I recently came into possession of 2 older 12V cordless Milwaukee power tools (a 3/8" impact socket driver, and a 1/2" drill) along with a huge lot of other tools. The (nicad) batteries were shot, and so was the charger.
Inspired by a few discussions here recently (http://www.garagejournal.com/forum/showthread.php?t=242599 and http://www.garagejournal.com/forum/showthread.php?t=242026 and maybe others?), and not wanting to part with these for cheap or buy another charger and cells for a repack (I've also already invested into the Ryobi 18V One+ ecosystem) I decided to make an adaptor for my existing batteries (4Ah li-ion).
Before I go further, I am aware that over-volting the drill and driver may shorten their lifespan. I have not yet tested them too extensively at 18V, but the life-giving 'magic smoke' hasn't leaked out so far, and they don't seem to overheat in testing. An extra little bit of ooomph doesn't hurt either
I started by tracing the bottom of one of my Ryobi drills (where the battery normally attaches) onto a thin sheet of polycarbonate.
After cutting the outer profile with a band saw, and the inner profile with a dremel, I fitted this onto a Ryobi battery until it securely locked in place. I epoxied another piece of polycarb to this sheet for a more secure fit.
I then removed the top half of the casing of the dead Milwaukee battery, and eye-balled a few band saw cuts so that it would fit atop the Ryobi battery at the right height to fit into the Milwaukee tools.
Just right!
I cut a few interlocking pieces of polycarb and epoxied them to the first polycarb sandwich and to the top of the Milwaukee battery casing.
While this cured, I took the terminals from the Milwaukee battery, and soldered these to terminals from the dead charger to fit onto the plastic tabs I created when cutting the Milwaukee battery.
These fit securely over the Ryobi battery terminals for a good connection. Most of the electrical is press-fit into place, and is later fully secured and protected with more polycarb/JB PlasticWeld (2-part hard epoxy for plastic).
Since I cannibalized the connection between the old Milwaukee battery and tools earlier (to cut about 2-3 inches of height from the adapter), I needed a way to secure the adapter to the tools. To do so, I drilled matching holes through the grip of the tools and the back of the adapter, having given myself plenty of clearance for the electricals. Putting layers of polycarb, PlasticWeld, and wood between the wiring and the holes, I secured the battery to the tools with an improvized hitch-pin (portion of head ground for clearance, threads ground away, hole drilled on the end) and a hitch-pin clip (note: this picture was taken before I ground the back-side of the head down).
From there, I covered my Ryobi battery with a very thin polyethylene garbage bag, and fitted the adapter over that, making sure that it locked into place on the battery. Using the JB PlasticWeld, I filled-in the polcarb structure I created so far, being careful to fill in all of the gaps for the best fit to the battery later on.
Because the PlasticWeld didn't stick to the garbage bag (didn't know this beforehand), the adaptor lifted right off of the battery, and the garbage bag peeled away with ease.
From here it was mostly a matter of finish. Since I didn't like the look of the fit of the adaptor to the tool, I put the garbage bag between the adaptor and tool, and filled in more gaps with PlasticWeld. After curing, I quickly sanded it to remove some of the wrinkles from where the bag was, and hit it with a quick coat of spray paint. It's a bit rough (I might smooth it out later), but it works perfectly.
This amounted to a total of about 1-2 hours of active work, with a few hours/nights of PlasticWeld curing thrown in.
Forgive me for any formatting issues/typos, as I typed this all out on my phone. Enjoy!
Inspired by a few discussions here recently (http://www.garagejournal.com/forum/showthread.php?t=242599 and http://www.garagejournal.com/forum/showthread.php?t=242026 and maybe others?), and not wanting to part with these for cheap or buy another charger and cells for a repack (I've also already invested into the Ryobi 18V One+ ecosystem) I decided to make an adaptor for my existing batteries (4Ah li-ion).
Before I go further, I am aware that over-volting the drill and driver may shorten their lifespan. I have not yet tested them too extensively at 18V, but the life-giving 'magic smoke' hasn't leaked out so far, and they don't seem to overheat in testing. An extra little bit of ooomph doesn't hurt either
I started by tracing the bottom of one of my Ryobi drills (where the battery normally attaches) onto a thin sheet of polycarbonate.
After cutting the outer profile with a band saw, and the inner profile with a dremel, I fitted this onto a Ryobi battery until it securely locked in place. I epoxied another piece of polycarb to this sheet for a more secure fit.
I then removed the top half of the casing of the dead Milwaukee battery, and eye-balled a few band saw cuts so that it would fit atop the Ryobi battery at the right height to fit into the Milwaukee tools.
Just right!
I cut a few interlocking pieces of polycarb and epoxied them to the first polycarb sandwich and to the top of the Milwaukee battery casing.
While this cured, I took the terminals from the Milwaukee battery, and soldered these to terminals from the dead charger to fit onto the plastic tabs I created when cutting the Milwaukee battery.
These fit securely over the Ryobi battery terminals for a good connection. Most of the electrical is press-fit into place, and is later fully secured and protected with more polycarb/JB PlasticWeld (2-part hard epoxy for plastic).
Since I cannibalized the connection between the old Milwaukee battery and tools earlier (to cut about 2-3 inches of height from the adapter), I needed a way to secure the adapter to the tools. To do so, I drilled matching holes through the grip of the tools and the back of the adapter, having given myself plenty of clearance for the electricals. Putting layers of polycarb, PlasticWeld, and wood between the wiring and the holes, I secured the battery to the tools with an improvized hitch-pin (portion of head ground for clearance, threads ground away, hole drilled on the end) and a hitch-pin clip (note: this picture was taken before I ground the back-side of the head down).
From there, I covered my Ryobi battery with a very thin polyethylene garbage bag, and fitted the adapter over that, making sure that it locked into place on the battery. Using the JB PlasticWeld, I filled-in the polcarb structure I created so far, being careful to fill in all of the gaps for the best fit to the battery later on.
Because the PlasticWeld didn't stick to the garbage bag (didn't know this beforehand), the adaptor lifted right off of the battery, and the garbage bag peeled away with ease.
From here it was mostly a matter of finish. Since I didn't like the look of the fit of the adaptor to the tool, I put the garbage bag between the adaptor and tool, and filled in more gaps with PlasticWeld. After curing, I quickly sanded it to remove some of the wrinkles from where the bag was, and hit it with a quick coat of spray paint. It's a bit rough (I might smooth it out later), but it works perfectly.
This amounted to a total of about 1-2 hours of active work, with a few hours/nights of PlasticWeld curing thrown in.
Forgive me for any formatting issues/typos, as I typed this all out on my phone. Enjoy!
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