... width of the centre pad are adjustable for best results. Or by setting the clearance to zero you can revert to the normal prototype design. It is easier to see without the rail in place: 2_011241_550000000.png The end clearance is visible here at A: 2_011242_350000000.png The remaining dimensions of the key are taken from the entered rail section dimensions. The keys can be set for left or right hand drive, and the amount of key remaining projecting is random for each key. You can see that in this side-on view: 2_011244_220000000.png It would all look more intelligible with the chair jaws in place, so that's the next job. In the meantime, I think I will have a nice boiled egg. Martin. posted: 1 Aug 2018 18:52 from: Andrew Barrowman Martin Wynne wrote: Andrew Barrowman wrote: It would be better if you could adopt the rail top as the z-datum, because all the code here is based on that. It would remove one extra thing to go wrong. Hi Martin, Perhaps, but it ...