tumbler mods
Posted: 01 Feb 2016 20:53
i did some research and decided i'm going to clean brass by wet tumbling with stainless steel pins. harbor freight sells two versions of a rock tumbler, one with a single drum and one with a dual drum. both got decent reviews from reloaders and a local sale combined with a 20% off coupon was too good to pass up. so, for under $40 i brought home the dual drum machine.
i knew opening the drums was going to be a pain, but the reviews didn't do this engineering nightmare justice. the drums have an outer cap that must be pried off with a screw driver and an inner cap that you have to use a pliers to get out. multiply that misery by two drums, and it was obvious something had to be done. i also have no doubt that over time, tearing the tops off the drums will lead to a catastrophic failure.
the interweb is full of folks who have used other kinds of jars in place of the drum on the single machine, but i couldn't find a suitable jar with the right length and diameter for the double machine. i did find a post about a guy who used a pvc tube and rubber bands (for added traction) and i decided to try his method, with a slight twist. below are some pics of the drum i made for the dual machine.
materials include a 2 ft length of 4" diameter pvc pipe, a 4" test cap, a 4" test plug, pvc primer and glue, some duct tape, a spray can of plasti-dip, and a 9/16 hex nut. the pvc tube was cut to 9.5" using a hacksaw, and a bench sander was used to smooth/even it out. the test cap was glued on one end using pvc primer and glue. the other end gets the removable test plug, which comes with a wing nut. the wing nut needs to be replaced by the hex nut so it clears the frame of the machine when it is spinning. from the unused part of the pvc pipe, a piece 7.75" long x 1.5" tall was cut and glued inside the pvc tube (butting up against the test cap). this actuator helps move the brass / pins around, so they don't just lay on the bottom of the drum when it rotates. finally, the pvc tube is too smooth to rotate on the tumbler so some form of friction must be added. people have used rubber bands and even the extra drive belts that come with the tumbler. i tried to replicate the pebbled, rubbery surface of the original drums by wrapping the pvc tube in duct tape and liberally spraying 6 coats of plasti-dip around it.
harbor freight dual drum rock tumbler with diy single pvc drum. the drum is opened and closed by loosening or tightening the hex nut on the end of the test plug.
red test plug on left and inside of pvc drum showing actuator on right.
i knew opening the drums was going to be a pain, but the reviews didn't do this engineering nightmare justice. the drums have an outer cap that must be pried off with a screw driver and an inner cap that you have to use a pliers to get out. multiply that misery by two drums, and it was obvious something had to be done. i also have no doubt that over time, tearing the tops off the drums will lead to a catastrophic failure.
the interweb is full of folks who have used other kinds of jars in place of the drum on the single machine, but i couldn't find a suitable jar with the right length and diameter for the double machine. i did find a post about a guy who used a pvc tube and rubber bands (for added traction) and i decided to try his method, with a slight twist. below are some pics of the drum i made for the dual machine.
materials include a 2 ft length of 4" diameter pvc pipe, a 4" test cap, a 4" test plug, pvc primer and glue, some duct tape, a spray can of plasti-dip, and a 9/16 hex nut. the pvc tube was cut to 9.5" using a hacksaw, and a bench sander was used to smooth/even it out. the test cap was glued on one end using pvc primer and glue. the other end gets the removable test plug, which comes with a wing nut. the wing nut needs to be replaced by the hex nut so it clears the frame of the machine when it is spinning. from the unused part of the pvc pipe, a piece 7.75" long x 1.5" tall was cut and glued inside the pvc tube (butting up against the test cap). this actuator helps move the brass / pins around, so they don't just lay on the bottom of the drum when it rotates. finally, the pvc tube is too smooth to rotate on the tumbler so some form of friction must be added. people have used rubber bands and even the extra drive belts that come with the tumbler. i tried to replicate the pebbled, rubbery surface of the original drums by wrapping the pvc tube in duct tape and liberally spraying 6 coats of plasti-dip around it.
harbor freight dual drum rock tumbler with diy single pvc drum. the drum is opened and closed by loosening or tightening the hex nut on the end of the test plug.
red test plug on left and inside of pvc drum showing actuator on right.