sprue puller

I finally have my Boy 15S injection molding machine up and running and I found a MUD frame on Ebay and ordered a set of aluminum mold plates. I was about to order some injection pins to make my first mold and realized that I will need to have a sprue puller in the mold and a sprue ejection pin.

Looking online I found these sprue lock bushings, but it seems that there are not many different types of premade bushings available.https://us.misumi-ec.com/vona2/detai...079910/?Inch=0

My question is do most people buy the sprue puller bushings like this already made or do they just machine a sprue puller into their mold cavities?

If people are machining them into the cavity can someone share with me a design for one with a cold slug well that is good for both ABS and polycarbonate? Also, is there a recommended reverse taper cutter that can be recommended for machining the sprue puller cavity. Obviously, this needs to be done at the correct depth and angle to work well. I am not sure where to buy this odd cutter.

Also, what diameter sprue ejection pin would you normally use on small molds and how much larger should I ream the hole for it? It would be great if someone could recommend a specific part number of pin to use.

Thanks in advance for any advice you can give me on this.

In the cold slug area of the spruce puller pin, just use a ball shape burr bit to create an under cut.

look at danly/DMS uk. meusburger or hasco for standard parts

go here: https://na.dmecompany.com/Catalog/Ca...ilId=357&NSM=Y Download the cad model of any of these sprue puller bushing, and copy their geometry.

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Originally Posted by brian257

I finally have my Boy 15S injection molding machine up and running and I found a MUD frame on Ebay and ordered a set of aluminum mold plates. I was about to order some injection pins to make my first mold and realized that I will need to have a sprue puller in the mold and a sprue ejection pin.

Looking online I found these sprue lock bushings, but it seems that there are not many different types of premade bushings available.https://us.misumi-ec.com/vona2/detai...079910/?Inch=0

My question is do most people buy the sprue puller bushings like this already made or do they just machine a sprue puller into their mold cavities?

If people are machining them into the cavity can someone share with me a design for one with a cold slug well that is good for both ABS and polycarbonate? Also, is there a recommended reverse taper cutter that can be recommended for machining the sprue puller cavity. Obviously, this needs to be done at the correct depth and angle to work well. I am not sure where to buy this odd cutter.

Also, what diameter sprue ejection pin would you normally use on small molds and how much larger should I ream the hole for it? It would be great if someone could recommend a specific part number of pin to use.

Thanks in advance for any advice you can give me on this.

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You don't need a bushing, the sprue ejector pin should be at least as big as the largest diameter of the sprue taper or how big you make the cold well hole 10mm or .375" for most smallish molds

The cold slug ejector pin can be used as a Z pin puller or a 5 degree dovetail cut into the cold slug hole which I like the best, you only need a bushing if you want the mold to last a very long time 100,000 plus molded parts and even then the rest of the molds ejector pins holes are worn by then so not worth the extra cost in the long run a snip of a cold well design 2 of the best most common methods