Build Week 4 2017 is in the History Books

What a week. awards, robots, planning for districts, designing t-shirts, testing final designs, finishing cad, assembling the drive train and more all happened this week.  On top of that we picked up nearly 8 new team members which brings us up to 54 students, making this the largest team we have ever had.

Let go by sub team

Awards – the awards team is putting the finishing touches on all of our awards.  we have awards due on Feb 9th and Feb 16th.  We also have a chairman’s video and a tech journal du by our first competition.

Planning for districts – we have a the pit map nearly worked out and are almost finished planning food. we are going to need a lot of help at our event being held at Walt Whitman High School on March 10-12.

Designing t-shirts – we are nearly done with our t-shirt design for the year.  Last chance for sponsors to get on the t-shirt is Feb 12.

Testing final designs – the team spent the first part of the week nailing down the geometry for the major robot components.  We are going into his season with a much better understanding of how different designs interact with the game pieces.

Finished CAD – now that our final testing is done we were able to complete our CAD. We should have something to release in the next few days.

Driver practice – drive practice continues for the 3rd strait week.  But tis was by far the coldest driver practice yet.  Since we set up outside things can get a little chillie.  Driver practice this week could have gone better though, we were plagues by breakages of all 3 working drive trains.

Drive train – the drive train is fully assembled and functioning.  We even used it for driver practice this week.  We were able to identify a few problems with the design and spent some time on Saturday getting the issues fixed.

Pneumatics – As part of this year’s drive train we have had to re learn pneumatic since we have not used them in the last few years.  We found a few leaks and learned how the pneumatics system as a whole worked.  Our system is now leak free and functioning correctly with 4 actuators.  This week we add 4 more.

Electrical – we now have our electrical board designed and mocked up.  We are putting the finishing touches on the CAD and will be getting that cut this week.  This will be the first time we have had a CNC electrical board and accounted for all of the wire runs and tubing runs.

Fabrication – We are up an running on one CNC machine this week and will soon have a second CNC running to do larger pieces. By this time next year the team will be able to make nearly all of our own parts as custom as we can design them.  This is a big step forward for us and should result in lighter more efficient robots going forward.  Also, our bumpers are nearly done.

The Robot – We are only a few days behind our schedule, but tis year’s schedule is aggressive.  We want to be completely done with the primary and secondary goals by the end of week 5 so we can work on our tertiary goals during week 6 while the code and drive team work out all of the kinks.

Scouting – our lead scout has joined the drive team this year, but that has not stopped him from putting together the stats on who we will be seeing at our week 2 event.

Coding – the team has been working on the driver station UI, octocanum code, manipulator code, vision code and Ohm (our initial build).  We have instituted code reviews and organized code merges.  This is has been helping ensure our code team that is 8 members strong aren’t wasting each others time.

Safety – we had some serious safety issue this week so we had a complete stand down and made everyone go back through tool safety training.  This was the closest we have ever been to a serious injury and definitely help put safety into perspective.  We may have lost a few hours of build season, but the time spent making sure we have a safety culture is worth it.

 

 

The first CHS District Championships was truly epic

First off, congrats to all of the amazing competitors and winners from this weekend.  We had so much fun and learned a lot from you.  We can’t wait to do it again next year.

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Award Winner
Regional Chairman’s Award 384
Regional Chairman’s Award 1885
Regional Chairman’s Award 1086
Regional Engineering Inspiration Award 540
Regional Engineering Inspiration Award 1629
District Championship Rookie All Star Award 5830
Woodie Flowers Finalist Award Jesse Knight (1885)
Volunteer of the Year Jill Wetzel
FIRST Dean’s List Finalist Award Marcus Osborn (2537)
FIRST Dean’s List Finalist Award Andrew Miller (540)
FIRST Dean’s List Finalist Award Chenelle Foster (5830)
FIRST Dean’s List Finalist Award Collin Stiers (1719)
District Championship Winner 5804
District Championship Winner 1418
District Championship Winner 836
District Championship Finalist 1137
District Championship Finalist 346
District Championship Finalist 1262
District Championship Finalist 422
Creativity Award sponsored by Xerox 346
Entrepreneurship Award sponsored by Kleiner Perkins Caufield and Byers 422
Excellence in Engineering Award sponsored by Delphi 623
Gracious Professionalism Award sponsored by Johnson & Johnson 888
Highest Rookie Seed 5804
Imagery Award in honor of Jack Kamen 2377
Industrial Design Award sponsored by General Motors 339
Industrial Safety Award sponsored by Underwriters Laboratories 4945
Innovation in Control Award sponsored by Rockwell Automation 1418
Judges’ Award 4945
Quality Award sponsored by Motorola Solutions Foundation 5279
Rookie Inspiration Award sponsored by National Instruments 6194
Team Spirit Award sponsored by FCA Foundation 1111

 

Secondly, thanks to all of the volunteers, sponsors, organizations, parents, mentors, students and everyone else who helped put on this weekend’s event.  You did an amazing job and we can’t thank you enough.

