I was thinking of doing the same thing (building a boomerang) and I was thinking if somehow you could get it so that the chain drops slightly when a lever is hit by the train while accending the hills. Be a nightmare to work out, but it would be way cool if it worked. BTW for those of you looking for a Screaming Serpent set (or two or three) I saw a crap load of them down at Le Target for 79.95. You way want to check out your local Target store. Our local one had like 10 of em.
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Bob Hansen
New Top 5:
5-MF; 4-X-Flight; 3-Hulk; 2-Kraken; 1-Raging Bull