Phred, on 13 December 2011 - 07:29 AM, said:
I found q big struggle to be a good sling and its release (in real life and Lego).
I couldn't tell what type of ammo you were using from the video, but I would suggest using a train magnet.
Hopefully that ammo won't be too large.
Also, to Legoize you counter weight, you may want to try Boat Weights. I don't know if they'll be heavier than dimes. They're a 2x6x2 brick filled with metal for the ballast of older floating boat sets (see below).
Yes, I originally didn't really care if it fired, but I was convinced through comments that making it fire would take it up about 3 notches. The sling is made of some thin string and a chunk of ribbon. I used a "jump ring" on the loose end of the sling, and it simply slips off of this piece
when it is firing.
I was firing a 2 x 2 round light bluish gray brick. Shoots that pretty well. I think the magnet would be about the right size, but it might be a bit too heavy. I could certainly make the ropes on the sling longer and maybe then I would get more power/distance behind the throws, but it fires pretty well right now.
I certainly considered the boat counterweight. I think it might be a bit heavier than the dimes, I have one somewhere but it would take some time to dig it out. biggest issue with the boat counterweight is that it is bright red and the counterweight on the treb is only 6 studs long. I could devise a plan to cover the ends as they would be showing on the counterweight as it is built now, but I haven't tried yet.
My current project for Avalonia is giving me a chance to build another (but somewhat different) trebuchet, so maybe the boat weight will be used there.