Main plate holder [watchmaking]

The purpose of this quick report is just that - to provide an update to those who follow our watchmaking progress. Also, we feel that sharing our trials and tribulations may one day help someone on their own watchmaking journey.

Last week we started to prototype the main plate. The main focus was on positional tolerances and working out the 'perfect' press fit for the main train jewels. But it wasn't long until we figured out that we are wasting too much material; precisely over 60%. In addition, our work holding method was excellent in relation to rigidity, however, our solution would be very inefficient for mass production - even a quantity of just a dozen pieces at a time.

We had two options: To continue with prototyping or to pause and find a better clamping solution before we go any further. I voted for the first option: to keep learning and not to worry about waste. However, I was quickly outvoted by Josh (who already had Andrew on his side). The final straw was a video which clearly shows a very effective mainplate holding solution on Willemin Macodel CNC, as demonstrated at Baselworld in 2015.  Here is the link to it.  Definitely worth watching:

https://www.youtube.com/watch?v=dyqBtc-qXmE

In just 3 working days, putting in a solid 50 hours of work, Josh and Andrew designed, coded and manufactured our new 'clamp'. The benefits are already paying off: 

- we can use a smaller blank than before, while there is no compromise on rigidity;

- the brass waste is now below 50%

- the new work-holding piece allows for both sides milling plus 90 deg side cut without having to re-clamp the piece;

- and, most importantly, the new blanks could be clamped directly without pre-machining preparation which saves 25 minutes per piece!