Ok... Help.

There was a movie I saw in the 70s.  And a sequel.  Maybe more.  The movie might have been made in the 60s.  Had a Brady Bunch look to it.  So you know the California color palette right there.

I might have seen it on a Sunday on the Wonderful World of Disney.

In it, there was a boy-genius type.  Engineer.  Maybe 13 or 14 year old  He made mechanical gizmos.  He had a tough older sister that was sort of the muscle.  He was always inventing stuff in his basement workshop and using mechanical schemes to foil the villain, with the help of the neighbor kids.  Often involving rolling old tires down hills.

To get into his shop you could use a slide or come down the stairs.  This is key.  Be careful coming down the stairs.  As there was a boxing glove on a spring booby trap that you'd activate with a pressure plate on the stair tread. 

Like this.  Well, sorta.  That's a lift jack with the same principal.



What I need from you....  What was the name of this movie or set of movies? Google hasn't helped me.