First time I seen one of your molds Brian, I noticed in the first picture a fan gate is used to fill the cavity. I have so many questions, shrink, venting, mold base etc. Maybe some day we can chat. I am ordering a brand new CNC so my old one will be open to mold possibilities. Thanks for the picture, would love to visit a foundry like yours, made 100's of plastic injection molds and maybe I can make one for the old Wilton bases everyone looks for. I know these are a little easier and not so precise then the ones I used to build.
Bummer - you must have missed my posts a few months back discussing a similar situation which eventually led to comments about "fly-specking" vises for errors like this.
The gate you see is fed from the bottom into two cavities simultaneously. The idea is to reduce the velocity of the metal into the cavity to prevent erosion of the mold and to reduce oxides that form from turbulent metal flow. Setting up a perfect sprue, runner, gating, and risering system takes years of experience or a computer simulator like "Magma" to get it right. My expertise is with the molding materials (sand & binder systems) and not gating/risering. I merely know enough to be dangerous
I have the stated goal of making my own vise here, but I either need a complete vise which will act as a pattern, or a mechanical drawing (we use Solidworks) of one that can be cut into a wood pattern using our cnc mill. The nice thing about a drawing is that I could make the pattern any size I want!
I'll bet you could arrange to visit a local college/university in your area that has a foundry program and get a tour. Check the American Foundry Society's (AFS) website for a local chapter and send them an email requesting a list of schools with foundry programs.
Brian
