Boulder inconsistency issue

[waialua359]

Teams are lucky that they dont have to worry about limiting muzzle velocity like in 2006.
I have already seen some pretty fast (and dangerous) linear shooters, but at the same time can limit the effects that boulder inconsistencies can cause.
Potential inconsistency is the primary reason we went with a catapult design this season.

[Arhowk]

Originally Posted by quillford

We're running them with versaplanetaries 1:1 just for the ease of mounting. Are you shooting in the high goal with that much reduction?

Oh my bad I thought you were having intake issues. We use a 1:1 fly wheel shooter running from a CIM motor. We have a decent bit of aided compression with that as well (the shot goes through the intake motor which we drive forward when we shoot to get a cleaner shot). (That intake motor is the one running 30:1). Don't know how much ball difference there was at Lansing but we got first in qualifications so we did something right .

[wilsonmw04]

Originally Posted by quillford

Throughout most of build season we tested with only one boulder and tuned everything based off that one boulder, but as soon as we got a new one we noticed that it shot completely differently.

Welcome to the lessons of Rebound Rumble. After playing with the scoring pieces for a few minutes, we ruled wheeled shooters out. The balls were just too wonky. It really doesn't matter what motors you use. The inconsistencies will persist.

[Deke]

There are ways to shoot the ball where the inconsistencies from ball to ball don't affect the trajectory. Keep playing with grip, speed, ball centering, and compression and I'm sure you'll find success with a wheeled shooter.

[orangemoore]

Reduction and gearbox choice offers no help when talking about this unless you include wheels sizes as well.

How am I going to know if you use 20" wheels for 2" wheels.

The only information I have is RPM

[Hitchhiker 42]

Just as another approach (instead of the mechanical side), here's a programming side:

Tune a PID control with a feedforward on the shooter motors. For us, this significantly decreased ball consistency problems with high shots. Although the ball is shot out really fast, there is enough time to somewhat correct the RPM back to your set RPM as the shooter is slowed by the ball going through it.

[Sperkowsky]

Boulder inconsistency really really hurt our team. Our issue wasn't accuracy related and we were testing with 8 different boulders throughout the season. Basically what was wrong was our pneumatic indexer. The indexer had a 3/4" stroke which worked fine for all 8 of our boulders. We even went to the Suffield Shakedown and played half the day without having one issue. Then what continued to happen was the ball would come in contact with the wheels rendering us useless. We tried switching to our next smallest wheels 2 7/8" BB wheels which worked for a few Matches until we met a boulder that was too small. Then the indexer couldn't hit the ball into the wheels. All in all it was not fun to try to figure out what kind of Boulders were on the field. We have already developed a pretty simple fix (longer cylinder farther back) but it's a little late. Luckily we have 3 off season competitions to play with it.

[Ninjastahr]

My team has the same problem (we were forced to low goal for all of the Iowa Regional). We compressed the ball more, and now it works much better with different balls. We use two 2" orange BaneBots wheels with a cylindrical piece of metal between them on each side (the piece of metal makes it so the wheels don't stall when the ball hits the wheels).

[Ether]

Originally Posted by Ninjastahr

We use two 2" orange BaneBots wheels with a cylindrical piece of metal between them on each side (the piece of metal makes it so the wheels don't stall when the ball hits the wheels).

This is a case where a picture would be worth a thousand words.

[Ninjastahr]

Here's a picture.