NBN double flywheel quick feeding launcher concept

So guys, I spent a few hours making a simple visualization of a famous FRC 2012 double wheel launcher design, and here it is. The concept is:

Double flywheel launcher, angle is locked down
Two flywheels chained together, eliminate inaccuracy issue
Quick feeding tray crank up firing rate

The design challenge is to make sure the ball gets smoothly and easily grabbed by flywheels from both feeding directions. Which takes some design/experimenting with this direct-feeding design.


Any thoughts, comments, questions, criticism, please leave them here. I really really need to study my AP exams… :stuck_out_tongue:
initial launcher prototyping.JPG

Actually teams in FRC during the 2012 season went with a single wheel shooter where the ball traveled around the wheel and adjusted the angle with a moveable backing. Most teams didnt go with the two wheel design because of how uncosistant the accuracy of the ball was.

Agreed. But what do you think causes inconsistency? Velocity difference of the flywheels? Would chaining them together eliminate the issue? That’s what I plan to do.

Also, in your opinion, is adjustable angle launcher really needed in NBN? Or can nice base control replace that? Remember VRC is a game of squeezing the max out of limited motor power. You need motors to adjust barrel angles/orientations.

I have seen a few nice dual wheel FRC launchers, and I personally have no way to tell accuracy. But Rebound Rumble needs the spin to make bank shots. Is NBN the same?

Wait, the backing MOVED?

Watching Einstein, I didn’t see a single robot with that mechanism. Or, I didn’t notice if they did. Can you link me to some info on how they did that?

If you watch this you will see the back part, or the aimer of the fly wheel, move up.

That is COOL. I have no idea if we want to use it, but the mechanism is great.


Not sure whether that is necessary or not… but definitely cool.

My thinking is, if you need to regulate speed to get accuracy, you might top that off a bit by controlling launching speed. But in reality everyone is looking for simplicity, accuracy and consistency. Pneumatic two-stage “hood” might be better off for motor always spinning at full power plus two preset distances.

You mentioned how in Rebound Rumbled the spin was used to bank the balls off the backboard. Besides being used to bounce of the backboard, the spin also causes in-air stability. If your two wheels were spinning at the same speed the ball might tend to be thrown in a “knuckle ball” fashion. In the real world spin on projectiles is very important for accuracy. That is just what my guess is. Although the wheel speed could be easily varied with a slightly smaller sprocket if you were to chain the two wheels together, allowing for a backspin shot.

Unlike Rebound Rumble however I do not think NBN will require much backspin for bank shots. The net seems very squishy unlike a backboard, so backspin will most likely not be required.

(BTW: I am on an FRC team that has played rebound rumble)

Can you give us some more insight as to how one may achieve such backspin?

haha hey Harrison,

your talking about achieving backspin with the double wheeled shooter illustrated above correct?

Would there be a more efficient way, I’ve been thinking a double side shooter + a small wheel in the center would be able to do the curving…

I’m not sure what a double side shooter is exactly, if your could elaborate that would be great.

When you are talking about the small wheel in the center I believe you are referring to a Rebound Rumble Style shooter, correct?

Have 2 siderollers 1 on each side that account for the actual launching, and a centralized wheel like a RR shooter that compensates for lift.

If I understand correctly this shooter would contain 3 wheels. While i think you could make this work I think simplicity is the key factor for this game. What you gain from simplicity is a more consistent system. Also it can save space and motors which are also key.

If your look at FRC 2014 team 254 won with a beautifully simplistic fly wheel shooter. I think a fly wheel shooter with two or one wheels is going to be the money maker in this game.

Back-spin produces in-air stability. Very helpful information. I will need to do a lot of research on that.

Also, i have been thinking the issue with the design concept-- the balls cannot efficiently be gripped in the center cavity and delivered to the position at which the flywheels would grab them. Maybe a simple pneumatic mechanism would solve this issue. Will update further CAD.