I made this tonight. It's stupid but fun It automatically presses the A button over and over again on a Nintendo 3DS.
Mk II Update:
I have replaced the K'Nex rods which were pushing down on the A button with a column of bricks. I did this because the K'Nex rods were too narrow and would sometimes move around inside the channel which led to the A button, causing them to go out of alignment and fail to trigger properly. I put a smooth piece on top of the column of bricks so the axel glides over the top. Doing this allowed me to also shorten the channel leading to the A button and therefore make the arrangement of the gears a bit neater. It is now 100% reliable and never fails to trigger. I've ground through 600 playcoins this morning without any interaction (other than starting it off and resetting the playcoin count to 300 between runs).
MK I:
The gears slow down the rate of button presses:
The final axel presses down on a rod inside the chimney part which is positioned over the A button:
So for every rotation of the axel, the A button will be pressed once. There's also a brick behind the R button to make the animation run faster:
(Sorry for the disgusting condition of the grey baseplate in that picture. It's the only one I had spare and I got it in some Lego someone gave me - none of my own Lego would be in that condition...)
I want to add a potentiometer so I can get better control of the speed of the motor. Here's a video of it running:
Mk II Update:
I have replaced the K'Nex rods which were pushing down on the A button with a column of bricks. I did this because the K'Nex rods were too narrow and would sometimes move around inside the channel which led to the A button, causing them to go out of alignment and fail to trigger properly. I put a smooth piece on top of the column of bricks so the axel glides over the top. Doing this allowed me to also shorten the channel leading to the A button and therefore make the arrangement of the gears a bit neater. It is now 100% reliable and never fails to trigger. I've ground through 600 playcoins this morning without any interaction (other than starting it off and resetting the playcoin count to 300 between runs).
MK I:
The gears slow down the rate of button presses:
The final axel presses down on a rod inside the chimney part which is positioned over the A button:
So for every rotation of the axel, the A button will be pressed once. There's also a brick behind the R button to make the animation run faster:
(Sorry for the disgusting condition of the grey baseplate in that picture. It's the only one I had spare and I got it in some Lego someone gave me - none of my own Lego would be in that condition...)
I want to add a potentiometer so I can get better control of the speed of the motor. Here's a video of it running:
Last edited by mashers,