@tgmeier36 : if your contest is for accuracy, use a simple single arm pendulum style treb. Keeping things as simple as possible is a sound engineering principle. If there are other considerations in your contest (weight, height etc) let me know - the advice will change.
@ldvance01: You see, it's only supposed to throw at a fifteen feet target... Ergo it's judged for accuracy, but it's also judge on efficency. now I'm no expert at tRebuchets, but, the greater the efficiency, the farther the projectile goes? Correct me if I'm wrong, please.
@tgmeier36: Efficiency is measured as the energy of the projectile as it's released divided by the total energy available from the drop of the counterweight. My early MURLINS had 90% efficiency and shot 100 feet. My new treb has 42% efficiency but shoots 1100 feet. This is because the new treb has 110lb of counterweight and the old one had only 3 lb of CW.
If you need efficiency, build a Floating arm or MURLIN
@tgmeier36 : I think I use the same basic method many of the innovative treb designers use (see First in Fright or Merlin). Insight to a possible interesting design is followed up with a lot of simulation analysis. In short, detailed mathematical modeling and the resulting optimization you can get from that make a big difference.
i have wanted to build a trebuchet for a long time now and was wondering if you could email me the plans. I agree to all your terms. I just dont want to post my personal email to the public so if its ok with u plz send me a message. thanks
ldvance01: I am a 12 year old boy scout. I thought it would be cool to make a trebuchet. I have made many trebuchets before. when i saw your vid , it made me think i could hurl a baseball far to. please may you send me some plans. i will not tell any one about the plans with out your permishen. My emali is nichargrove@yahoo.com. thank you Nicholas H.
LDVANCE01: I am a Science Olympiad coach. My students found your videos on the Murlin. We would like to build one for our event this year. We agree to the two conditions for getting the plans. If possible, please send to strevena@gmail.com. Thanks!
Hey is there any chance i can get a copy of these blue prints? i'm a highschool student and I want to build a trebuchet this weekend, this seems like a really awesome plan. I agree to not distribute the plans under any conditions and i'll keep you updated on how it goes! Just email me if you can! jewig@student.oswego.org
The angle that the ball left at looks like 25-30 degrees. Would a release at 40-50 degrees have given better results? I am only saying this because I have always heard that 45 degrees is the optimal release point. Am I off on this? What do you think?
Can you send me the plans? I tried to constuct a trebuchet from the video but only got 100 yards from it. My E-mail is skippererickson@gmail.com. I agree to the conditions and will tell you on how it turns out.
CJ: I can certainly help you with plans to get you started. Doesn't the science olympiad make a smaller golfball sided trebuchet for their competition? I will need your email address.
My son and I just built a floating arm trebuchet for his World History Project. He is now hooked on the science of trebuchets and wants to build another one. We saw your video on your dynamically tuned one and really wanted to see if we could build it. Would it be possible to get the plans to your model which is going to be built for his upcoming High school science project.
alldoors@gmail.com I agree to not distribute the plans under any conditions. In addition I will document all phases of construction and post update images as we proceed. Since this is for his school project will stick to the plans. Once completed would like to experiment on it with some modifications.
@ldvance01 I had a question about the ball. Do you think that a baseball would fly further if the surface was deformed like that of a golf ball? Maybe press it in a spherical mold to change the surface area with impressions?
@dorkslayer2010 Dorkslayer: the short answer is theoretically no. The reason is that dimples reduce drag in a narrow range of airspeed velocities, and that velocity is about a factor of two lower for baseballs than golfballs. This means that dimples on a baseball would only help for velocities up to 80 mph, and start would hurt substantially at higher speeds.
@ldvance01 all agreed email: alldoors@gmail.com Will keep you updated on the progress of its testing. Once the class project is completed and graded we will begin experimenting with the design components to see if we can find some extra distance and efficiency
Can you adjust the angle of throw vertically? Also, can you please send me the plans? I want to build one, and I promise I won't tell them to anyone. Besides, the construction is pretty obvious from the video, and I could just figure it out myself by experimenting.
I teach Physics and Pre-AP Pysics. I would love to build this baseball trebuchet with my class. I agree to your conditions, would you share your plans with me, please? My email is khriskelp@gmail.com. Your help is greatly appreciated! Any other advise or suggestions are welcome!
