Whipper Trubuchet - Small and Full Scale

0:01 Intro
2:00 Small Scale Version
4:24 Building Full Scale
11:27 First Shots
11:52 Analysis, How to Optimize
18:32 Minor Changes
20:01 Sling Fail, Analysis
21:29 Good, not perfect
21:42 Analysis
22:47 Longer Sling, Success
26:38 Launches!
Trebuchet Designed by Tom Stanton
/ tomstantonengineering
Audio courtesy www.bensound.com

[@prettybusyinc]

Excellent Work Brian. Thank you I learned a about trubuchet.

[@throwing_things7773]

Interesting video.

[@DusanPavlicek78]

Showing your analysis in the software is priceless.

[@briangray5067]

Thanks! I love data! :)

[@thomasrosenthal1738]

Pretty nice analysis of what goes into a good throw. It's strange to me seeing the high-tech production since I started with salvaged wood cut with a few tools on a folding workbench.
One thing with the larger version, your cocking angle isn't as steep as on the smaller version.
The videography is excellent. I'm trying, unsuccessfully so far, to figure out why you aren't getting am stall. Your arm isn't too heavy and the tennis ball likewise isn't massive for the counterweight.

[@briangray5067]

Thanks for the comments!

[@sman1960]

This is totally awesome, Excellent build. How's the arm holding up? I think I saw a bit of flex in the arm in your slow motion videos. Would a stiffer arm help for more distance?

[@briangray5067]

Thanks! And yes, it also appears to me that the arm slightly flexes. I'm sure that making it more rigid would lead to more energy being transferred to the projectile. I have considered taking a piece of aluminum U-channel and attaching it to the arm for better rigidity.

[@sman1960]

@@briangray5067 If you did the arm again and glued a piece of metal between the two parts it might make it a lot stiffer...

[@briangray5067]

​@@sman1960 Yeah, I think that's the best way. But if I try this, I might go with a U-channel attached to the arm just to test the theory before committing to fabrication of a laminated piece, as this will be a bit more time consuming. Thanks!

[@briangoulet8039]

You could reinforce the existing arm with fiberglass and resin, potentially? Then you wouldn’t need to fabricate anything new but it might give it more rigidity…

[@briangray5067]

@@briangoulet8039 Yeah not a bad idea! Thanks!

[@baileesthilaire]

Hey Brian, for a school project in engineering we are building a trebuchet and competing against our classmates. Our group was really interested in yours, and we were wondering if you had blueprints/plans that we could look at of your final project.

[@briangray5067]

This design was from Tom Stanton. Look up his YT channel, and look at his trubechet videos. I don't remember exactly which trebuchet video it is, but he supplies his CAD file within the description of one of those videos.

[@bobaustin4203]

I can understand putting wheels on these units for transport, but if you were to lock the wheels, wouldn't that provide more energy to the propulsion of the projectile?
RA

[@briangray5067]

Actually, the wheels are better for transferring energy to the projectile. You'll notice that the wheels allow the trebuchet to move in the throw. This allows the weight to fall more of a straight path down rather than following a curved path down. This helps to better synchronize the arm stall, the weight stall, and the projectile release to each other. Getting all three of these moments synchronized delivers more energy to the projectile than without wheels. Tom Stanton explains this very in-depth here. th-cam.com/video/KpFTyE-wiNo/w-d-xo.htmlsi=--AVpdOas1U_d25z

[@shyonemami7388]

Did you use bearings for the smaller version?

[@briangray5067]

Yes, both used bearings. Thanks!

[@ryanhaggerty5251]

Hey there Brian my name is Ryan and I would like to build the small scale model this and I was wondering if you could share the plans with me.

[@ryanhaggerty5251]

I would just like to say what an amazing video.

[@briangray5067]

Thanks Ryan! You can get the plans from Tom Stanton's channel. I can't remember exactly which video, but it's one of his trebuchet videos. He links the files in the video description on one of those videos. That will get you full scale plans, and then you can just scale them down to whatever you like.

[@ryanhaggerty5251]

@@briangray5067 Ok than you

[@lyricalfamous4301]

Hey dude can you help me for my physics project

[@FingerAngle]

He got his idea from me

[@FingerAngle]

I've been building whippers for 9 years. This is the 1st version of the "curved" hanger. th-cam.com/video/4vOs3j6ve5M/w-d-xo.html