From having heard about all the different ways teams improved their shooting with damaged balls and their inner goal accuracy (from the giant shooter wheel of 2481 to the additional flywheel on the ends of 4414 & others hoods) - what did your team find to be helpful in:
Mitigating the effects of damaged balls?
Increasing accuracy in the inner port?
These could be complex, like the methods mentioned above, or simpler, like choosing to shoot from closer up because you found you made a greater % of your shots in the inner goal that way.
Data, pictures of shooters, and video of it functioning would be excellent!
Do you mean this as just a general ācompress the ball moreā or a design similar to 3940ās, where the compression starts at some value and ends at some higher value?
In terms of compression, Iāve seen successful shooters with 1-2.5 inches of compression. 1.5inches is my favorite. when i say increasing compression over time is just increasing the compression of the ball over the path, like from storage all the way to the end of the shot.
Something for us that decreased accuracy of any sort was larger shooter wheel - 6" was less accurate in early testing than 4" (at the same RPM) at the cost of less height and range.
I really want to get back in the shop and get real data.
Interim, models are cool and my model says:
If you want to decrease exit velocity sensitivity to ball stiffness or grip, the objective is to make the ball stop slipping; the ball needs to reach a steady-state velocity before it exits. You can accomplish this with
more grip (both of the wheel, and the hood, though the hood is usually sufficient)
more travel distance
more compression (but it doesnāt do as much as I expected)
increase wheel diameter (even if you maintain the same surface speedā¦ the increased diameter means less centripetal force that lifts the ball off of the flywheel. Wacky, right?)
reduce wheel RPM (this may decrease your shot power if youāre in the āslip zoneā, but it should increase accuracy)
If you want to decrease exit velocity sensitivity to mass
increase wheel momentum
decrease wheel RPM (again, may negatively impact shot power)
From a rough analysis we understood most of this (even if we couldnāt put numbers to it) so we built accordingly with some pretty substantial travel distance and wheel diameter. Things were looking grim by the end of GSD though so we started looking for better wheels to increase grip, and we think we found the right setā¦ ah, what could have been (what will be?).
Other miscellanea beyond āmake shooter go thunk thunkā
Mount it rigid otherwise its worthless
Have a non-rocking drivebase otherwise its worthless (this is what motivated us to run a 2+2ā¦ you could definitely do a 6wd drop center with the weight biased properly)
Level your turret, if you have one. We noticed that we would shoot completely different forwards than backwards until we shimmed the ring. Granted, weāre not CNC-ing everything, but even then, tolerance stacks can be enough to warrant adjustment.
(more of a hunch than anything) Also for turrets, feed the balls dead center, with no asymmetry, with as minimal compression as possible, and straight up (no rolling). (Minimize the input variation as a function of turret angle).
Dual wheel shooters are weirder to understand.
Hopefully when we get back to the shop we can correlate test data to a model
Increasing the contact distance between the shooter wheel and balls.
If you want to keep your shooter smaller, you can try to add a pre-accelerator wheel. (For accelerating the ball nicely)
Donāt use the compliant wheels because the ball is already plenty compliant on its own. You can lose a lot of energy because of compliant wheels friction.
Getting flywheel speed control down for potential speed losses while shooting multiple balls.
Interesting. We actually had our shooter geared up by about 1::2. We had 3 Neos with an adjustable hood. We found our accuracy to be better with higher RPM. We actually shot at about 10,000RPM. At that speed we found the flatter arc of the shot made things much more repeatable even with balls of varying quality.
This also gets at something true: your arc also matters. All of my previous points have to do with creating a consistent ball state after the shooter- how your trajectory is shaped impacts how the error in ball state gets magnified.
The straighter the arc the less sensitive youāll be to variations in exit velocity.
The more perpendicular your trajectory intersects the goal (e.g. your trajectory āapexesā when it hits the goal), the less sensitive youāll be to variations in distance from target.
The more of a ālobā you have, the less power required to make the shot (so the laser shot comes at a priceā¦ which you know already ).
If you have any gears in your shooter (not gearboxes. Gears.), make sure that the power cells have absolutely no way to get in contact with them. Otherwise, this happens.
We tried 4in orange bane bots wheels and Colsons and found that the bane bot wheels ended up in a further and more consistent shot and they also help with the power cell longevity