¿CAN YOU SEND ME THE PLANS? PLEASE! I need them ! i've to build one of these Trebuchet in this week ! my e-mail oscar_aguirre_01@hotmail.com Please Help me :(
Cooool, We are home schoolers in Illinois and have built a couple trebuchets but were looking for something different for a catapult contest. Any chance we can get plans to build one of these? dakiteha@gmail.com. We will be throwing tennis balls. Please send release drawing as well. Thanks.
hey i have to make one for the science fair if you could send one to my email it would mean a lot to me and i agree to the conditions and i can send u pic updates every day. thanks jeremy my email is homeslicejw@gmail.com
hi, I'm looking to make a Trebuchet for a competition at a local woodland festival, could you possibly send me a design package? my emails phillbacon@yahoo.co.uk.
@ldvance01 It's my entire class, there's ten of us total. I also have friends and parents that are willing to help. Cost for supplies isn't really a problem, unless it's something monumental. If it doesn't seem like enough time, do you know of any other trebuchets or catapults we could make that would launch a tennis ball a reasonable distance? My e-mail is: joshnoble@comcast.net if that's easier for you. Either way, thank you so, so much.
Do you think i could get a design package as well? My western heritage class is having a trebuchet challenge for our final next thursday, and this is by far the best one i've seen. I've read your conditions, and they i certainly agree to them.
Yeah, that'd be great, thanks! School for me ends this week, and I have all summer to build and tweak it. I will definitely keep you updated with pics and a video once it's done.
I can send you a design package free, assuming you're OK with the following conditions conditions:
1) They're copyrighted, which means you can't copy or distribute them to anyone else without my permission.
2) You keep me up to date with how you are doing. I want to know how well the plans work for you and how the device performs when it's built. (pictures & videos too!)
Let me know if that's OK, and if so, give me an email address and I'll send it to you.
Hey, love the catapult! That thing is amazing. Would you be able to e-mail me detailed blueprints for that one? I mostly need measurements and angles of the throwing arm and sprockets, but the plans for the whole thing would be even better if it's not too much trouble for you.
I use a piece of 3/4" x 1/8" aluminum stock as the 'hook', about an inch and a half long with a 3/8" hole drilled through the middle so that I can hold it in place with carriage bolt and nut and lockwashers. The stock sticks out the front of the throwing arm, canted about 45 deg forward (more or less). I make a loop on the releasing end of the sling using a bosuns hitch and loop it over the front of the stock.
If this isn't clear, leave me an email address and I will draw you a picture
hey i am also doing this for a high school physics project...i have done most of it but my dad and i are having trouble with the sling and releasing...the hook on the throwing arm is giving us trouble...any advice? thanks please respond ASAP
Thanks for answering. I have a couple more questions and am going to start designing this thing soon. You said that there were three sprockets 20cm long? I see two, and then a shorter one, and then the one on the wheel. Also, where can I get good SPECTRA cord? Websites I found just had info about it. I'm still a little confused on the ramp, but I think I am starting to get it. Thanks again, can't wait to see your 100lb counterweight Murlin.
Also, which parts get the most stress and is a 3000 lb spectra cord overkill or needed? What is the "25cm" ramp for? The projectile being fired is a pretty hefty potato. Thanks again.
@Scrappingt0nVI : the CW cord has about 1000lb on it at the bottom of the throw, so that means 500 lb on each line. It's oversized to reduce bounce, which is the major source of energy loss for larger counterweights. The 25cm ramp is a circular segment of wood with a 25cm radius between sprockets 1 and 2. This reduces the maximum cord stress by about a factor of two. you can use cheap nylon cord, but you won't be able to push the CW mass up very high.
Hey Idvance01, I'm really interested in doing this trebuchet for a school project. The only limitation on the trebuchet is that it and the counterweight have to weigh less than 600 lbs, only performance is judged. I have a few questions after watching the video, and the other murlin videos, about 30 times :P. How hard is this thing to build and are there any specific ratios, such as each "leg" on the wheel's length/the base to the height of the frame that are important. Thanks.
@Scrappingt0nVI : from a ratio standpoint, if the throwing arm is 40 cm long, the first 3 (long) sprockets are about 20 cm apiece. The 4th one is 10 cm long and the last one (on the throwing arm itself) is about 3 cm from the axle. Precise tuning requires a simulation, but that should work pretty good.
@Scrappingt0nVI : re your question about building difficulty. I think you have to be a modestly capable woodworker to do this. plenty of strange angles and glue joints, but no special tools needed. Care must be taken making sure the left and right frame arms are identical so that the axles end up straight.
Comment removed
josefkrouza 1 month ago in playlist Uploaded videos
You see, I've this school project that you're only supposed to throw the ball a measly fifteen feet (That's where the target is).
Any suggestions from your most humblest proffesional opinion?
tgmeier36 1 month ago
@tgmeier36 : if your contest is for accuracy, use a simple single arm pendulum style treb. Keeping things as simple as possible is a sound engineering principle. If there are other considerations in your contest (weight, height etc) let me know - the advice will change.
