R3verb
Well-Known Member
So the other day, my son Jack (who's 2) and I went out to our local park to fly some small stuff. Because he's 2 and has a short attention span, I had everything read to go. Igniters in rockets, chutes packs, the works. We launch our first rocket (a Der Red Max on a C6-5), goes great. The remaining 4 rockets didn't fly because my controller was OUT OF BATTERIES. I was pissed and it sent me down the rabbit hole of designing a launch controller that would charge via USB like EVERYTHING ELSE IN MY LIFE. My idea was simple: convert an old Estes Electron Beam launch controller that I had from using 4 AA batteries to something that charged via USB.
My original though was to use 3 18650 cells is series to get ~12 V. After a lot searching, I wasn't coming up with a good way to charge 3 cells from a single USB connector. There are lots of projects out there that use little boards to charge a single cell but I wasn't finding anything that could do multiple. I ended up posting on the 18650 subredit () and one user pointed out that you can use USB-C Decoy devices to get a predictable voltage from a USB bank via Power Delivery (PD). These little boards are about $2 a piece so I figured it was worth a shot.
A few days later, these little guys showed up from Amazon:
Some quick testing with a USB bank and a multi-meter showed 9V, just like the packaging said. I crudely used some jumper wires, connected it to a good Estes controller, hit the button and poof, igniter goes off like I hit it with a 9v battery. So I knew in theory this would work.
My next goal was to use as much of the Beam as possible. I jumped into fusion 360 and, with some patience and some digital calipers, faithfully recreated the important parts of the beam and 3d printed my first test:
Version 1 had some issues, holes weren't cut through, bulb holder got messed up, but the layout was pretty much spot on so I started the iteration process, each time getting closer and closer to something that would work:
By my 3rd print I had everything perfectly lined up and working. I had to add some stabilizer pieces and some new holes for the board and a new LED to show that the controller was powered but V3 was basically ready for parts:
As you can see, I'm using most of the original parts from the Estes controller; the button, the bulb, the key and the 3 metal pieces are all from the original controller.
Next, it was time to wire it all up and make sure it was all going to work:
While it looks like a lot, there's not a ton going on here. A simple circuit to light an LED to show that the controller has power and then a connection to the + and - ends of the controller (not shown) was all that was needed. With all of that done, I made some final changes to account for things like how to get the wires out, a back, some cosmetics to make the face look more like the original and sent it to the printer:
It's printing right now.........
I've got the rest of the pieces on the way and should be here over the next 2 days. I'll let you all know how it turns out! Additionally, once it's done and I prove that it works, I'll publish all of the 3d print files and links to where you can get the stuff I used.
My original though was to use 3 18650 cells is series to get ~12 V. After a lot searching, I wasn't coming up with a good way to charge 3 cells from a single USB connector. There are lots of projects out there that use little boards to charge a single cell but I wasn't finding anything that could do multiple. I ended up posting on the 18650 subredit () and one user pointed out that you can use USB-C Decoy devices to get a predictable voltage from a USB bank via Power Delivery (PD). These little boards are about $2 a piece so I figured it was worth a shot.
A few days later, these little guys showed up from Amazon:
Some quick testing with a USB bank and a multi-meter showed 9V, just like the packaging said. I crudely used some jumper wires, connected it to a good Estes controller, hit the button and poof, igniter goes off like I hit it with a 9v battery. So I knew in theory this would work.
My next goal was to use as much of the Beam as possible. I jumped into fusion 360 and, with some patience and some digital calipers, faithfully recreated the important parts of the beam and 3d printed my first test:
Version 1 had some issues, holes weren't cut through, bulb holder got messed up, but the layout was pretty much spot on so I started the iteration process, each time getting closer and closer to something that would work:
By my 3rd print I had everything perfectly lined up and working. I had to add some stabilizer pieces and some new holes for the board and a new LED to show that the controller was powered but V3 was basically ready for parts:
As you can see, I'm using most of the original parts from the Estes controller; the button, the bulb, the key and the 3 metal pieces are all from the original controller.
Next, it was time to wire it all up and make sure it was all going to work:
While it looks like a lot, there's not a ton going on here. A simple circuit to light an LED to show that the controller has power and then a connection to the + and - ends of the controller (not shown) was all that was needed. With all of that done, I made some final changes to account for things like how to get the wires out, a back, some cosmetics to make the face look more like the original and sent it to the printer:
It's printing right now.........
I've got the rest of the pieces on the way and should be here over the next 2 days. I'll let you all know how it turns out! Additionally, once it's done and I prove that it works, I'll publish all of the 3d print files and links to where you can get the stuff I used.
