I've gotten hooked on these laser cut metal and wood models that are on the market...I prefer the ones that do something once their together...walk, run...some really neat automobiles and truck kits...No glue, unless you break
something...Snap together..and they stay that way after I've played with them...Steel springs and rubber bands are the primary source of movement..although I just finished up one that has a tiny solar panel on it...Do a google on wood mechanical models and you'll find a bunch of different brands..ugear..rokr..wood city....Excellent for the parents and kids to work on together...This is the one with the solar panel...