Robot_thanks2_large

 

Thirdly, this weekend was pretty hard on us, we were chasing a systems issue the entire time, and it really only let us run in about 5 of our 12 matches.  But, in the end we were able to find the issue and make some modifications to the drive train and arm that should make us competitive at world championships. Special Thanks to 2363, 1418, 686 and 836 for helping us work through our electrical issue, and to 3389 for picking us for their eliminations alliance.  Those two eliminations matches may not have ended the way we would have hoped, but they allowed our team to get some of our mojo back after finding our systems issue.

highfive

 

Lastly, thanks to the electrical bug for making us fail and learn.  Right from the first match you challenged our spirit, our resolve and our confidence.  We spent nearly 16 hours over 3 days looking for you.  We changed countless components and code trying to isolate you. We asked for help from the FTA’s, mentors and students and in the the end it was the recommendation from 686, our alliance partner to change the main breaker that eventually lead us to you.  We learned to power through, not give up, ask for help and in the end we are a better team because of you.

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In two weeks we travel to St Louis, we are stronger, we are smarter and we are ready to take on any challenge that comes our way.

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Here are all of the pictures from this weekend.

We are officially qualified for district championships

We are ranked 25th out of 132 in the CHS district. This weekend we competed at the Central Maryland District event and finished raked 15th and nearly moved into the finals against the number 1 seeded alliance. That’s the good news.  the bad news is that we need to earn nearly 8 points to earn a slot to championships.  Going to need to do some serious heavy lifting this event to make up that differential. Congrats to all of the winners.

Award Winner
District Chairman’s Award 1629
District Engineering Inspiration Award 836
Rookie All Star Award 5945
District Event Winner 836
District Event Winner 1629
District Event Winner 3941
District Event Finalist 1137
District Event Finalist 4067
District Event Finalist 686
Creativity Award sponsored by Xerox 686
Entrepreneurship Award sponsored by Kleiner Perkins Caufield and Byers 2199
Excellence in Engineering Award sponsored by Delphi 1389
Gracious Professionalism Award sponsored by Johnson & Johnson 612
Highest Rookie Seed 5945
Imagery Award in honor of Jack Kamen 2377
Industrial Design Award sponsored by General Motors 1137
Industrial Safety Award sponsored by Underwriters Laboratories 5830
Innovation in Control Award sponsored by Rockwell Automation 888
Judges’ Award 1123
Quality Award sponsored by Motorola Solutions Foundation 623
Rookie Inspiration Award sponsored by National Instruments 5936
Team Spirit Award sponsored by FCA Foundation 5979

 

Also a big shout out to FIRST Chesapeake, FIRST action, Americore Vistas, volunteers, FRC team 1111 the Powerhawks and all of the sponsors for making this weekend possible.  Your efforts, energy and treasure are changing the world and we can’t wait to see you again in 2 weeks.

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This weekend was a great learning experience on a few fronts.

  • We learned about how our robot performs from a mechanical consistency perspective as it relates to shooting.  We made some small tweeks and were able to get our shooter fairly mechanically consistent.
  • We learned that manual targeting is not really viable for winning matches.  If we really want to use high goal shooting in any real way we will need target assist or auto targeting.
  • We learned how to get 20 point auton working.  We just have a few more tweeks to make and it should be ready for prime time at district champs.
  • We learned about more auton modes.  We made 6 new auton modes this weekend and should have a few more auton modes ready to go once once we get the Navx IMU integrated.
  • We learned about our need for speed.  Currently our robot is speed limited to help with driving.  We are going to start increasing the speed to help us get to where were need to be faster.
  • We learned we are ok at defense.  We played defense a few rounds in our attempt to beat the robobees, and are planning to avoid that in the future.
  • We learned that our drive train needed a little TLC.  So we did a complete inspection of the drive train and made some repairs at the end of the weekend.
  • We learned how to integrate 2 cameras onto the robot.  So we now have 2 cameras mounted and usable by the drivers.
  • We learned about the importance of centering the ball in the intake before taking a high goal shot.  So we added an IR sensor to the intake to help with ball centering and created ball centering functionality.

 

Here are all of the videos we have from the weekend.

 

Here is our plan for the next two weeks.

