for those who keep asking me, I no longer have the plans for the trebuchet. This was designed and built my freshman year in engineering and I am now a second year graduate student. I no longer have the trebuchet either.I can tell you that when we built it we had two major problems. 1 The pivot point axle needs to be VERY strong. A standard steel pipe will bend in half so we used a sawed off axle from a tractor. one of those big farm types. 2 Quick release needs to be smooth, use a "panic snap"
@aharrin1 This is good to know. My engineering club is working on a trebuchet project this summer, and the strength of the throwing arm axle is definitely of concern. Do you have any recollection, however vague, on the forces imparted on the axle, if this was something you calculated or estimated?
@Zoidberg227 : yes you can calculate the forces imparted on the axle. But related to this calculation is a big tip that I have for you. Try and get the counter weights to fall as vertical as possible. This will impart the most amount of force to the sling and projectile. There will be two dimensions you can "play" with to do this which is the moment arm on the side of the weights and the 'pendulum' if you will, that hangs down from that moment arm....
@Zoidberg227 thus, if you can get the weights to fall nearly vertical, when they reach the bottom, they will have to make an immediate direction change. The forces on the axle are calculated by the force required to stop the counter masses from falling. The 'G's are fairly high and as I said in my previous comment, we used a standard steel pipe the first time and it bent in half. Use a solid steel rod and if you have access to a machine shop, have them polish it up to reduce friction.
one more comment @zoidberg227. If you or anyone in your engineering club knows MATLAB, you can derive the equations of motion for each part of the machine and create a simulation. The distances that are calculated won't necessarily be accurate but the trends will be correct. My junior year in college I did that for a final project for a class and was able to find a more optimal sling length and 'pendulum' distance. Also, the addition of wheels will increase the distance of the throw too
what is the total length of the arm, because i have one nearly the exact same , but with close to 200 lbs of counterweigth it wont throw a similarly weighted object more than 175 ft, just wondering if you could offer any sujestions
it is important that the sling be between 2/3 and 3/4 the length of the arm. One side of the sling is fixed permanently to the end of the arm while the other side of the sling has a metal ring. This metal ring slides on a strait metal rod also affixed to the end of the arm. As the centrifugal force increases throughout the swing, the ring will slide off. You may have to mess around with adjusting the angle the metal rod is at. You may need to tilt it forward about 10 degrees for optimum throw
Unfortunately I do not have the plans. My Intro. to Engineering class was over 3 yrs ago. The entire thing is about 12ft tall and the counterweight is offset from the pivot by about 2ft with 80lbs. You HAVE to use a solid steel rod of about 2" diameter otherwise the momentum from the weight drop will bend it. Hope this helps a little.
hold on hold on hold on hold on hold on hold on
48hash 2 months ago
Haha the oversized sling shot i made throws softballs, tennis balls and golf balls great distances. Not so much pumpkins tho lol
FussyCashew 2 months ago
Imagine loading it with M80s..
STFUbelgium 7 months ago
i bet it rolled another 100 feet though right? so it probably didn't actually shoot 400 feet.
crazypuma164 1 year ago
dang thats far
HardikG121 1 year ago
for those who keep asking me, I no longer have the plans for the trebuchet. This was designed and built my freshman year in engineering and I am now a second year graduate student. I no longer have the trebuchet either.I can tell you that when we built it we had two major problems. 1 The pivot point axle needs to be VERY strong. A standard steel pipe will bend in half so we used a sawed off axle from a tractor. one of those big farm types. 2 Quick release needs to be smooth, use a "panic snap"
aharrin1 1 year ago
@aharrin1 This is good to know. My engineering club is working on a trebuchet project this summer, and the strength of the throwing arm axle is definitely of concern. Do you have any recollection, however vague, on the forces imparted on the axle, if this was something you calculated or estimated?
Zoidberg227 7 months ago
@Zoidberg227 : yes you can calculate the forces imparted on the axle. But related to this calculation is a big tip that I have for you. Try and get the counter weights to fall as vertical as possible. This will impart the most amount of force to the sling and projectile. There will be two dimensions you can "play" with to do this which is the moment arm on the side of the weights and the 'pendulum' if you will, that hangs down from that moment arm....
aharrin1 7 months ago
@Zoidberg227 thus, if you can get the weights to fall nearly vertical, when they reach the bottom, they will have to make an immediate direction change. The forces on the axle are calculated by the force required to stop the counter masses from falling. The 'G's are fairly high and as I said in my previous comment, we used a standard steel pipe the first time and it bent in half. Use a solid steel rod and if you have access to a machine shop, have them polish it up to reduce friction.
aharrin1 7 months ago
@aharrin1 Thanks! Some of this is stuff we're discussing, and the additional input is much appreciated.
Zoidberg227 7 months ago
one more comment @zoidberg227. If you or anyone in your engineering club knows MATLAB, you can derive the equations of motion for each part of the machine and create a simulation. The distances that are calculated won't necessarily be accurate but the trends will be correct. My junior year in college I did that for a final project for a class and was able to find a more optimal sling length and 'pendulum' distance. Also, the addition of wheels will increase the distance of the throw too
aharrin1 7 months ago
do you guys have any plans on how to build this? its for a physics project. my e-mail Jakecommons@yahoo.com. thanks
XxxJcommonsxxX 1 year ago
@XxxJcommonsxxX see my post above
aharrin1 1 year ago
Can you guys launch anythign flaming?
JohnnyBoyCali 1 year ago
60 kg?
Snapx4000 1 year ago
How did u make the sling release on 1 side? i can figure that out? thanks.
KonaStinkyRid3R 1 year ago
what is the total length of the arm, because i have one nearly the exact same , but with close to 200 lbs of counterweigth it wont throw a similarly weighted object more than 175 ft, just wondering if you could offer any sujestions
MrSupersoccerstar 1 year ago
it is important that the sling be between 2/3 and 3/4 the length of the arm. One side of the sling is fixed permanently to the end of the arm while the other side of the sling has a metal ring. This metal ring slides on a strait metal rod also affixed to the end of the arm. As the centrifugal force increases throughout the swing, the ring will slide off. You may have to mess around with adjusting the angle the metal rod is at. You may need to tilt it forward about 10 degrees for optimum throw
aharrin1 1 year ago
nice but i need help with my sling plz help
mike88206 1 year ago
hold on hold on hold on hold on hold on , i am i am i am i am, lol nice trebuchet guys i made one and put a rock through my teachers window :P
gamertaav 2 years ago
nice! thats awesome!
wiimonster222 2 years ago
How should I go about building the release pin?
What should it look like?
richard0cheese 2 years ago
wow thats a lot of counter weight my floating arm throws 175 feet with about 30 pounds of counterweight
Madsmash92 2 years ago
Your FA treb is about 5 times more efficiant.
deathcrayon 2 years ago
more efficient yes but traditionally medieval i think not!
Epiphone101 2 years ago
kick ass
teoteagueosborne 2 years ago
how did you get it to launch? i saw you pulled a rope, but how was that attached to the trebuchet?
i got to build a trebuchet for school, and im trying to find the best way to launch it
TKDaddiction 3 years ago
its attached with an angled hook
bakkus1985 2 years ago
gj!
JoeDuke12 3 years ago
Thanks, me and a friend are attempting to build one about 6ft tall for a medieval history project so any advice is helpful.
truesdmf 3 years ago
try many different release angles and sling lengths, there is an optimum sling length and it makes a noticeable difference
aharrin1 3 years ago
Do you happen to have plans for this?
truesdmf 3 years ago
Unfortunately I do not have the plans. My Intro. to Engineering class was over 3 yrs ago. The entire thing is about 12ft tall and the counterweight is offset from the pivot by about 2ft with 80lbs. You HAVE to use a solid steel rod of about 2" diameter otherwise the momentum from the weight drop will bend it. Hope this helps a little.
aharrin1 3 years ago
wow
chuchudude 3 years ago