Difference between revisions of "DEWBOT XIII Shooter"
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==Shooter== | ==Shooter== | ||
| + | The shooter is a basic single-wheel shooter. While simple, this mechanism went through an enormous amount of testing and development, including multiple prototypes, the last few being CNC-produced. | ||
| + | |||
| + | Some key learnings: | ||
| + | * A flywheel reduces the magnitude of speed reduction while shooting, but not recovery time | ||
| + | * More power reduces speed recovery time | ||
| + | * Holes in balls (fuel) interacting randomly with thin shooter rails randomly throw off ball trajectory | ||
| + | * 6 inch wheels provide more consistency than 4 inch | ||
| + | * 2 inch wide wheels provide more consistency than 1 inch wide | ||
| + | * Printed guides expanding the ball contact area from narrow rails to >1/3<sup>rd</sup> circumference, thereby improving shooting consistency | ||
| + | |||
| + | Key design features: | ||
| + | * PID controlled wheel speed | ||
| + | * 3:1 reduction via 1-stage versaplanetary gearbox | ||
| + | * Up to (3) 775 Pro drive motors | ||
| + | * Adjustable shooting trajectory 60-85° from horizontal - adjustment via a quarter scale (large) servo. The servo drives a 14T gear (20 DP - 14° contact angle) which drives an 84T half gear on the trajectory hood. A 180° rotation of the servo rotates the trajectory hood by 30°. | ||
| + | * Trajectory hood rotates co-axially with shooter wheel axle. | ||
| + | |||
| + | As of FRC Championship, we seem to have a shooter capable of shooting ~6 balls/s with good accuracy. We, however, are not able to feed this shooter consistently at this rate. As a result, shooting rate is erratic. | ||
<gallery widths=250 heights=250 perrow=3> | <gallery widths=250 heights=250 perrow=3> | ||
| Line 13: | Line 31: | ||
image:DB13_170114-12.jpg|next prototype | image:DB13_170114-12.jpg|next prototype | ||
image:DB13_170114-13.jpg| | image:DB13_170114-13.jpg| | ||
| − | image:DB13_shooter_170119.jpg|early CAD | + | image:DB13_shooter_170119.jpg|early CAD with CIM drive |
image:DB13_shooter_170121.jpg|Double shooter CAD | image:DB13_shooter_170121.jpg|Double shooter CAD | ||
image:DB13_170121-4.jpg|Aashay & Gary | image:DB13_170121-4.jpg|Aashay & Gary | ||
| Line 23: | Line 41: | ||
image:DB13_170122-3.jpg| | image:DB13_170122-3.jpg| | ||
image:DB13_170122-5.jpg| | image:DB13_170122-5.jpg| | ||
| − | image:DB13_shooter_170126.jpg|CAD of duplex shooter | + | image:DB13_shooter_170126.jpg|CAD of duplex shooter - now using 775 Pro motor w/ 3:1 reduction |
image:DB13_170128-1.jpg|Shooter frame | image:DB13_170128-1.jpg|Shooter frame | ||
image:DB13_170129-6.jpg| | image:DB13_170129-6.jpg| | ||
image:DB13_170129-7.jpg| | image:DB13_170129-7.jpg| | ||
image:DB13_170203-1.jpg|CAD showing early elevation adjustment hood | image:DB13_170203-1.jpg|CAD showing early elevation adjustment hood | ||
| − | image:DB13_170203-17.jpg| | + | image:DB13_170203-17.jpg|Shooter with double 775 Pro drive |
image:DB13_170204-7.jpg| | image:DB13_170204-7.jpg| | ||
image:DB13_shooter_170208.jpg|CAD with revised elevation hood | image:DB13_shooter_170208.jpg|CAD with revised elevation hood | ||
| − | image:DB13_170212-2.jpg| | + | image:DB13_170212-2.jpg|14T drive gears for angle adjustment |
| − | image:DB13_170212-3.jpg| | + | image:DB13_170212-3.jpg|84T gear being machined for shooter angle adjustment |
| − | image:DB13_170212-7.jpg| | + | image:DB13_170212-7.jpg|Shooter testing with 6 inch wheels |
| − | image:DB13_170213-2.jpg| | + | image:DB13_170213-2.jpg|Half 84T gear for elevation adjustment |
image:DB13_170219-7.jpg|Shooter mounted | image:DB13_170219-7.jpg|Shooter mounted | ||
| + | image:1640 2017 Shooter.png|Shooter with printed guides in place | ||
| + | image:DB13_shooter-5.jpg|6 inch flywheel | ||