  • Vision code – started

    • Auto targeting – not started
    • Targeting assist – not started
  • Auton code
    • 20 pt auton – started
    • 15 pt auton – started
    • integrate NavX – started
    • defense reset – started
  • Main code part 3 – started
  • Competition documents part 3 – not started
    • Tech Journal part 3 – not started
    • Judges Packet part 3 – not started
    • 1 sheeter part 3 – not started
    • Pit Video part 3 – not started
    • Bill of Materials part 3- not started
  • Pre-competition scouting part 3 – started
  • Pre season scouting and risk survey part 3 – started
  • Climber pushed to world champs
  • organize pit not started
  • Identify parts we need to order not started

 

Loaded in

We loaded in to our Edgewater event today and were the 4th to complete inspection and the first to hit the practice field.  Once we were there we never left, we just kept working on our high goal shooting and had mixed success with our newest arm. Oh did we forget to mention we made a new arm, yeah we made a new arm and it is a bit better in some ways and has introduced mechanical variability in a way we had not expected.  So now we are trying to find the right combination of mods to make it more reliable. Once we have that done high goals should be pretty easy for us.

 

 

We also learned about a cool new way to tranfer power using flexable shafts from S.S. white.  Check this out.

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Review and planning meeting today at 4:30 pm

Today the team will go over what went well, what did not go so well, what we need to change and what we want to do more of so that at the next competition in Edgwater in a week and a half we see improvements. we will also ask everyone if they want to do something different at the event, would they like to try a different role.

We are also going to announce a policy change for the team, for every event going forward all students will get a minimum of two days off prior to and after each event to make time available to study.  This means our stop work day for the Edgwater event in March 23rd.

Since we did not meet yesterday the list of things to do has not changed much, but we have added a few hings

  • Vision code – started
  • Main code part 2 – started
  • Strategy part 2 – not started
  • Scouting system part 2 – not started
  • Awards part 2 – not started
    • Chairman’s video part 2 – not started
  • Competition documents part 2 – not started
    • Tech Journal part 2 – not started
    • Judges Packet part 2 – not started
    • 1 sheeter part 2 – not started
    • Pit Video part 2 – not started
    • Chairman’s presentation part 2 – not started
    • Bill of Materials part 2- not started
  • Pre-competition scouting part 2 – started
  • Pre season scouting and risk survey part 2 – started
  • Climber pushed to after second event
  • Defensive Cheescake – not started
  • Refurbish robot cart not started (lost new cart at competition, need to start again)
  • Paint Pit – pushed to after first event
  • Upgraded alpha turret and arm – not started
  • Fix bumpers – started
  • Add camera mounts and two cameras – started
  • identify parts we need to order – not started

 

 

Presenting our 2016 Robot: Maelstrom

Maelstrom is the result of a thousands of hours of work put in by Walt Whitman students, volunteers, parents and sponsors to play this year’s FRC game Strong Hold.

Specifications:

Drivetrain Speed: 12 ft./sec

6 wheel west coast drive with 8” wheels

14.5” inches tall

Single fly wheel shooter capable of 13 ft. max shots

Over defense shooter arm can be raised to any angle up to 90 degrees

Shooter arm fully turreted

All motion encoder enabled

Navx field location capability

3 Auton Modes:

Damage low bar

Damage rough terrain

Damage ramparts

Robot Has Demonstrated:

Score 2 high goal cycles in 2 min

Score 4 low goal cycles in 2 min

Defeat Low Bar

Defeat Ramparts

Defeat Rough Terrain

Defeat Rock Wall

Carry Boulder over all Defenses

Robot Plans to Demonstrate:

Defeat Mote

Defeat Portcullis

Defeat Chavel De Freis

Defeat Sally port with Partner

Defeat Draw Bridge with Partner

Score 4 high goal cycles in 2 min

Score 6 low goal cycles in 2 min

Score boulder in Auton

 

Everything you want to know and more about this year’s robot can be found in our tech journal

 

 

5 Days Left

The Beta arm is on the robot.  When it comes to getting things done The Walt Whitman Robotics Team knows how to make crunch time count.  The last week has seen students put in enormous effort to work past our 2 mechanical challenges and get the this robot across the finish line.

For the next 4 days the robot belongs to the coders.  They need to get all of the encoders working, the functions working, the robot driving strait and the shooting sequences down.  Not to mention they need to get the shooting constants and PID loop constants figured.  They will be putting this bot through its paces so that when we get our 6 hours of open bag time all we do is drive, drive and drive.

