Replacing batteries in 3DBotMaker finish line

redlinederby Monday, 12/5/2016
Site manager

I know several of us have the 3DBotMaker electronic finish line. It uses 3 AAA batteries...well, the batteries in mine leaked or whatever and now the thing isn't turning on.

My immediate plan is to just replace the battery pack but in thinking more long term, does anyone have an idea on how to possibly make a power adapter for it?

I'm an electrical dolt so I have no real clue where to start or if it's even possible...or maybe one of you have already made one? 


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72_Chevy_C10 12/6/16
Event coordinator

I can do a thread for this when I get a chance, Brian. I used an old phone charger to power mine. They should be 4.5 volts. If you strip the wires in a phone charger, there will be 4 wires...a red, black, green and a white. The green and white are for information...don't worry about them. The red and black are your positive and negative. All I did was tape up old batteries (so, they don't make any contact), and pinched the red wire on the positive side of the finish line and the black goes to the negative side....pretty simple, and everyone has an old phone charger laying around

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redlinederby 12/6/16
Site manager

I have an old charger from my Android way back was a USB wall wart though, suppose the voltage will always be the same regardless, yes? Nifty...I'll try to dig it up and see if I can verify that it's 4.5v somehow.

It's definitely an article that I think people could use and get some traction otherwise. Might sell a few more of the finish lines too...

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