Tuesday, March 1, 2016

Apollo 13: moon magnet is GOOOOOOOOO!

*phew* what a ride it's been with Apollo 13, but I am ecstatic to report the moon is back in action and kicking butt.

We replaced the banged-up magnet, the shorted coil, and rebuilt the moon driver board.
Then we replaced a bunch of stuff on the control board, which might have ended up being unnecessary.  Why?  Because we had the wrong transistor on the moon aux driver board!
We used an IRF540 transistor, instead of the proper replacement IRL540.
Huge thanks to Ottawa tech Sylvain for spotting our problem.

Either way, here it is in glorious action.


All that remains is fitting a new plastic above the moon standups so that the ball doesn't get stuck in there.  I had tried re-glueing and reinforcing the broken old plastic, but that lasted less than a day with the ball getting whipped at it.


  1. Ive been following your saga because I too just bought an apollo 13 that has magnet issues. The moon moves as it should but the magnet doesn't grab or hold the ball. I'e checked the coil and it's 4.4 ohms so I believe it to be good. The fuse under the PF tests good. Where is the moon driver board exactly? I think that's my next suspect. THANKS!

  2. My wires were broken but they looked fine. Works great now. Thanks for your info.

    1. Hi, so sorry I didn't get the chance to respond to your question in time, but happy to know you solved your issue.