Project Notes

Original project by Jay Rugland:
https://www.thingiverse.com/thing:1248463

Blue Spade Terminals (Amazon Associate link):
https://amzn.to/2MJLz0C

Similar Dewalt 18 volt to Dewalt Lithium Ion 20 Volt Adapter, but w/ Battery Monitor
https://www.thingiverse.com/thing:1270617

$20 Surebonder Dewalt-to-Ryobi adapter:
https://surebonder.com/products/dew-20v-ryobi%C2%AE-to-dewalt%C2%AE-battery-adapter

They also make a Milwaukee-to-Ryobi adapter (Amazon Associate link):
https://amzn.to/2tinJB7

More project reviews:
https://www.youtube.com/playlist?list=PLHvctKwAXIO_ewpuKb1RXqez5NCSbeANj

Transcript

Hey, I’m Donald Bell for Maker Project Lab, and in this video I’m going to go over a project by Jay Rugland. This is an adapter that allows you to plug 20v Dewalt tool batteries into 18v Ryobi tools. I’ve built it and it works, but it’s not a slam dunk, especially since there’s a legit $20 adapter that does the same thing.

You can find links to everything I’m talking about in the description, but for this video, I’m going to walk you through what it’s like to build one for yourself.

So, here’s the problem. Ryobi doesn’t make a lot of great tools, but they do make a few useful ones that no one else makes — like this cordless glue gun, and this portable air pump. I love these, but it stinks to have a whole separate system of batteries I need to buy and charge.

With this adapter, I can run my Ryobi tools off Dewalt’s 20v batteries, which are close enough in voltage that it hasn’t caused any problems for me yet.

From the project page on Thingiverse you can download the three parts you need to make this. There’s the top, the base, and the clip—which you need to print two of.

I printed these up using standard PLA filament, and the settings called out in the guide.

In addition to the 3D printed pieces, you’ll need 4 machine screws and nuts, blue spade terminals, some short lengths of wire, some CA glue, and the spring from a retractable pen.

For what it’s worth, I probably should have used a thicker gauge of wire than the stranded hookup wire here, but it got the job the done. But if you’re moving a lot of current over a long time, these small wires might burn up. If you have thicker wire, use it.

I started with the spade connectors at the top. You have to remove the insulation around the connector, solder on the wire, and then snap it into place and set it with some CA glue.

Make sure to leave the wires a little long so they can reach out to the bottom connectors with room to spare. You can always tuck the extra wire up into the top piece.

Next you have to press fit the spade connectors into the bottom piece. This part is a headache on a lot of levels. You have to trim away some of the connector to get it in there. I wasn’t sure if the spades should be positioned closer in or further out. And I originally had them poking out pretty far and then later had to trim them back.

Long story short, you can save yourself a lot of stress by having a Dewalt battery nearby and testing to make sure you have the fit right before you glue the terminals in place. That said, my version is proof that you can go back in with some pliers and snips to tweak it and shave it down if you need to.

Once the spades were in and glued up, I soldered the wires to their corresponding connector, careful to keep positive on one side and negative on the other. Using different colored wire helps, and so does the positive and negative imprint on the top.

For the final step, you need to connect the top and bottom together while sandwiching the buttons and springs into the sides.

First, I cut my spring in half and then placed each piece in the little seat that’s built into the sides. Then you can put the top piece on while pinching the buttons in and test that everything fits the way it should.

I wish I had spent a little more time filing down the fit for the buttons because I have one that sticks a little, and I think that prevents it from latching into the tool as well as it could. So, don’t rush this part.

Next, place a machine screw through the top piece and use the little captive nut design on the bottom to get it tight. Jay says to use #6-32 x ⅜ screws, but I found those a little short and had to bore out the top holes to make them work. So if you’re at the hardware store, pick up a few longer options too—just not too long, or you’ll block the battery.

And at this step you’ll want to fit the battery to make sure the terminals slot correctly into the battery. Then, test it in a Ryobi tool to make sure it latches correctly into the tool and works.

As a final step, you can run a bead of CA glue around the seam between the top and bottom pieces to give it extra strength.

Now, would I recommend this as a project? Probably not. With a professionally made version of this available for $20, it’s just not worth the time and money to do it yourself.

Also, as Jay points out, there’s a real risk of over discharging your battery. Because 20v tools will often have battery protection circuitry in the tool and not the battery, you might run this down further in a Ryobi tool than you would in a Dewalt. Take it too far, and you risk fire or explosion, and if nothing else, an expensive battery replacement.

That said, if you’re in some Macguyver situation, or some country where the $20 professional option isn’t available, it’s cool to know that you can make your own.

There’s also another design by Jay where he adapts an 20v Dewalt Battery to run on 18v Dewalt tools, and in that design he includes a cheap RC low voltage alarm as a safeguard against over discharging. Adapting something like that into this design might be a good compromise, but again would add more expense and more time into an adapter you can buy for not that much money.

So there you go, that’s my project review for this 3D printed Dewalt/Ryobi battery adapter by Jay Rugland. You can find all the links in the description. And, if you appreciate me taking the time to build and review this project, you can buy me a coffee using the Buy Me a Coffee link down here. Alright? See you next time.