> For the complete documentation index, see [llms.txt](https://docs.wcrobotics.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.wcrobotics.org/engineering/2021/ball-shooter.md). # Ball Shooter An adjustable ball-shooting prototype. #### Purpose: * To explore shooter design concepts in FRC. * To develop an adjustable shooter prototype that can be modified for different game pieces. ## V1: Double Shaft Configuration ![6032 Adjustable Shooter Prototype - Double Flywheel Configuration](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MUZk9k5_JWDZgse4ug1%2F-MUaVYfULkCsJaw_FaQ3%2FScreen%20Shot%202021-02-27%20at%209.38.34%20PM.png?alt=media\&token=bc8780c4-6c63-4e6e-9ec6-12d7c872a01e) #### Design Notes: * 80/20 structure is rigid and adjustable. * Bearings and motors mounted to frame with 3D printed brackets (modified [HYPEBlocks](/training/prototyping.md#hypeblocks)). * Large Colson wheels (4" x 2") will hopefully provide grip and sufficient angular momentum. Wheels can be easily swapped out. * Falcon 500's with a CIM Mount, 1:1 VersaPlanetary * 1/2" Hex VP output with shaft coupler (shown) ***Or*** * VP Universal Female Output with female 1/2" Hex adapter * Adjust wheel speed with [servo testers](/training/prototyping.md#frc-motor-testing-with-pwm-generator). Slower on top and faster on bottom should increase the angle of release and give it some backspin. * **Consider adding side guards and a feeder ramp (wood, lexan, cardboard, ...) for safety and so balls are fed in a consistent manner.** * This could be modified as a hooded shooter, and modified for different sized game pieces. * Access the[ Onshape document](https://cad.onshape.com/documents/1ea891045bee623ade3562f1/w/f7bb77c6e571866b071d4888/e/c63cb184484a007dab23641f) for more details. ![Sketch & Cut List](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MVRudauiiFx19-Cs9MC%2F-MVbFPegEVeuEvwCoaxv%2F6032_Adjustable_Shooter_CutList.png?alt=media\&token=0453949b-6f23-493f-adb6-d911d0784bde) #### 3/23/2021 ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MVsJPTRitznR2Bee6AP%2F-MWUVf51ZMukECGUYC2S%2FdoubleWheel%20-%201.jpeg?alt=media\&token=2217ec2b-4038-4a66-89ae-853450a408b3) * When mounting anything to a Falcon 500 motor, you need to use very short screws. 0.5" is too long because it will bind with the motor internally. * **Use #10-32 SHCS, 0.375" long to mount a CIM adapter to a Falcon.** #### 3/24/2021 ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MWUd8hPYjip8GpIY46D%2F-MWZeDO8aNvxH8-HWg9V%2FDoubleWheelIR%20-%201.gif?alt=media\&token=ee3c4967-405c-4dba-810e-5c3dc47c0f49) * Proof of concept * Next steps: * Adjust wheel speeds to "dial in" on a target and evaluate consistency. * Consider adding [flywheels](https://www.swervedrivespecialties.com/collections/flywheels/products/4-inch-brass-flywheel) to shafts, see if that impacts consistency & range. #### 3/26/2021 ![We added brass flywheels](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MWixCkyMsNneguknt6Z%2F-MWixafcq5SgUpkAXyOu%2FDouble_with_flywheel%20-%202.jpeg?alt=media\&token=12dd5a0a-f33a-4475-b5ee-84f96dd2d8fe) ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MWixCkyMsNneguknt6Z%2F-MWiySBL5KHNuGe6MHZn%2FDouble_with_flywheel_gif.gif?alt=media\&token=5a5901c5-35b3-43db-87de-db744515a05d) * The flywheels gave us a more consistent shot when sending many balls in succession. * Students adjusted shaft speeds to aim for a specific point on the wall. They started with slow shaft speeds and increased the speed of each motor one at a time, dialing in on the target. * Next Steps: * Integrate this mechanism onto a robot. * Work on ball intake. * Work on ball storage & how to feed them into the shooter. #### 4/15/2021 ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MYGjZdxkThACixxTH1I%2F-MYKxN36jeMmlBM4u6AF%2FIntegrated-Shooter.gif?alt=media\&token=01cb8505-cb4c-484d-8030-098aa8828242) ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MYGjZdxkThACixxTH1I%2F-MYKxUy0NsFQl4LlTmja%2FIntegrated-Shooter%20-%203.jpeg?alt=media\&token=4b6cbe73-1708-4445-b807-06228356efae) * Integrated the Shooter onto a prototype robot. * Feeder mechanism supplies balls to the shooter wheels. * Already have some backspin before entering the shooter - this is good. * Next Steps: * Continue to "work backwards" & think about how balls can be fed into the feeder mechanism. Maybe from the front of the robot, or maybe behind the wheels. ## V2: Hooded Configuration ![6032 Adjustable Shooter Prototype - Hooded Shooter Configuration](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MUcti1Zy1IksdMGi_ZY%2F-MUeWNN9gsu1XUgBeUi2%2FScreen%20Shot%202021-02-28%20at%204.20.54%20PM.png?alt=media\&token=fb8dc5f5-827f-40af-8250-87290f905d3c) #### Design Notes: * Similar to the Double Flywheel version above, modified by removing one shaft and replacing it with a hood. * May need to use second motor and/or speed it up with a belt & pulleys. * Insert dowel rods in holes or use long standoffs/churro/thunderhex. Fasten a flexible polycarbonate sheet to the dowel rods to create a smooth hood. * Adjust compression and release angle by using different holes for the dowel rods. ## Inspiration #### Team 5013 Trobots {% embed url="" %} This shooter uses two sets of wheels. You can control release angle by adjusting the speed of the top and bottom wheels. #### Ri3D Team 1.0 {% embed url="" %} Here is a prototype version of a similar idea to team 5013. #### 3847 Spectrum [This concept](https://docs.google.com/document/d/15Pi6qQt_WJx4HBOPCWf5xZ7k2VCiwzgDzia0TgsRank/edit?usp=sharing) is made with Protopipe. ![From the Spectrum Protopipe documentation](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MSYjACM-Ljr_lTVlB_I%2F-MSZGDAIdxFfGy6DeVC9%2FScreen%20Shot%202021-02-02%20at%202.42.32%20PM.png?alt=media\&token=2ca9d3bc-2e86-4997-b67c-464ab559789a) #### #### 2706 {% embed url="" %} This design features a simple over the bumper intake, low profile, and shooter with a non-adjustable hood. #### 5712 Gray Matter Robotics ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MUckakuuiLh8BBwp1IU%2F-MUctaeQkNSXDO1kqTvs%2FGrayMatterRobotics.jpg?alt=media\&token=a62f7a31-a68f-4718-8ba7-f66917df3343) #### 1690 Orbit {% embed url="" %} This team was able to adjust the angle of their entire shooter in order to adjust the release angle. #### 6328 Littleton Robotics Team 6328 has an amazing shooter, with [full CAD](https://littletonrobotics.org/week-6/) available in Onshape. We can learn a lot from these details in CAD. ![](https://3143031572-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MSTlPxAkbXFCKT1jTKl%2F-MTwfL3MDOruPVEs99XJ%2F-MTwicb4EnxqtWW0UWAA%2F6328.png?alt=media\&token=9a31b27f-b45d-423d-9be1-b3b072ad8e06)