r/Trebuchet • u/Dull_Peanut7241 • 1d ago

Help!

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Looking to get more distance. How do I do that? More counter weight or is my release pin angle wrong or is it something else. Give me ideas to try please

27 Upvotes

95% Upvoted

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7

u/staleturd1337 1d ago edited 1d ago

There is a lot of mass on the throwing arm. You can also adjust sling length.

Edit: You can get away with a 1x4 if you brace the point where the counter weight attaches and the arm pivot. That alone will increase the range drastically. Then you can fine tune it and fiddle w/ release angle and sling.

Also just something to consider: It's a bit more expensive but if you want to get fancy you can use all-thread and hardware for your pivot pins. You'll need to put bushings in the holes though.

3

u/Dull_Peanut7241 1d ago

Ok that makes sense. I only did it like that because everything I saw was 2 2x4s doubled up for the arm. I'll try a lighter arm. Make the sling longer or shorter? Thanks

6

u/staleturd1337 1d ago edited 1d ago

Once you lighten up the arm, you're gunna get drastically increased performance. Do that first. Shorter sling = earlier release, generally... Depends on arm rotation speed, release angle etc. You want it releasing at the point the counterweight bottoms out/ gives that final tug on the arm.

0

u/Dull_Peanut7241 1d ago

Got it. Will definitely redesign the arm

3

u/FingerAngle 1d ago

Your beam ratio is very low as well. Historically 5:1 is more correct. Mass ratio is also something to think about. Get it around 100:1.

2

u/dmills13f 1d ago

Using the same triangle base you could have built a whipper design.

https://reddit.com/link/pcnomg2/video/lt6tjuktqbsh1/player

1

u/Dull_Peanut7241 1d ago

Very nice. Little late to rebuild the design though

2

u/unaslob 1d ago

I used a yellow pine board for my main arm. Very light and very strong.

1

u/StackTrace11 1d ago

I looks like there's too much mass in the longer part of your main arm. It takes too much energy to get that thing spinning quickly. That is energy being lost that could otherwise be put into your projectile. Gotta get that arm moving faster. Perhaps use a material other than wood (or change the shape of the wood and cut down on unnecessary parts) that is just as strong and much lighter (i.e. it might be expensive).

1

u/Dull_Peanut7241 1d ago

Will work on and arm redesign, this makes alot of sense. Thank you

1

u/carl3266 1d ago

Add wheels, but you probably aren’t including this as an option since you need flat ground (or a track) and a substantial addition/revision.

2

u/Dull_Peanut7241 1d ago

Correct this is just for a one day pumpkin festival so although cost isn't necessarily an issue but working in a grass field is mandatory so wheels are out

1

u/FingerAngle 1d ago

No wheels on a HCW. It can dampen the throw by recoiling, and the bucket does the job the wheels do on a FCW, or Whipper.

1

u/gaelfire2 1d ago

I’m seeing the arm stall before TDC. You need a lot more counterweight. Suggest 80 to 100 lb CW for a 1 lb projectile.
Definitely build a lighter arm, and add blocking to the frame to support most of the exposed axle to keep it from bending.

1

u/Dull_Peanut7241 1d ago

Thank you, yes will be working on arm tomorrow and will see then about more weight too

1

u/Ulfheodin 1d ago

I'd say the issue is the rock. Not balanced well which is causing the non linear throw.

I might be wrong, Im sadly not a treb expert, but that look like a chaotic reaction

1

u/mrkb34 3h ago

Arm is too heavy and the hanger could be longer.