# trying to build to overcome the plastic/metal problem



## ericrm (Oct 5, 2013)

in the next few month i want to try to deal with those little monster and im thinking about some kind of hammer mill, since i cannot afford one professionnaly made i will try to do one myself... i know my drawing are not exactly the best but i think you will figure ...
could this work? what kind of speed of hp im i seeking? for the speed im thinking to reduce the motor speed(i guess aroud 1750rpm) by 2 to get a little more force out of it.how much space (if i should have some) should i let between the hammer and the block between the hammer if i want an end product of around 1/16? i am not an engineer so every advice are welcome... i dont have put an exit because im not sure where to put it...


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## artart47 (Oct 5, 2013)

Hi !
I had the thought about liquid nitrogen and a devise like a punch-press that could slam the material while frozen.
Would it be feasible to load a devise like yours blast inside with the nitrogen then give it a fast spin ?
Per-haps one could process alot of material very quickly. Low power use may offset the N2 cost?
artart47


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## rusty (Oct 6, 2013)

ericrm without prejudice scrap your design and go back to the drawing board.

The 7.5 HP hammer mill with a 4 inch intake, by over feeding could almost stall the motor were you had to wait for it to regain RPM's. i always feared the motor would one day go up in smoke.

The hammers are hinged at the rotating shaft, similar to this primitive hammer mill shown below.

rusty


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## Woodworker1997 (Oct 6, 2013)

artart47 said:


> Hi !
> I had the thought about liquid nitrogen and a devise like a punch-press that could slam the material while frozen.
> Would it be feasible to load a devise like yours blast inside with the nitrogen then give it a fast spin ?
> Per-haps one could process alot of material very quickly. Low power use may offset the N2 cost?
> artart47


The problem you will have with blasting LN2 is that it does not like to absorb heat meaning, a gas cloud is formed between the object and the LN2 thus for a small period of time the part is insulated from loosing heat. If you wanted to get things as close to 77K as possible the LN2 would need to be in a vacuum dewar then add the parts to the dewar. This would allow for the gas cloud to dissipate and the nitrogen would "wet" the components and remove the heat from them.
They would then be very brittle and most likely break as you want them to.

Derek


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## chlaurite (Oct 6, 2013)

I see a lot of people proposing various solutions to removing pins from connectors, but just don't get the need. A pair of pliers, perhaps a good end-cutter, and you can obliterate most connectors in seconds.

Granted, I suppose that involves a few seconds' more work per connector than "throw it in the grinder/fire/mill and go get lunch", but I mean... You had to pop the connector off the board in the first place. It probably takes more total human time to handle it multiple times (remove from board, put in mill, separate out plastic from metal debris) than to just rip the pins out when you first pull it off the board, no?


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## ericrm (Oct 6, 2013)

claurite, like you said it is already a lot of time to remove them from the board and since i buy all my motherboard doing everything by hand become a 3$byhour paying job ,i want to go beside all that tedious and ineficiant work... also pulling 10 pound of pins is something on the blistered hand but make it 500 pound and many more to come and it become problematic.....


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## Smack (Oct 6, 2013)

That's a major issue when working with e-waste and obtaining material to process yourself, to handle it as little as possible. I would incinerate for the first step on anything your not going to take out of plastic. But here is a 8" rock crusher on ebay.


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## ericrm (Oct 6, 2013)

nice find Smack, i will send the pins pictures to the guy and see what he think, that would fall right in my amount of $.


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## Smack (Oct 6, 2013)

The problem your going to run into with any of this type of material is the heat that is generated during the grinding process. It will cause the plastic to get hot and can make a hard job even harder, that's why incineration is so important with this type of material. If you can get it, you could introduce some dry ice into the mix to keep the temp down and the stuff should break up nice. If it were me...well I think you know the direction I would go by now for any kind of volume. If you did do the dry ice way just think, if you did it in your garden it would really kick those plants into high gear from all that CO2 you'd be pumping out.


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## yar (Oct 6, 2013)

This might sound strange but you can take them and put them in a freezer overnight. The next day wrap them in a towel and beat them with a hammer. The plastic will shatter and then you have to just pick out the pins. 

There are also othe variations using 3 or 4 inch pipe with a nipple on one end. Fill it up and slam another piece of pipe into it crushing the plastic. 

I use the freezer for degaussing wire from televisions and monitors to make the tape brittle and easy to cut through with a razor. I also use it for circuit breakers to remove the buss bars and contacts.


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## Smack (Oct 6, 2013)

Yar, you mean a Mortar and Pestle right?


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## yar (Oct 7, 2013)

Smack said:


> Yar, you mean a Mortar and Pestle right?



Yes I guess that you could call the pipe set up a mortar and pestel.


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