pic: 604's Arm

Quick Fix:

Buy a piece of channel with a 1" slot and 1/8" wall (they sell it at Allen Steel and other suppliers in the Bay Area).

Unbend your arm and press-fit the channel onto it. You won’t even need any bolts. It will be so tight it won’t ever come off.

That should get you into the first practice matches:D

Yea same here. That 290-2 match may not have been such a great idea to start the day off :wink: haha, but hey it was the highest score at the regional. it was great playing with you guys…

Yet again, you guys were a great alliance, both 604 and 668. It is too bad about your arm. At least you only need to replace the tubing. And now you can take off the steel and add a beefier arm. Good luck.

Also note exactly where it failed - right where the hole on the top & bottom starts. As you get closer to the fixed point (the end held in position) the force on the metal gets higher very quickly given a small force at the free end.

The hole is a “stress concentrator” - the ‘lines’ of stress (or force) cannot ‘flow’ through the hole, they must go through a solid, so all the stresses focused at the end of the hole, and that being a weaker point, it failed.

As stated, it can be calculated with some reasonable assumptions. This is called “engineering”

Of course, even with double the arm, there can always be a hit that’ll bend it. I, too, hope that your repair efforst go smoothly and you whomp them all in competition…

Don