Merlin 2008 Trebuchet

[ACDC5968]

Quick question with King Arthur I've notice that it fires the pumpkin but the sling stays on the pin could you tell me why that is

[chrisg2004]

@ACDC5968

Sure. On King Arthur, one of the things I think is very dangerous is to have the ring flailing around after the throw - it is just too dangerous. I use a basket ball net for a pouch. One end is closed (the top end of the net) and the other end is attached to the release ring. The closed end is attached to the TA. When the ring releases, it allows the pumpkin to role out of the pouch. There is a 4 foot extension on the ring (attached to the TA) that hangs onto the ring.

Chris

[ACDC5968]

I personally believe that Merlin can do over 2000ft but do you think the that it's firing to high

[chrisg2004]

Sure,

Merlin is 50 feet high

Chris

[rocketavocado]

Ive seen other videos of Merlin, but none told me how high it is. Could you tell me that?

[chrisg2004]

WSWarthog,

It gets better.... If you look up and down the Trebuchet line last year - of all the machines that were there, only one was of Medieval design. All the rest were engineering inventions.

Chris

[WSWarthog]

I've been watching some videos of catapults/trebuchets/ballistas and found the range achieved to be quite tepid but I think 1400 ft would have made any Roman or Crusader proud.

[ACDC5968]

Have you ever thought about talking out the cross bracing at the top so you don't have worry a out the pumpkin hitting the bar so you could get a farther distance.

[chrisg2004]

@ACDC5968 Yes. I've discussed this with my team and it would take some work to make it viable. I still come back to the point that if it is hitting the cross bar - the throw is too low to begin with. This is the biggest reason I haven't done it yet. Who knows - I might still do it.

Thanks for your thoughts,

Chris

[ejflesher]

That is one impressive design.

[JamesThWilliams]

To determine the efficiency of the trebuchet you need to find the mass of the falling object then measure how far it falls. Then you need the velocity and mass of the projectile as it is released. Once you have those measurements it's a simple matter of comparing the potential energy of the falling mass to the kinetic energy of projectile. Simply divide the kinetic energy of the projectile by the potential energy of falling mass then multiply by 100 there's your efficiency.

[Necatour]

Thanks for your comments Chris. As you've for sure been studying a number of different designs, would you regard this one as the most "efficient" far (output in regards to CW compared to KA, FAT, FAKA or whipper)?

[cjgerow]

Yah - I guest it is the most efficient since I don't have any counter weight except for the weight of that L shaped carriage.

My very first throw in 2007 was cocked to the beginning of the J track (about 1/3 way up) - and that went 950 feet.

[Necatour]

This is more or less an F2K but with a different design. The only key difference is the coupled TA.

[cjgerow]

I was intrigued with the FAT design, but it had problems. 1) The fastest timing on the arm was when it was going horizontal. This meant you had to do funny things to get the payload to release at 45 degrees. 2) the CW had to go through a slot on the horizontal track. It hit this part when it was exerting the most force. 3) the limit to how high you can raise the CW was determined by the length of the TA (as in an F2K). Thanks for your comments.

ChrusG

[angagaur]

It's much closer to a floating arm whipper than a FAKA.

The guy who built this, invented King Arthur Trebuchets.

Merlin defines the term efficiency.

It's competetive with machines like Yankee Seige and Pumpkin Hammer using NO counterweight beyond an empty sled and the mass of the arm itself.

If you get much more efficient than this, you'll be producing free energy.

[cjgerow]

Thanks for your comments. We are having a lot of fun with Merlin and King Arthur.

ChrisG

[shifforbrainz]

that is why this thing may be realy cool but it may not be the most efficent thing. (just a question, do you compeat in an contest or do you just know alot about trebs and catapults)

[shifforbrainz]

it is like a cross of a floting arm and a faka, thats pritty cool!

[LINKedup101]

An FAKA is a floating arm trebuchet and a king arthur trebuchet combined already. >_>

[shifforbrainz]

yes but this is not a FAKA treb

[LINKedup101]

Yes, but mixing a floating arm trebuchet with something that is already floating arm seems a bit redundant.