Next up for most of the team is getting all of our competition prep items done. We have a lot to do to get ready for this competition and will need everyone to pitch in so we can get everything we need done over the next 3 weeks done. March 11 will be here before we know it.

The team is also considering losing about 10lbs by making a new turret and shooter arm so we can add a climber.  Currently the bot is at 110lbs and we have not tested any climbers.  This is a secondary priority for us so this may take some time since we do not want to sink to many people into this with so much else to do.  However a crack team of students will start to play around with some prototypes so that we could make a Beta arm by the district championships that could just strap on and add some more functionality.

This weekend we have had a change of plans.  The whole team will be in the lab Saturday from 1-8.  On Sunday our drive teams and code teams will go to the FTC tournament being held at Georgetown Prep and get a full day of practice / demo in.  Thanks FIRST Chesapeake for making this happen.

Here is what the team has left to do;

  • Drive train – done
  • Bumpers – started
    • Red – done
    • Blue – started
  • Electrical board – done
  • Turret arm prototype – done
  • Turret arm – done
  • Turntable – done
  • Shooter – done
  • Vision – started
  • Main code – started
  • Strategy – done
  • Scouting system – started
  • Awards – started
    • Chairman’s – done
    • Wood Flowers – done
    • Entrepreneurship – done
    • Dean’s – done
    • Chairman’s video – started
    • Media award – started
  • Competition documents started
    • Tech Journal started
    • Judges Packet started
    • 1 sheeter started
    • Safety Binder started
    • Pit Video started
    • Chairman’s presentation started
    • Bill of Materials – not started
  • Pre-competition scouting – started
  • Inviting local leaders to events – done
  • Bellypan – done
  • Pre season scouting and risk survey – started
  • Reveal video started
  • Climber – not started
  • Defensive Cheescake – not started
  • Wiring installation – started
  • Driver Selection done
  • Team Standard – started
  • T-shirt – started
  • Battery cart refurbish – not started
  • Refurbish battery leads started
  • Refurbish robot cart – not started
  • Paint Pit – not started
  • Alpha turret and arm – not started

 

 

The strategy is locked in

Big day yesterday. We locked in our strategy and have moved on to detail design.  Our CAD team is hard at work taking all of the decisions made yesterday and turning them into a robot.  Gear ratios are being calculated, sensors are being picked and free body diagrams are being drawn.  In a nut shell, this week will be all about the Math.  To make the equations match reality we will be doing a full robot prototype this week to start to test nearly every aspect of our design so that we leave as little as possible up to chance.

The team has locked in out awards approach. This is a little more flexible as we will be having our first awards meetings this week to start writing.

The team has all but 4 field elements completed.  We should have them all done by the end of the week.  We are also going to make a second Sally Port to send over to the STEM Action center so that all of teams in the area have a complete set of fields to practice on.

We are in a bit of a bind from a parts perspective at the moment.  Now that we know what we are doing, many of our suppliers are out of what we need.  A very specific pain point is the lack of pneumatic wheels, until we get a full set we can’t pick out drive team. So next week we will be feverishly trying to get parts ordered before they run out again… Fingers crossed.

 

 

Video from our workshop this weekend.

 

PS. you will learn more about a strategy in week 6…

PSS. One Hint. One of our tertiary goals is named the guillotine, Muh huh hu ha ha ha ha !!!!!

Welding Fasteners and Adhesives

A joint is a junction where structural elements meet without applying a static load from one element to another. When one or more of these vertical or horizontal elements that meet are required by the design to have be fixed

Permanent fixed joint – joints that can not easily come apart. Permanent fixed joints should be used when the detail parts or assemblies being joined have low or no repairability requirements.

  • Welding
    • Useful method of joining materials
    • Strong joint if welded properly
    • Joint is susceptible to fatigue failure, so make sure the material is think enough to withstand the number of cycles you are expecting
      • A cycle could be something like there will be 40 joint flexures per match, the team expect 100 matches so make sure the joint could withstand 40 x 100 x 2.5 = 1,000 or 10^3 joint flexures for the season
      • Weld fatigue life calculator
    • Only weld in properly set up designated areas with a trained professional while wearing the correct safety gear
  • Adhesive
  • Rivets
  • Mortis & Tenon
    • Use only if fabricating robot parts with wood

 

Temporary fixed joint – joints that can easily come apart. Temporary fixed joints should be used when the detail parts or assemblies being joined have high or mandatory repairability requirements.

