pic: Prototype Iteration 1

Based off of some fairly specific math, here is the first iteration of kicker design I’ve come up with so far. It’s roughly 9" tall, and 1/4" thick. It’s 0.25 lbs, though that’s not an issue yet. Two of these will have standoffs in between them and be driven by either surgical tubing or springs, adjustable via the holes at the top. It makes contact with the ball at the bottom. I haven’t created all of the standoff holes yet since I’d like feedback.

I cannot do a FEA on this, so where would you guys/gals estimate its greatest structural weaknesses are? Are there any overall shape improvements that could strengthen it?

In general, straight members are stronger than curved members, right?

but they don’t look so nice :slight_smile:

Does the curve provide any significant change in the parabola? Creates more of a wedge, I suppose.

Since the radius from the axis of rotation to the hole at the bottom is constant, the curve itself doesn’t effect the end trajectory.

The idea of the outer curve is that the force of impact of the spring has a way to travel directly to the bottom without it all going directly through the bearing. We haven’t figured out exactly how much force will be necessary, yet I’d like to plan to not break the kicker at all. Due to spacial constraints, the top of the kicker cannot be in line with the bottom of the kicker, thus the off angle (~15 degrees) and the curve.

We’ll test this out over the next couple of days and see what happens I guess.

Here is a Soviet-style, brute force suggestion :slight_smile:

I would guess you could make the kicker arm out of ugly extruded aluminum that gets beefed up a bit where the axle goes through it and consequently not have to do any fancy machining. Extruded parts like the 8020 products seem plenty stiff enough.

To take much of the lateral force off of the axle, either support the axle right next to the kicker arms; or put a round bulge concentric with the axle into the kicker arm, and use rollers outside that bulge to cradle and support the arm/axle combination.

That’s the proof of concept we did last week; now we’re on to the actual design that will be implemented on the bot. There are spacial constraints that prevent us from using a straight bar.

In Soviet Rrrussia, concept, prove YOU!:ahh: