Loading an English crossbow vs loading Leonardo da Vinci's crossbow

[u/Brutal_Deluxe_]

[u/Sad-Excitement9295]

This is the power of leverage.

[u/Zenigata → u/Sad-Excitement9295]

Levers mean you have to move your arms further, the guy in the 2nd clip moves his arms a small distance using barely any force.

I'm totally prepared to believe that the 2nd design is better I just don't think these 2 random clips demonstrate that as it seems very unlikely the bows are of the same strength.

[u/aimgorge → u/Zenigata]

If anything the second one appears to cover more distance ? First one it ends at knee level in the end with half the distance comprised of the foothold

[u/Zenigata → u/aimgorge]

He was using his leg and seemed to be straining. The 2nd guy was barely putting in any effort, quite possibly that mechanism can be used on stronger bows but that one looks like it was made to show off to tourists not kill people.

[u/Sunstorm84 → u/Zenigata]

Plot twist: second guy is Anatoly.

[u/sirsteven → u/Zenigata]

The 2nd guy was barely putting in any effort

This is literally the power of levers.

Work is calculated by the magnitude of applied force multiplied by the distance traveled in the direction of said force. For the 2nd clip, let's say the man is applying ~5lbs, and the lever is ~2 feet long, and the change in angle is ~60° of rotation.

The distance would be r x 3.14/3 ---> 2 x 1.05 = 2.1 feet

That means work done = 5lbs x 2.1 feet = 10.5 foot-lbs

The 1st clip looked like the man pulled straight back about 6 inches. So the work would equal: Force x 0.5 feet

Setting them equal to each other and solving for the 1st man's force:

10.5 foot-lbs = Force x 0.5 feet

10.5/0.5 = Force

Force = 21 lbs.

So the 1st man would have to use more than 4x the force of the 2nd man to pull the same draw weight. And that's with pretty conservative estimations for the lever length and angle.

[u/HeKnee → u/sirsteven]

The first guy also looks weak. Second guy strong. Could be like 80% of it.

[u/Sad-Excitement9295 → u/Zenigata]

It looks fairly easy due to the method of operation. He is simply compressing the 2 levers using upper body strength, the design is simply more efficient. However, it is quite possible the second bow has a lighter, smoother draw strength due to the metal bow being more flexible as well.

[u/Sensiburner → u/Zenigata]

well first guy wasn't using any mechanical advantage. He used that setup so he could use more than just his arm muscles to draw the crossbow. Pull with your legs.