FAW (Floating Axle Whipper) Trebuchet

First test shots at the Bryce Ski resort on the driving range and at the library/airport. 2x2 and 2x4 frame held together with 1/4" lag screws. The 5/8" threaded rod axle with pvc pipe ends is attached to (2) heavy duty drawer slides using pipe hangers and plywood blocks. No trigger yet, so I drop the throwing arm (TA) and CW hanger by hand. This frame was also used for my FAKA trebuchet. The tracks were raised for TA clearance at the bottom. TA can be used in 4:1, 5:1 and 7:1 beam ratios. TA is made from a birch dowel, 1/4" plywood and a 2x4. Projectile in this video is a tennis ball which rests in an adjustable carriage on top of the throwing arm allowing different sling lengths to be used with different weight projectiles or for tuning. Longest tennis ball shot has been around 210 feet using 20 lbs. of counterweight.

Category:

Science & Technology

Tags:

• FAW
• Whipper
• Trebuchet
• Catapult

[ketmaniac]

Nice machine. Would you tell me what height the 20lb CW drops through? Have you any idea of the take-off velocity?

[CBasement]

@ketmaniac Thanks. The weight shown in the video was 10 lbs., but a one time attempt at 20 lbs. was at the same height of around 60 inches. It broke the drawer slides. I have no idea of velocity. The angle was very low maybe in the 20 degree range. More height and it would have gone further.

[CBasement]

The tennis ball hurling one in the video is about 4 feet high at the axle with a throwing arm around 51" total length IIRC. I built it that size so I could transport it by myself. Are you thinking of building one?

[desel09]

how big would you build the frame if you were hurling a tennis ball?

[CBasement]

@desel09 Sorry to be answering so late. Not much bigger. Tennis balls are very poor fliers (projectiles) and are good for situations when you don't want to break anything in your neighborhood but want to test your machine safely.

[parker5013]

do u know where i could get plans or could u send me some?

[CBasement]

No plans available. Lost all my drawing files when my hard drive crashed earlier this year.

[flanker1498]

hay my name is bryce ha

[drewnickel]

try more dense projectiles, steel, lead, tungsten, copper, or any kind of metal really will make that 20lb counterweight waste less energy. you could probably mess with the sling length and use a 4oz lead ball with the same weight and because it hass less air resistance you could top 300 or 400ft

[CBasement]

Thanks. Check my other FAT/F2K videos of the trebuchet you're describing.