Quirky Turn Mill Build

[vtcnc]

And here is a first casting of the linear bearing housing. As you can see it's a little tight on the pipe rail. That's because I didn't allow enough clearance on the foam pattern. I could probably bore it out further, but will probably adjust the CNC code for a little more clearance, cut more patterns and re-cast.

A second casting attempt failed because the metal wasn't hot enough to completely fill the mold. Metal mus be very hot for casting this way, because of the thin part, and because the metal must also flash out the foam before filling the mold.

I do find that the lost foam process is slower for multiple parts than conventional wood pattern casting. You have to re-make the pattern for every failure, which includes making sprues and attaching them, dipping the pattern and drying it for 24 hours. In contrast, a wooden pattern can be re-used as soon as it is pulled from the drag, and you can pour multiple parts at once if you have enough flasks, and the crucible capacity for it.

The pour is also relatively unpleasant for lost foam by comparison. Flames and smoke erupt, and the metal looks dirty. In conventional casting, it's relatively quiet, and odor free, and the metal is bright and shiny.