Re: Pictures of Tools
As promised, I've posted some pix of Accurail's injection molds. Molds are hard to photograph in the press; the press usually doesn't open enough to really see the mold cavity, so I dragged a couple open on the mold maintenance bench for a better view. View the pix at:
The "Open 'n Close" mold isn't very exciting; this is the style used to make what modelers call a "flat" kit and also detail sprues for other kits. In the trade this is refereed to as an open n' close tool because that's all it does; no side pulls, lifters, or unscrewing mechanisms, it simply closes, makes a part, and opens again. I've included a photo mainly to illustrate the Master Unit Die Co. system of interchangeable tooling inserts that fit a common frame; this explains why some of our tools don't have a complete ejector box. The photo of the two slide mold open on the bench illustrates this pretty well, with the spring loaded ejector plate showing behind the "B" half. the "A" (stationary) half is turned so one can see the features of both and how they interact. Surface mounting the "locks / wedges" with dowel pins is the quick and dirty way of doing it; sufficient for the relatively low molding forces involved in filling those little sill steps.
The larger mold on the bench makes the body for the USRA hopper family. It's usually pretty hard to see the core and slide faces since the slides closely surround the core, so I've removed one slide and placed it on the bench. The "cavity" (stationary) side actually makes the bottom of the car, with the blocks that core out behind the ladders projecting outward. Note how the cavity is pocketed deeply into the mold base, so that the wedges that lock the slides in place when the mold closes have a lot of steel behind them for support. Long pipes carry cooling water into the side actions to remove heat; there are other water circuits into the core and cavity that are not as obvious.