a silly mistake

Today I tried making a winding shaft for 02. Unfortunately, I made the slot for the pull out piece at an early stage with the result that it snapped into two while I was turning the other features. Here is a picture

This is the reason why I am maintaining a log for 02. I have made this mistake before & if I had documented it I could have saved half a days work. The log will be a sort of a detailed account of how the No.1 skeleton watch is made. So, I can read up the bit on winding shafts before making one for 03 or any subsequent piece. Over time & with practice I hope this knowledge will become intuitive.
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Anyway, I thought I might show you how I started work on this design. First of all, I required a 3D CAD model of the movement I had selected (the molnija 3602-3). Since I am an industrial designer I am fairly proficient with Rhinoceros (a 3D modelling software). So that is what I used. Below is an image of an early, incomplete model.

A 3D model would allow me to see the movement in a totally different perspective. I could also try as many designs/ themes with endless variations relatively quickly & without even touching a real movement. So I think the few weeks it took to make this model were well spent.
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The No.1 is a skeleton wristwatch. In the image below you can see the theme I selected. I wanted to lay bare the workings of a mechanical timepiece. What better way to do this than to accentuate the escapement.? Over time I developed this idea further through other devices (e.g.. finishes).

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Below is a 3D model of what the watch might look like. The case was imaginary since, at that stage, I had not selected one for my watch. This went through endless revisions, each element was changed & refined till I was satisfied with it. Mind you, the true test is when you finally make it. I had decided on a certain dial marker on CAD (after days of trying options & refinement) but it just could not be finished properly when I actually made it.
I hope I have better luck with the winding shaft tomorrow.