... Barrowman Some chairs are a bit trickier than others. Chairs like the ubiquitous S1 are fairly straightforward because the jaws are normal to the base, but crossing chairs and some of the check chairs have jaws that are rotated from the normal. And they are not just simply rotated. The jaw casting forms a parallelogram with one axis aligned with the base and the other axis aligned with the rail. Here's one way to produce angled jaws. Starting with the base plate, the solid line represents the gauge face of the rail. 2983_041946_070000000.gif This is it in wire-frame plan view. Green lines are construction lines. 2983_041946_070000001.gif Now we drag the seat on to the base and snap it to the intersection of the center-line and the rail. 2983_041946_070000002.gif The seat is actually a block that can be used repeatedly in any model. If a block is edited any changes will be immediately replicated in all instances of the block. (And blocks can be nested. For example, a chair screw can be a block and if I edit it all the ...