I am going to try to answer without being confusing so bear with me
1.yes
2.,3.4.,5.,6.,7. you can purchase from MUD will be a basic mold base. It will include the "A" and "B" plates as well as the ejector plates. It will already have the leader pins and bushings installed. What you will have to do is add return and ejector pins. The reurn pins are a positive return on the ejector plate. You can put from 2 being min. and up to whatever you like but I usuallly use 4. The ejector pins are what you will use to push your part out/off with. These should be placed around to where they will push on the part. These can vary in size depending on what is needed where( I usually use D-M-E but other suppliers are available.). You can cut directly into the plates without any further working of them. The sprue hole does not always have to be tapered. It depends on how your runner and gate will be going to your part. It will also be determined on where you will shoot the mold from( either the center or the top as an example.) Don't forget you can also subgate the part if it is big enough. Air will not always escape from between the plates. This is where your ejector pins will come into play. Normally you will ream your ejector pin holes onsize and the ejector pins will usually come in from the manufacturer .0005 under. This allows for air and gas to escape. But this is not always enough, sometimes you will need to "vent" the mold. this is done by grinding a tapered relief on the face where needed starting at about .0005 deep out to whatever. Remember a general rule of thumb is plastic will usually not flash up to about a .003 gap, but this is extreme. The cooling channels or water lines will be done by drilling holes either straight through or connnecting them by drilling 3 hole( 2 one way and 1 cross and capping it off) so you can circulate the water through each side. Promenent placement would be directly behind/around your part but you must also consider where your return pins, ejector pins, cavity and cores lie so not to interfere with one another. Proper layout before cutting is sometimes very essential before making your mold.
Hope this helps out some and let me know if I can try to answer any more questions.  |