Hi again
I've been toying with an idea of building a machine to recycle used shotgun shells, as our sports shooting club ends up with half a million of these per year and they just end up in the land fill as such as due to the lead residue the plastic isn't recyclable. There is 1.6 tons of metal and 2.1 tons of plastic in those shell casings.
The metal however is recyclable as is the plastic ring in the bottom of the shell, as it hasn't come in contact with lead. So both of these could be recycled and only the plastic casing would go to landfill.
Option A: Just shred everything (link) and do a metal/plastic separator, but that way some of the plastic ends up in the metal as it doesn't ensure it gets separated in the shredder.
Option B: Make a machine that pulls the plastic casing out of the metal base, pops the plastic bottom off and thus separates each shell in to three different bins. The plastic casing could then be shredded to reduce it's storage size, so the garbage truck wouldn't have to visit so often, which leads to savings.
Option C: Pull/rip the plastic casing off the metal, shred all the plastic and recycle the metal. Somewhat easier to do mechanically, but this puts the HDPE plastic to landfill that could be recycled.
My initial plan here is to try and go with option B and do a completely electromechanical machine, meaning plug it in and that's it. No hydraulics, no pressurised air, no electronics. I've been trying to find examples and only found two from YouTube (link 1 and link 2). Both seem to operate a little bit differently but in the end accomplish the same thing I've been thinking.
Now my problem is in designing a good gripper to grip the plastic casing so it doesn't slip when pulled. The first machine on Youtube seems to be using a hydraulic jaw configuration which presses against a mandrel and the second one has some sort of camming plate that again cams against a mandrel.
Do you guys have any good ideas on how to make the gripper part function mechanically? I've been thinking of putting stiff tool springs behind the jaws that are then operated with a knee-type linkage joint from the middle, so that at one end of the stroke the jaws will be forced open and at the other end the knee-joint is "broken" so the spring will force the jaws in contact for the pull. The actual jaws would be somewhat serrated probably unless a smoother version grips the same.
Also, couple of minute details: Most of the shells are of the size 12/70, but some 20 gauge is also mixed in as well as 16 gauge and once a year .410" is found. I have a feeder designed that will line up everything the same way and rejects any non-shot shells and separates the odd-ball calipers to a separate bin based on their size (basically move them over different hole sizes and they drop once a correct hole is found).
I've been toying with an idea of building a machine to recycle used shotgun shells, as our sports shooting club ends up with half a million of these per year and they just end up in the land fill as such as due to the lead residue the plastic isn't recyclable. There is 1.6 tons of metal and 2.1 tons of plastic in those shell casings.
The metal however is recyclable as is the plastic ring in the bottom of the shell, as it hasn't come in contact with lead. So both of these could be recycled and only the plastic casing would go to landfill.
Option A: Just shred everything (link) and do a metal/plastic separator, but that way some of the plastic ends up in the metal as it doesn't ensure it gets separated in the shredder.
Option B: Make a machine that pulls the plastic casing out of the metal base, pops the plastic bottom off and thus separates each shell in to three different bins. The plastic casing could then be shredded to reduce it's storage size, so the garbage truck wouldn't have to visit so often, which leads to savings.
Option C: Pull/rip the plastic casing off the metal, shred all the plastic and recycle the metal. Somewhat easier to do mechanically, but this puts the HDPE plastic to landfill that could be recycled.
My initial plan here is to try and go with option B and do a completely electromechanical machine, meaning plug it in and that's it. No hydraulics, no pressurised air, no electronics. I've been trying to find examples and only found two from YouTube (link 1 and link 2). Both seem to operate a little bit differently but in the end accomplish the same thing I've been thinking.
Now my problem is in designing a good gripper to grip the plastic casing so it doesn't slip when pulled. The first machine on Youtube seems to be using a hydraulic jaw configuration which presses against a mandrel and the second one has some sort of camming plate that again cams against a mandrel.
Do you guys have any good ideas on how to make the gripper part function mechanically? I've been thinking of putting stiff tool springs behind the jaws that are then operated with a knee-type linkage joint from the middle, so that at one end of the stroke the jaws will be forced open and at the other end the knee-joint is "broken" so the spring will force the jaws in contact for the pull. The actual jaws would be somewhat serrated probably unless a smoother version grips the same.
Also, couple of minute details: Most of the shells are of the size 12/70, but some 20 gauge is also mixed in as well as 16 gauge and once a year .410" is found. I have a feeder designed that will line up everything the same way and rejects any non-shot shells and separates the odd-ball calipers to a separate bin based on their size (basically move them over different hole sizes and they drop once a correct hole is found).
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