LDVance
ldvance01 1 month ago
@ldvance01: You see, it's only supposed to throw at a fifteen feet target... Ergo it's judged for accuracy, but it's also judge on efficency. now I'm no expert at tRebuchets, but, the greater the efficiency, the farther the projectile goes? Correct me if I'm wrong, please.
tgmeier36 1 month ago
@tgmeier36: Efficiency is measured as the energy of the projectile as it's released divided by the total energy available from the drop of the counterweight. My early MURLINS had 90% efficiency and shot 100 feet. My new treb has 42% efficiency but shoots 1100 feet. This is because the new treb has 110lb of counterweight and the old one had only 3 lb of CW.
If you need efficiency, build a Floating arm or MURLIN
ldvance01 1 month ago
@ldvance01 Thanks for you help, Mr. Vance. I'll be sure to tell you the results of the competition.
tgmeier36 1 month ago
Did you design this yourself?
If so, HOW IN THE WORLD?
tgmeier36 1 month ago
@tgmeier36 : I think I use the same basic method many of the innovative treb designers use (see First in Fright or Merlin). Insight to a possible interesting design is followed up with a lot of simulation analysis. In short, detailed mathematical modeling and the resulting optimization you can get from that make a big difference.
LDVance
ldvance01 1 month ago
Comment removed
geonerd 1 month ago
i have wanted to build a trebuchet for a long time now and was wondering if you could email me the plans. I agree to all your terms. I just dont want to post my personal email to the public so if its ok with u plz send me a message. thanks
daboss11111 1 month ago
@daboss11111 : Certainly can send you the plans if you agree to the terms, but how do I send it to you without an email address?
ldvance01 1 month ago
@ldvance01 i will send you a message
daboss11111 1 month ago
Comment removed
josefkrouza 1 month ago
ldvance01: I am a 12 year old boy scout. I thought it would be cool to make a trebuchet. I have made many trebuchets before. when i saw your vid , it made me think i could hurl a baseball far to. please may you send me some plans. i will not tell any one about the plans with out your permishen. My emali is nichargrove@yahoo.com. thank you Nicholas H.
shellsiefly 1 month ago
LDVANCE01: I am a Science Olympiad coach. My students found your videos on the Murlin. We would like to build one for our event this year. We agree to the two conditions for getting the plans. If possible, please send to strevena@gmail.com. Thanks!
strevena 1 month ago
This has been flagged as spam show
Hey is there any chance i can get a copy of these blue prints? i'm a highschool student and I want to build a trebuchet this weekend, this seems like a really awesome plan. I agree to not distribute the plans under any conditions and i'll keep you updated on how it goes! Just email me if you can! jewig@student.oswego.org
Ewig315 2 months ago
The angle that the ball left at looks like 25-30 degrees. Would a release at 40-50 degrees have given better results? I am only saying this because I have always heard that 45 degrees is the optimal release point. Am I off on this? What do you think?
Thanks
Sigaddict 2 months ago
@Sigaddict I was going to say the same, but then had a think, and found this: Play with this applet. A baseball is 0.145 KG.
ht tp colon slash slash tiny dot cc/l2dey
Lighter projectiles, fighting air resistance need a much lower release angle than you might think.
geonerd 1 month ago in playlist More videos from ldvance01
ldvance01,
Can you send me the plans? I tried to constuct a trebuchet from the video but only got 100 yards from it. My E-mail is skippererickson@gmail.com. I agree to the conditions and will tell you on how it turns out.
Thanks
serick1234 2 months ago
CJ: I can certainly help you with plans to get you started. Doesn't the science olympiad make a smaller golfball sided trebuchet for their competition? I will need your email address.
LDVance
ldvance01 2 months ago
@ldvance01 I sent my email to you in a message. Thank you!!
noremac456 2 months ago
My son and I just built a floating arm trebuchet for his World History Project. He is now hooked on the science of trebuchets and wants to build another one. We saw your video on your dynamically tuned one and really wanted to see if we could build it. Would it be possible to get the plans to your model which is going to be built for his upcoming High school science project.
dorkslayer2010 2 months ago
@dorkslayer2010 : I can send over the baseball MURLIN plans (non-dynamically tuned) if you agree to the two normal conditions:
1) you will not distribute the plans to anyone else without my permission as they are copyrighted, and
2) You will let me know how the project goes and how far you throw. I use this info to help update my design package.
If you're OK with this, send me an email address and I'll send the plans over.
