Hi there,
I was just wondering how I would go about accurately setting the length of the ejector pins in a plastic injection mould.
My first instincts are to put all the pins in the mould with the plate retracted and mill the cavity in one and the pins will be machined with it. However will the ends burr over making them stick. I am making the mould out of aluminium so a hard steel ejector pin in the middle of a lump of ally would be like your rip saw finding a nail in a chunk of wood! And would you set aluminium feeds and speeds or steel feeds and speeds?
Do I add the pins to the core after? If so would it be recommended to drill from the back of the mould plate breaking into the mould area, or drill in from the mould core/cavity area through the plate risking damage to the cavity?
Or perhaps drill the ejector pin holes first before anything is cut? Or would all these holes cause many interupted cuts playing havoc snapping my tiny mould finishing cutters (0.2-0.5mm).
If I drill them after the cavity is cut, how to I make them an accurate length so as to leave as little marks on the part as possible? What sort of length accuracy am I shooting for 10-50 micron?
What if the end of the pin is not flat but forms part of the mould contour? Does this ever happen and therefore require pins that do not rotate in the holes?
Can anyone shead any light on this mysterious side of mould making.
Using a Haas VMC/solidworks to make the mould. Have made simple moulds before but none with an ejector mechanism other that my fingers!
And yes I am spelling Mould with a 'U' as I am british.
Dom:drowning: