Thursday, January 16, 2020

2020 Day 13: Prototypes are working

Shooter

The shooter prototype was updated with a more rigid hood and basic velocity control on the NEO motors. It's shooting with 2 NEOs powering a 6" wheel 1:1 at 5000 RPM and a 4in accelerator wheel powered by 1 NEO 1:1 at 5000RPM. We plan to update the shooter to gear the main flywheel up so the NEOs have more power head room to maintain an RPM of around 5000. We also may test powering the accelerator wheel off the same two NEOs that are powering the main fly wheel.

FullSizeRender

Intake

Our newest intake prototype is meeting all our expectations for an intake. The balls are rapidly moved up into our robot and our new indexer should be able to sort out the 3 wide balls pretty easily in the unlikely case we are intake 3 balls all sitting next to each other.
IMG_20200116_174157369.jpg

VID_20200116_174326864
Video

Indexer

The indexer prototype based on FRC#6135 is working flawlessly. 
IMG_20200116_172706.jpg

Video of it working without intake
IMG_0843
Video

More Pictures and Video of all the systems are available in our photo gallery. 

Spectrum Dead Axle Rollers

The roller setup we have been using in our prototypes are based on a system we developed for our 2019 Cargo intake. We plan to use it again for our Power Cell intake.

The system has 6 parts
  1. 7/8" Aluminum Tubing 
  2. 1.125" ID x 1.25" OD Polycarbonate Tubing
  3. McMaster Tube Connecting Nuts for 7/8" Tube
  4. 7/8" ID x 1.125" OD Needle Bearings
  5. 7/8" Push on Retaining Rings
  6. 3D printed Clamp-On Pulleys

  • The 7/8" tube has the tube connecting nuts (star nuts) pressed into the ends of the length you need to span and is bolted into place on the ends acting as a standoff between two plates. 
  • The needle bearings go in the ends of the polycarbonate tube after you cut it to length. 
  • The push on retaining rings hold the tube and needle bearings in place. 
  • The 3D printed pulley clamps over the polycarbonate tube so it can be driven by a belt. 
  • Any rubber tube of your choice can be applied to the outside of the polycarbonate tube to provide grip on the game pieces. 

IMG_20200116_174426.jpg
IMG_20200116_174430.jpg

Spectrum

2020 Day 12: New intake/indexer Plan

Block Robot Update

The new intake plan, allows for balls to rapidly be brought into the robot with a wide intake, and set quickly into the tower using a powered V similar to prototype videos from FRC#6135FRC#4481 and FRC#95 . We plan to prototype some variations of this idea by adding a central channel for balls to rolls straight down and possibly a powered belt to move balls towards the tower belting as well. We will test various options for the side conveyors/wheels and also speeds and direction changes.
The tray on top of the intake is designed so this robot would be able to load from the human player station with the intake down. That should allow us to intake balls on the ground and then quickly get any remaining needed balls from the loading bay when drive in.
Block Robot 1-16.PNG

When retracted the intake acts as a cage around any balls remaining in the funnel to not allow them to bounce out of the robot as we drive over the boundaries.
Block Robot 1-16 #2.PNG

We have prototypes of these systems under constructed and will post video and photos when they are operational.

Spectrum

Wednesday, January 15, 2020

2020 Day 11: Design Review Week 2

Tuesday = design review day

Here are some of the slides from today's review put together by each of the subsystem lead groups.

Drivetrain week 2.PNG
Intake Week 2.PNG
Intake week 2 #2.PNG
Climber Week 2.PNG
Buddy Climb Week 2.PNG
Shooter Week 2.PNG
Shooter Week 2 #2.PNG
Photo of V2 Prototype using HYPEblocks, hopefully we will have some testing tomorrow. We have to refactor the hood a bit.
IMG_4966.JPG
Controls Week 2.PNG


Spectrum

Tuesday, January 14, 2020

2020 Day 9 & 10

Everybot and Week 6 Robots

This past Sunday, Spectrum was able to attend an event hosted by the Robonauts were Everybot and Week 6 demonstrated game play together. Both robots were very well done for only needing one week to complete.

Takeaways (Some are just confirmations of what we already knew)
  • The outer goal is very large. Week 6 was able to easily manually aim their robot to score consistent shots.
  • Fast low bots may have value in getting up to the RP level of balls but you need to be very quick in getting balls dumped into the goal and quick at intaking balls. Everybot does both very well.
  • The balance even on the wooden switch didn't seem hard to accomplish. A reliable and consistent climb will be incredibly important.
  • Driving across the Dance Floor (rendezvous points) will test how robustly made a lot of robots are. Make sure you test your robot driving over 1" bumps (the kit 2x1 is a good approximation) before coming to your first event. We are going to see a lot of radios, roboRIOs, batteries and other electronics and connectors come loose if they are only zip tied loosely to robots.
IMG_20200112_151907140.jpgIMG_20200112_151909722.jpg

More photos and videos are in our photo gallery.

Shooter Prototype V2

Hopefully will have test shots tomorrow after we make it a little more rigid.
IMG_20200114_003754.jpg

Intake/Indexing

Intake and indexing plans are still up in the air. We are re-investigating an intake similar to 971's from 2012. At first we didn't think it would package nicely but after some other changes to the design we think we can make it fit, but we need to build a better model to make sure it will index the balls fast enough for our robot.

Indexer.PNG


Robots that inspired us today

2012 - 971 (intake & ball funneling), 2056 (ball funneling)
2013 - 180 (shooting game objects inside of your robot)
2017 - 125 ( 4-bar intake)

Spectrum

Sunday, January 12, 2020

2020 Day 8: Quick Update

Power Cell Shooter Testing

Quick shooter testing video from today, we are now starting to believe we can make a more consistent shooter. Our plan is to have a wide 6" wheel and concentric flat hood. That will be were are next shooter starts.

https://photos.spectrum3847.org/2020-FRC/2020-Build-Season/i-ptLfBsS/A

Block CAD of the Robot

As subsystems start figuring out how much room they need we star laying things out in quick block sketches to make sure we won't have systems needing the same space and see how we can leverage nearby subsystem together.

This is all very rough and almost none of this other than the drive train will actually be on our robot. It's also missing an intake at the moment as we are still figuring out exactly what that will look like.
Spectrum

Saturday, January 11, 2020

Day 7: Making a few shots and a lot of misses.

Shooter Testing

We modified the shooter from our 2017 robot to be able to launch power cells. It's mounted to our protocube (just a cube made of 2x4s but we find lots of uses for it).

IMG_20200110_204734754.jpg

In 2017 it was one 775pro geared 4:1, it's now 2x 775pros geared 2:1. The hood has 1/8" rubber sheet to ensure the ball is rolling and doesn't slip on the polycarbonate panel. This shooter was based on the FRC#33 2017 shooter when be built it that season.

It shoots with 4 solid Fairlane nitrile rollers (RR-754-35W-RP). It also has been setup with two smaller diameter accelerator motors to attempt to have the effects of hand feeding the ball some what mitigated.

We are running it currently without velocity control, we have a small tachometer and it shows that the wheels are spinning at 5700 RPM at full voltage. This shows that the 775pros motors are having trouble getting the wheels anywhere near their free speed.

Video of some of the initial test can be seen on our photo gallery

This shot was about 25ft.
The compression at the tightest was around 2.5" (4.5" from wheel to hood).

Part of goal is to see how we can make consistent shots with a variety of balls. We will continue to play with this shooter setup tomorrow to see how we can improve consistency.

Our next prototype will be moving up to a 6" wheel to get it closer to the correct RPM range for the free speed of NEOs at 1:1 or slightly over driven.

3D Printing Prototype Parts

All this week we have been printing parts for prototypes.

Today we started making some larger parts. Wheel extension on the left, intake ramps on the left.
IMG_20200111_003743584.jpg

We have use countless Protopipe parts as well we printed up a bunch of HYPEblocks for the next iteration of our shooter prototype.

Robots that inspired us today

2017 - 33 (shooter)
2019 - 148 (elevator chain attachment)
WCP - Greyt Elevator V2

Sketch of the Day

Figuring out some of our climber geometry
IMG_20200111_004240665.jpg

Spectrum

Thursday, January 9, 2020

2020 Day 6: Advancing the complete idea

Robot Design Plan Updates

A little more thought, some more white board drawings and conversations, and a few bench tests have led us to a few design changes for our prototypes.

1. Shooter - reduce some complexity with fewer rollers and feed wheels than planed. Shooter and tower moved towards the front of the robot, to allow a much easier ball path while keep the intake behind it.

2. Shooter Hood - Two positions, a long wide shot that will make a ball into the 2 pt goal from behind mid court and up to the initiation line and a shallower angle that is specialized for 3 pt goal from a smaller range on the field. We are currently choosing to not shoot from the target zone.

3. Shooter Tower - Stop balls from entering the shooter by decompressing the top of the tower by moving one of the belts away from the ball. 

4. Climber - doesn't need to be directly over our CG it's okay if we curl a little while we solo climb as long as our climber is rigid. Climber has also moved to a standard single stage 2x1 elevator as it now longer needs to stay below our shooter path as the shooter is turned around on our robot.

5. Buddy Climb - The buddy climb forks are now powered down instead of being sprung down. We believe this will let us make it easier to keep the forks on the floor even if our CG isn't directly under the hooks.

IMG_2116_heic.JPG

Drive Train Update

CAD has been underway on our drive train since Sunday. There is still work to do but it's coming along nice. We have had issues with a large sheet metal front rail on multiple instances so this year we are planning to combine sheet metal drive rails with an extrusion cross bar that are put into compression with threaded rod and some 3D printed inserts on the side of the tube ends..


Robots that inspired us today

2013 - 610 (drive construction)
2019 - 148 (elevator & climbing legs), 971 (climbing legs and bumper mounting)

Sketch of the Day


Spectrum

Wednesday, January 8, 2020

2020 Day 5: "Sweet Spot" Parabola

Trajectory Calculators and the "Sweet Spot" Parabola 

For those of you that weren't involved in FRC back in 2014, you may not be aware that Aren Hill, a friend of Spectrum, "invented parabolas." During VEX's Build Blitz that season Aren detailed a method of deciding on your shot trajectory by defining a wide "sweet spot". The same principle should work this year.

During tonight's meeting we did some analysis using two tools published on chiefdelphi to calculate the trajectory of the ball from a shooter. Thanks to CMarley, and Sam Geckler for posting these calculators.

The goal is to find a trajectory to limit the amount of variations you need in your shooting mechanism, while maximizing the distance range from goal for which you can still put the ball in the goal.

Basic idea, have the top of your arc at the top of the goal and a long flat tail on each side of the apex that still allows your ball to go into the goal.

Here are a few of the graphs we made tonight.

A wide range of distance that make it in the outer goal.

A similar shot in the other calculator
 
A shot that focuses more on the inner 3pt goal

If you can tune your shooter to fire every ball at a similar trajectory you may not need to adjust your velocity or angle as much as you think.

Robots That Inspired Us Today

2013 - 1114 (Dingus), 118 (Frisbee Angle Deflector)
2016 - 2056 (Simple adjustable rigid hood)
2017 - 33 (shooter/feeder), 1986 (Single Big Shooter Wheel)
2018 - 2877 (vision)
2019 - 148 (Climber Legs)

2020 Day 4 - Design Review 1

Design Review #1

On Tuesday's during the season we have our design reviews. We use a common google slide document to collect design ideas, and then also to present subsystem progress to the entire team.

Today's review was mostly going over all the notes people have taken on past robots and ideas for things to include in our robot. Here are a few slides from our notes.


Shooter Intake Locations

One of the biggest things we have been discussion is the pros and cons of the relationship between different Shooter & Intake locations and/or the need for a turret. We finished our design review by listing the pros and cons or each individual option and the pros and cons of each combination. There was a lot of debate and thought to how our robot would actually play the game, 

Our current plan is to have the intake on one side of the robot and the shooter facing the opposite direction (Opposite - Separated) so we can easily acquire more balls in autonomous or from the feeder station and return to a shooting position without turning around. The feeder station may also be able to roll balls directly towards our intake.

Initial Subsystems List

We have a rough subsystem list of ideas we are currently pursuing. (robot will 45" tall)
1. Drive Train - 4x 6" Pneumatic - 2x Omni - 4 Falcon - Shifting (10.4fps - 19fps)
2. Climber - Extending drawer slides
3. Intake - Simple rollers over the bumper, limited to ~ 3 balls wide, funnels to 2 balls.
4. Ball Path - Smaller area funnels 2 balls into a single file belt tower up to the shooter
5. Shooter - Accelerator Wheel(s) and Shooter wheel with adjustable hood.
6. Buddy Forks- After we are hooked on, forks deploy under our robot that allow a <28" tall partner robot to drive under us and then we lift both of us higher into the air for both climbs.
7. Control Panel Spinner - Single NEO 550 in a VP or Ultraplanetary, driving two vertical rollers with a REV color sensor over the top of the wheel.

Robots That Inspired us Today

2010 - 469 (ball cycle)
2012 - 341 (Angled Bumpers, 3-2-1 Intake Path - Opposite Facing Intake/Shooter for Auton, Low CG), 987 (Narrow intake was able to be very effective)
2013 - 469 (full court or cycle)

Spectrum

Monday, January 6, 2020

2020 - Day 3 - Starting some tests

Today's Tests

Bump crossing tests - CG is important and braking hard is bad
VID_20200106_132605803
https://photos.spectrum3847.org/2020-FRC/2020-Build-Season/i-VQ2CwLV/A

Low CG and CG at the front of you robot handles the bumps better. Also this chassis has pneumatic tires.
VID_20200106_132909253
https://photos.spectrum3847.org/2020-FRC/2020-Build-Season/i-v9ftd6p/A

Intake Test
Protopipe has proved very useful for quickly making intake tests.
VID_20200106_184716242
https://photos.spectrum3847.org/2020-FRC/2020-Build-Season/i-CBtkmGp/A

Drawer Slide Elevator Test
VID_20200106_185134
https://photos.spectrum3847.org/2020-FRC/2020-Build-Season/i-SVGDst4/A

More videos and photos of these tests can be found on our photo gallery Photo.Spectrum3847.org - 2020 Build Season Gallery

Robots that inspired us today 

2009 - 67 (Multi ball shooter)
2012 - 48, 341 (Photo Gallery), 548 & 330 (shooter on a pivot)
2013 - 33(Frisbee path), 987 (gas springs on climber), 1986 (climber)
2014 - 2590 (ratchet)
2017 - 319 (ratchet)
2019 - 148 (elevator bearing blocks)

Sketch of the Day

Goals have the intake behind the shooter and enough room to hold 5 balls. Intake would be able to bring two balls up on to our robot at a time, those two balls would then funnel into a single file line.
Spectrum

2020 - Day 2

Climbing is incredibly valuable


If you are thinking about which tasks on the field to do, climbing is the most beneficial after only being able to drive successfully around the field and over the small barriers.

  • At 25 points (20+ over just parking), it is worth ~7 balls in the inner goal or 20 balls in the low goal. 
  • It can happen very quickly at the end of the match, leaving you time to do other teams like score balls, feed balls, & play defense.
  • It is points that only your robot can get. Your partners can pick up and score balls that you don't, they might be able to use the control panel to score points, but the 20+ points for you being off the ground requires you to be there.
  • If you and one other person on, your alliance can climb and balance your alliance receives a ranking point. 
The climb does not have to be difficult. This is the first time in some time where the only requirement for climb points is that your robot must be off the ground. (2013 was the last). If you are willing to be a tall robot, you can fold out an arm with a short (<8") pneumatic cylinder and use that to lift you 4"+ off the floor. There are also ways that you can climb be getting a hook on to the bar and using a winch to pull yourself. There are countless other options, but doing one of them successfully will make you much more likely to be picked for eliminations.

Control Panel Tasks are less valuable

In contrast to climbing, the control panel tasks are less valuable, and your team should strongly consider limiting the number of resources you devote to this task.
  • While there are a lot of points (35) associated with these tasks. Your alliance is required to score a lot of balls before these tasks ever become an option for you to get points. (29+ and 49+ balls) These ball counts will be rare in qualifications matches (and probably playoff matches as well) at many events around the world. You can be the best control panel robot in the world, but if you can't score enough balls to charge the 2nd and 3rd phase, you'll never be able to use your skill.
  • Even if your alliance is able to score enough balls, only one member of each alliance is needed to complete the tasks. Strongly consider where that robot should be your team, or if this is a task, you can leave to another member of your alliance.



Building Field Elements

We have started building our field elements. Working to make sure we can interact with our team elements in similar ways that we will be able to interact with the real field.

Image may contain: 1 person



Robots that inspired us today 

2006 Robots - 111 (Rack & Pinion Hood)
2012 Robots - 33 (linkage Hood, CD7 Intake, and J shooter path), 118 (intake only has grip in the middle)

2013 Robots - 1986 (Climber), 254 (climber)
2016 Robots - 195(scissor lift), 2056(climber)
2017 Robots - 971(rack hood), 33(accelerator rollers), 5803 (ball path)
2018 Robots - 33 (double reverse 4-bar), 125 & 1323(buddy climbs), 2056 (forks)
2019 Robots - 3940 (floating roller on intake)

If you're looking for some inspiration, here is a good place to see photos of some Aim High 2006 robots.
Pictures - 
http://www.firstrobotpics.com/?page_id=49

Sketch of the Day

A long robot (32-34") can store 5 balls in a line before entering a shooter.

- Spectrum

Sunday, January 5, 2020

2020 Day 1: Rules and Inspiration

2020 Infinite Recharge
Below is the game animation for the 2020 FRC Game Infinite Recharge. 

Rules

Most of our first day of build season was reading the rules for Infinite Recharge. We need everyone that is going to be helping design the robot to understand the game rules and the robot rules so they can help in that challenge.
The full manual can be found here - https://www.firstinspires.org/resource-library/frc/competition-manual-qa-system

Humans Play Infinite Recharge

We often have our team play the game out as if they were robots. It's mostly just for fun and it reinforces some of the field locations and names of the field objects. We apologize for the audio, filmed quickly on a phone. 



Robots that inspired us today 

2006 Robots - 217
2012 Robots - 971, 341, 254, 33, 118
2016 Robots - 3476, 1241, 33 (hood)
2018 Robots - 118(forks), 148 (wrangler)

We were looking at various ball paths and intakes from 2012 & 2016 robots that we may be able to use ideas from this season. We were also looking at various ways to possibly lift a partner off the ground with our climb as well.

Basic MCC Discussion

Our initial MCC (Minimum Competitive Concept) thoughts,
- low goal, human feed and simple floor intake through a bumper gap (over bumper is harder)
- hook flip out style climb that deploys and then you can winch up. Multiple robots in 2018 did this.
- no color wheel manipulation, it takes too many balls scored before this becomes valuable.

- Spectrum

Friday, January 3, 2020

2020 Spectrum Resource Collection

FRC CAD Collection - Blog - Link - Submission Form - CD

We created a simple system for collecting public CAD models of FRC robots and mechanisms. 
The FRC CAD Collection currently has over 450 links to robots from almost 200 teams.
Looking through the CAD of completed robots is one of the best ways to get better at designing FRC robots. You can be inspired by past mechanisms and build methods of teams around the world many you may never be able to see in person.

CADcollection.Spectrum3847.org

Protopipe Additions - Protopipe.Spectrum3847.org - CAD Files

We have added multiple new parts and a new mechanism example to the Protopipe system. We have included printable clamps, motor mounts, new connectors, drill adapters, and some small versions of previous connectors. We have also included an adapter block that allows you to combine HYPEblocks, a prototyping system made by FRC#5254 HYPE with protopipe elements.






Updated Guide to the FRC MCC


We updated our guide to the FRC MCC with new resources and tips. We added example MCCs from the 2019 season. We have added a section on sensors and counterbalancing mechanisms. We also updated most of the links and added new vendors to the recommended purchases.



Updated Spectrum Design Sheet

We have added Falcon 500s and both NEOs and NEO 550s to the mechanical section. We have reorganized several of the pages based on how we used it during the 2019 season. We have improved the BOM section and added a parts organization sheet. 

This sheet is how we organize our robot construction and helps us design mechanisms without having to re-lookup information over and over throughout the process.



FRC Maintenance Guide

This is the first year teams can do extensive maintenance and cleaning of their robots between events. Ideally, your robot should be squeaky clean and running at peak performance at the start of each event. We started working on a Maintenance guide to use internally but decided to make it public so that other teams could benefit as well. 

X-Ray 2019 Robot and Code

Below are our CAD and Code for our 2019 Robot X-Ray



Notes/Research

These are two very rough documents. These are just research docs for two different things we were interested in during the off-season.

  • Large aluminum pneumatic storage tanks
    • For robots that use a large amount of air, these ~2 gallon air tanks can be more weight-efficient than the plastic tanks teams often use. 
  • 6" Pneumatic Tires
    • We wanted to find a 6" pneumatic tire that could be used in a dead axle drive setup. There a lot of great options, some of our notes are in this document. 

Other Spectrum Resources

- Spectrum