LDVance
ldvance01 2 months ago
@ldvance01
alldoors@gmail.com I agree to not distribute the plans under any conditions. In addition I will document all phases of construction and post update images as we proceed. Since this is for his school project will stick to the plans. Once completed would like to experiment on it with some modifications.
dorkslayer2010 2 months ago
@ldvance01 I had a question about the ball. Do you think that a baseball would fly further if the surface was deformed like that of a golf ball? Maybe press it in a spherical mold to change the surface area with impressions?
dorkslayer2010 2 months ago
@dorkslayer2010 Dorkslayer: the short answer is theoretically no. The reason is that dimples reduce drag in a narrow range of airspeed velocities, and that velocity is about a factor of two lower for baseballs than golfballs. This means that dimples on a baseball would only help for velocities up to 80 mph, and start would hurt substantially at higher speeds.
LDVance
ldvance01 2 months ago
@ldvance01 all agreed email: alldoors@gmail.com Will keep you updated on the progress of its testing. Once the class project is completed and graded we will begin experimenting with the design components to see if we can find some extra distance and efficiency
dorkslayer2010 2 months ago
Can you adjust the angle of throw vertically? Also, can you please send me the plans? I want to build one, and I promise I won't tell them to anyone. Besides, the construction is pretty obvious from the video, and I could just figure it out myself by experimenting.
pyrosimple 3 months ago
great design i love it
way2easy2love 4 months ago
AWESOME!!
I teach Physics and Pre-AP Pysics. I would love to build this baseball trebuchet with my class. I agree to your conditions, would you share your plans with me, please? My email is khriskelp@gmail.com. Your help is greatly appreciated! Any other advise or suggestions are welcome!
khriskelp 4 months ago
900 ft from a 70lb counterweight?
this thing is a feat of engineering.
volound 4 months ago
This has been flagged as spam show
¿CAN YOU SEND ME THE PLANS? PLEASE! I need them ! i've to build one of these Trebuchet in this week ! my e-mail oscar_aguirre_01@hotmail.com Please Help me :(
1993rakzo 4 months ago
I agree with your stipulations and would like to try and build this cooool Treb. Need to have it done in 4 weeks....any possibility of getting plans?
Thanks dakiteha@gmail.com
dakiteha 5 months ago
This has been flagged as spam show
Cooool, We are home schoolers in Illinois and have built a couple trebuchets but were looking for something different for a catapult contest. Any chance we can get plans to build one of these? dakiteha@gmail.com. We will be throwing tennis balls. Please send release drawing as well. Thanks.
FiedlerKim 6 months ago
Laxhobo:
I have sent you the plans. Let me know if there are any questions.
ldvance01 6 months ago
hey i have to make one for the science fair if you could send one to my email it would mean a lot to me and i agree to the conditions and i can send u pic updates every day. thanks jeremy my email is homeslicejw@gmail.com
laxhobo8 6 months ago
Yes, I can, if you agree to two conditions:
1) you cannot distribute the plans any further than yourselves as they are copywrited
2) you let me know how things are going as you build and test so that I can improve my plan package.
If you are OK with those, then let me have your email address and I will send the package over.
LDVance
ldvance01 6 months ago
Comment removed
laxhobo8 6 months ago
hey is this for me
laxhobo8 6 months ago
can u send me blue prints for my class please Thanks, Jeremy
laxhobo8 6 months ago
cool
lukasdererste 6 months ago
hi, I'm looking to make a Trebuchet for a competition at a local woodland festival, could you possibly send me a design package? my emails phillbacon@yahoo.co.uk.
thanks, phill.
philyyyyyyy 8 months ago
OK, I'll send the design package over.
ldvance01 8 months ago
Can I get a design package. I'm looking for something to do this summer. I agree to your conditions but I may have to scale the size down.
Frazlesnazle 8 months ago
nfraz729@aim.com is my email
Frazlesnazle 8 months ago
9 days is a little tight. How much help do you have?
ldvance01 9 months ago
@ldvance01 It's my entire class, there's ten of us total. I also have friends and parents that are willing to help. Cost for supplies isn't really a problem, unless it's something monumental. If it doesn't seem like enough time, do you know of any other trebuchets or catapults we could make that would launch a tennis ball a reasonable distance? My e-mail is: joshnoble@comcast.net if that's easier for you. Either way, thank you so, so much.
TheJoshisgood 9 months ago
Do you think i could get a design package as well? My western heritage class is having a trebuchet challenge for our final next thursday, and this is by far the best one i've seen. I've read your conditions, and they i certainly agree to them.
