the time zone.
Turn up and press in the case pusher for adjusting the GMT hour hand, add a shark skin strap and give to wife for her birthday.
The horn is so translucent that it has a natural display back.
Edited by Tanguero on Sunday 9th February 22:28
NeMiSiS said:
Excellent post, love it, not sure if I like the watch but that doesn't matter as you could make anything.
PS. My Wife likes the watch so it must be a girly thing.
To be honest - its not entirely to my taste either, but it is to my wifes which is what matters. As you say - its a girly thing!PS. My Wife likes the watch so it must be a girly thing.
NeMiSiS said:
sorry to turn off the main road..but
I have been thinking about this build thread for a while, and I have wondered why I took an instant dislike to the look of the watch.
I now know why, deep in a dark corner of my tiny brain there is a memory of my Mum washing my mouth out with soap, a special 'treat' for swearing.
This is the soap.........
I have been thinking about this build thread for a while, and I have wondered why I took an instant dislike to the look of the watch.
I now know why, deep in a dark corner of my tiny brain there is a memory of my Mum washing my mouth out with soap, a special 'treat' for swearing.
This is the soap.........
I can well understand why that would put you off!I know it isn't everyone's cup of tea by any means, however the finished watch looses a lot by only being seen in pictures. What attracted me to horn is the tactile properties. It is warm to the touch and has a smoothness and lightness that metal can't approach. It is difficult to describe but at the risk of departing into woo-woo language it really does feel palpably organic. My wife claims that it is the most comfortable watch to wear that she has ever owned.
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