| + | image:DB13_shooter-6.jpg|3-motor (750 Pro) shooter gearbox | ||
| + | image:DB13_shooter-9.jpg|3-motor shooter w/ 6" flywheel in ''deux'' | ||
</gallery> | </gallery> | ||
==Feeder== | ==Feeder== | ||
| + | <gallery widths=250 heights=250 perrow=3> | ||
| + | image:DB13_170118-4.jpg|Hopper tests | ||
| + | image:DB13_170121-5.jpg|prototype | ||
| + | image:DB13_170121-8.jpg|testing | ||
| + | image:DB13_170124-2.jpg| | ||
| + | image:DB13_170124-3.jpg| | ||
| + | image:DB13_170125-2.jpg| | ||
| + | image:DB13_170126-3.jpg| | ||
| + | image:DB13_170128-6.jpg| | ||
| + | image:DB13_170128-14.jpg|First rotor-type prototype | ||
| + | image:DB13_170128-17.jpg| | ||
| + | image:DB13_170128-18.jpg| | ||
| + | image:DB13_170131-1.jpg|Rotors | ||
| + | image:DB13_170210-1.jpg| | ||
| + | image:DB13_170218-40.jpg| | ||
| + | image:DB13_170219-11.jpg| | ||
| + | image:DB13_170219-14.jpg| | ||
| + | image:DB13_170220-22.jpg| | ||
| + | </gallery> | ||
==Ball Pickup== | ==Ball Pickup== | ||
Latest revision as of 10:30, 11 May 2017
It had been the team's intention and strategy for DEWBOT XIII to be a high-performance shooter (together with good rear running capabilities and a fast, reliable climb). Alas, we did not accomplish the critical shooting goal. Our shooter was definitely middling. While very consistent in its shooting and capable of shooting consistently at up to 6 balls/s, feed issues limited us to an average 2.5 balls/s. In addition, while shooter elevation and wheel speed are adjustable,we had a limited number of pre-set shooting solutions and limited objective data on which to base such solutions.
The Shooter System comprises several interacting components:
- Shooter
- Feeder
- Ball Pickup
- Hopper
Contents
Shooter
The shooter is a basic single-wheel shooter. While simple, this mechanism went through an enormous amount of testing and development, including multiple prototypes, the last few being CNC-produced.
Some key learnings:
- A flywheel reduces the magnitude of speed reduction while shooting, but not recovery time
- More power reduces speed recovery time
- Holes in balls (fuel) interacting randomly with thin shooter rails randomly throw off ball trajectory
- 6 inch wheels provide more consistency than 4 inch
- 2 inch wide wheels provide more consistency than 1 inch wide
- Printed guides expanding the ball contact area from narrow rails to >1/3rd circumference, thereby improving shooting consistency
Key design features:
- PID controlled wheel speed
- 3:1 reduction via 1-stage versaplanetary gearbox
- Up to (3) 775 Pro drive motors
- Adjustable shooting trajectory 60-85° from horizontal - adjustment via a quarter scale (large) servo. The servo drives a 14T gear (20 DP - 14° contact angle) which drives an 84T half gear on the trajectory hood. A 180° rotation of the servo rotates the trajectory hood by 30°.
- Trajectory hood rotates co-axially with shooter wheel axle.
As of FRC Championship, we seem to have a shooter capable of shooting ~6 balls/s with good accuracy. We, however, are not able to feed this shooter consistently at this rate. As a result, shooting rate is erratic.
early prototype
next prototype
early CAD with CIM drive
Double shooter CAD
Aashay & Gary
CNC Router
Flywheel
CAD of duplex shooter - now using 775 Pro motor w/ 3:1 reduction
Shooter frame
CAD showing early elevation adjustment hood
Shooter with double 775 Pro drive
CAD with revised elevation hood
14T drive gears for angle adjustment
84T gear being machined for shooter angle adjustment
Shooter testing with 6 inch wheels
Half 84T gear for elevation adjustment
Shooter mounted
Shooter with printed guides in place
6 inch flywheel
3-motor (750 Pro) shooter gearbox
3-motor shooter w/ 6" flywheel in deux
Feeder
Hopper tests
prototype
testing
First rotor-type prototype
Rotors