TheJoshisgood 9 months ago
Yeah, that'd be great, thanks! School for me ends this week, and I have all summer to build and tweak it. I will definitely keep you updated with pics and a video once it's done.
My e-mail is axecutioner999@yahoo.com
AxecutionerFC2 9 months ago
AxecutionerFC2:
I can send you a design package free, assuming you're OK with the following conditions conditions:
1) They're copyrighted, which means you can't copy or distribute them to anyone else without my permission.
2) You keep me up to date with how you are doing. I want to know how well the plans work for you and how the device performs when it's built. (pictures & videos too!)
Let me know if that's OK, and if so, give me an email address and I'll send it to you.
ldvance01 9 months ago
@ldvance01 would you be able to send me a design package, and i would be OK with the conditions. please, it's for a school project.
IrishSnipez 9 months ago
@IrishSnipez :
Can do. Send me an email address.
LDVance
ldvance01 9 months ago
Comment removed
AxecutionerFC2 9 months ago
Hey, love the catapult! That thing is amazing. Would you be able to e-mail me detailed blueprints for that one? I mostly need measurements and angles of the throwing arm and sprockets, but the plans for the whole thing would be even better if it's not too much trouble for you.
E-mail: axecutioner999
Thanks!
AxecutionerFC2 9 months ago
I use a piece of 3/4" x 1/8" aluminum stock as the 'hook', about an inch and a half long with a 3/8" hole drilled through the middle so that I can hold it in place with carriage bolt and nut and lockwashers. The stock sticks out the front of the throwing arm, canted about 45 deg forward (more or less). I make a loop on the releasing end of the sling using a bosuns hitch and loop it over the front of the stock.
If this isn't clear, leave me an email address and I will draw you a picture
ldvance01 10 months ago
@ldvance01 thanks very much i understand most of it but a picuter would be helpful if possible...my email is; dtkenyon75@yahoo.com
thanks a lot
SkullCrusherOO7 10 months ago
hey i am also doing this for a high school physics project...i have done most of it but my dad and i are having trouble with the sling and releasing...the hook on the throwing arm is giving us trouble...any advice? thanks please respond ASAP
SkullCrusherOO7 10 months ago
can u give me the plansof that
patduckys 10 months ago
@patduckys : yes, assuming you're ok with some conditions.
1) the plans are copyrighted, meaning that you can't copy them or give them to someone else without permission from me.
2) that you have a little patience. I need to pull together a reasonable design package.
and,
3) you send me back some feedback on how well it all worked. Even nicer would be some pictures or video.
LDVance
ldvance01 10 months ago
Thanks for answering. I have a couple more questions and am going to start designing this thing soon. You said that there were three sprockets 20cm long? I see two, and then a shorter one, and then the one on the wheel. Also, where can I get good SPECTRA cord? Websites I found just had info about it. I'm still a little confused on the ramp, but I think I am starting to get it. Thanks again, can't wait to see your 100lb counterweight Murlin.
Scrappingt0nVI 1 year ago
Also, which parts get the most stress and is a 3000 lb spectra cord overkill or needed? What is the "25cm" ramp for? The projectile being fired is a pretty hefty potato. Thanks again.
Scrappingt0nVI 1 year ago
@Scrappingt0nVI : the CW cord has about 1000lb on it at the bottom of the throw, so that means 500 lb on each line. It's oversized to reduce bounce, which is the major source of energy loss for larger counterweights. The 25cm ramp is a circular segment of wood with a 25cm radius between sprockets 1 and 2. This reduces the maximum cord stress by about a factor of two. you can use cheap nylon cord, but you won't be able to push the CW mass up very high.
ldvance01 1 year ago
Hey Idvance01, I'm really interested in doing this trebuchet for a school project. The only limitation on the trebuchet is that it and the counterweight have to weigh less than 600 lbs, only performance is judged. I have a few questions after watching the video, and the other murlin videos, about 30 times :P. How hard is this thing to build and are there any specific ratios, such as each "leg" on the wheel's length/the base to the height of the frame that are important. Thanks.
Scrappingt0nVI 1 year ago
@Scrappingt0nVI : from a ratio standpoint, if the throwing arm is 40 cm long, the first 3 (long) sprockets are about 20 cm apiece. The 4th one is 10 cm long and the last one (on the throwing arm itself) is about 3 cm from the axle. Precise tuning requires a simulation, but that should work pretty good.
ldvance01 1 year ago
@Scrappingt0nVI : re your question about building difficulty. I think you have to be a modestly capable woodworker to do this. plenty of strange angles and glue joints, but no special tools needed. Care must be taken making sure the left and right frame arms are identical so that the axles end up straight.
ldvance01 1 year ago