Replies

1. 
   nazard | May 16, 2010 10:49am | #1

   I would use a piece of hemp rope to secure the arm, and sever it with a scaled-to-size battle ax....

2. 
   RalphBarker | May 16, 2010 11:09am | #2

   Trebuchet trigger

   Interesting project, Bret.

   I've been racking my brain, but I can't recall how we made the trigger back then.  ;-)

   I always thought it was rather avant garde for the Chinese to invent a machine with a French name, though.

3. 
   marking | May 16, 2010 11:54am | #3

   Trebuchet Trigger Help

   Cool project!! I've built small catapult "kits" for my wife's class when science fair time comes around (special ed  kids need a little help to join in on the fun)

   Check out Trebuchet.com.  Lots of kits, articles and pictures.

   I haven't seen how a traditional tebuchet trigger works.  If you don't want to use nails or screw-eyes ,  dowels and string could do the trick.

   Hopefully, i've attached a photo from  trebuchet.com  showing a string string stretched from side to side that holds back the throwing arm.   One end could have a knotted loop over a dowel pin.  Pull out the pin,  releasing the string,  releasing the arm,  dropping the weight, throwing the projectile and taking the castle!!!  (isn't this fun?!)

   Peace

   Mark

   (paraphrasing Monty Python)   "Have fun storming the castle!!"

   
4. 
   RalphBarker | May 16, 2010 06:32pm | #4

   Good thing for me that slinging trebuchet puns is a no-brainer, eh?  ;-)

5. 
   bduffin104 | May 16, 2010 07:32pm | #5

   Update, trigger problem solved

   I came up a foot activated hinged stirrup setup for a trigger. Works good.

   Initial test launch, 75 feet.

   After re-shaping the all important hook on the end of the throwing arm to delay the release point of the sling, I got 100 feet.

   I can adjust the length of the sling cords to try to find the optimum length.

   I don't think I'll add any more weight. I think I'm maxed out as far as what the frame work will handle.

   I can fiddle with the pivot points but I'm pleased with 100 feet on the maiden voyage!

   Photo #1: Loaded, cocked and ready to fire! 

   Photo #2: Closeup of foot activated dovetailed hinged stirrup trigger.

   Photo #3: Post launch position.

   Photo #4: Close up of wedged through tenon. The whole contraption comes apart for storage in about 20 seconds and a few taps with a rubber mallet.

   OK, what's next, Bret

   
1. 
   RalphBarker | May 17, 2010 10:11am | #6

   the trigger

   I'm a little concerned about getting an OSHA certification of the foot activated dovetailed hinged stirrup trigger, Bret. It strikes me that there is a distinct possibility of the projectile sling catching the chin that is attached to the activating foot with some force. ;-)

   Also, as a golfing machine, shouldn't it be on wheels?  ;-)

   Otherwise (and more seriously), I'm quite impressed by your work.

6. 
   WillGeorge | May 17, 2010 11:43am | #7

   I was thinking that a old French Guillotine type device would do if it has a very sharp blade and stopping block and is allowed in the 'rules of play'...

7. 
   powderjones | May 17, 2010 12:39pm | #8

   trebuchet trigger...

   I built one of these years ago.  I designed a sort of ratchet mechanism where the "geared" portion was incorporated into the base and the "tooth" portion was on the end of the swing arm.  When the arm was lowered into position, the "tooth" engaged the "gear".  To release the arm we would pull back the gear.  I'm sure there are several way to configure this.  I know I haven't used to correct terms for the parts - I hope I provided enough info to create your own picture of a solution.  It looks like fun - good luck! - Bob