Base Frame

As mentioned earlier, the project begun as a run of the mill kids toy. However, soon after acquiring the bike I stripped it down to the bare frame by removing all the unnecessary pieces.

The Motor Mount

The first upgrade was motor. I purchased a larger 48 volt brushless electric motor to replace the old brushed one. However, the upgrade forced me to create a motor mount as the old one was simply too small. This mount was simply welded in place of the previous one.

The Battery and Battery Mount

In order to power this machine my friend gave me his old ebike battery. However, when I received the battery there was no output voltage. To diagnose the issue I carefully cut the shrink wrap coting off. This gave me access to the BMS and all the cells. Once I measured the cells voltage I realized that Battery pack was still in good condition. The BMS had simply shut off in order to protect the cells. I was able to circumnavigate this issue by disconnecting the BMS and charging unprotected. Once the battery was in a healthy voltage range I was able to reconnect the BMS and charge regularly. Pictured is the battery part way through the initial revitalization process.

In comparison to the rest of the project the battery was large. This made it a bit of a challenge getting everything to fit. After thinking about the design for a little while I decided that the battery should be orientated vertically. This then allowed me to place the pack on the right side of the frame. To do so I welded together a shelf that battery could be tied too using hose clamps.

Speed Controller

To mount the speed controller I created a similar set up on the opposing side of the bike. Rather than creating a shelf I simply welded on a plate with a couple mounting holes for the speed controller.

Cosmetics

After attaching the speed controller, I added in a couple mounting holes for a wire management box and voltage step down. The step down gave me a 12 volt power source which I wired to a headlight.