  • Bolts & Nuts

    • FRC team should standardizing parts to reduce the number of tools needed, to reduce confusion, speed up repair times and reduce weight. Here are the bolts we recommend;
      • 8-32
        • Use socket head for FRC application
        • Come with protruding and flush head configuration
      • 10-32
        • Use socket head for FRC application
        • Come with protruding and flush head configuration
      • 1/4-20
        • Heavy weight steel fastener that is very strong
        • Use only when absolutely necessary
        • Use socket head for FRC application
        • Come with protruding and flush head configuration
    • Bolt size selection guide
    • Nuts
  • Screws
  • Pins

 

Additional Resources

 

Structural Systems

Two major systems of every robot on the planet are the structures and mechanical systems. Structural systems allow the machines and buildings to hold themselves together and up off of the ground. Listed below are some of the more common structural systems that teams use in FRC.

Structures

In FRC there are two major off the shelf structural systems; versa frame and aluminum slotted framing. Many teams will use one or both of these structural systems because they require a minimum amount of fabrication knowledge and access to tools. Here are some details about each of these basic structural systems;

  • Versa frame
    • Versa frame comes pre-drilled 5/32 holes
    • Versa frame comes in a variety of shapes and lengths
    • Versa frame has a wide variety of brackets to allow for joining pieces
    • Versa frame has scribe lines to help with drilling additional holes on center
    • Versa frame can easily be pared with West Coast Drive mechanical system components
    • Versa frame can easily be paired with Vex Pro mechanical system components
    • Versa frame is moderately expensive
    • Versa frame is heavy
      • Team’s can drill lightening holes in 1″ x 2″ frame components
  • Aluminum slotted framing (referred to as 80/20)
    • Slotted frame comes formed with a variety of profiles
      • Profiles are the cross section of the extrusion
    • Slotted frame profiles work with a variety of fasteners
    • Slotted frame has a wide variety of brackets to allow for joining pieces
    • Slotted frame has scribe lines to help with drilling additional holes on center
    • Slotted frame can easily be pared with 80/20 mechanical system components
    • Slotted frame is heavy

 

All of the other structural systems should be considered custom solutions. Custom solutions may require more in house fabrication skill and knowledge than most teams have. They may also require some specialized tooling. Here are some of the more popular custom solutions in FRC;

  • Fastened or welded tube
    • Square tube (tube with no pre drilled holes)
      square

      • Weight based on material
        • Carbon tubes – light
        • Fiber glass tubes – light
        • Aluminum tubes – moderately heavy
      • Easy to work with
      • Lots of standardized brackets available
      • Need to be able to precisely drill holes
      • Can be welded or joined mechanically
    • Rectangular tube (tube with no pre drilled holes)
      rectanle

      • Weight based on material
        • Carbon tubes – light
        • Fiber glass tubes – light
        • Aluminum tubes – moderately heavy
      • Easy to work with
      • Lots of standardized brackets available
      • Need to be able to precisely drill holes
      • Lightening patterns can be custom machined
      • Can be welded or joined mechanically
    • Circular tube
      round tube

      • Weight based on material
        • Carbon tubes – light
        • Fiber glass tubes – light
        • PVC tube – heavy
        • Copper tube – heavy
        • Aluminum tubes – moderately heavy
      • Need special tools for bending
      • Need special tools for crimping
      • Moderately hard to source brackets
      • Can be welded or joined mechanically
      • Need radius blocks for fastening
      • Need to be able to precisely drill holes
        • Some suppliers do have tube with pre drilled holes available
  • Bent sheet metal
    sheetmetal

    • Usually joined with rivets and bolts
    • Light weight
    • Need to create CAD
    • Need to be able to create flat patterns
    • Need to be able to manage CAM package
    • Need to be able to precisely drill holes
    • Need to be able to cut sheet metal precisely
    • Need to be able to bend sheet metal precisely
    • Need to be able to accommodate spring back
  • Machined sheet or block
    • If metal usually joined with rivets and bolts
      machined

      • Light weight
      • Need to create CAD
      • Need to be able to manage CAM package
      • Need to be able to precisely drill holes
      • Need to be able to cut metal precisely
      • Need access to vertical mill or CNC router
    • If wood usually joined with mortise joint and glue
      wood

      • Light weight
      • Easy to work with
      • Need to create CAD
      • Need to be able to manage CAM package
      • Need to be able to precisely drill holes
      • Need to be able to cut wood precisely
      • Need access to vertical mill, CNC router or laser
      • Need to be able to clamp and glue wood precisely
  • 3D printing
    3dprint

    • Light weight
    • Need to create CAD
    • Need to be able to manage CAM package
    • Need to be able to model supports

 

Fixed Joints

To avoid high material costs and the need for large scale 5-axis CNC mills most teams will need to design their structure so that it can be easily manufactured with the tools or sponsors they have. This usually results in a structural system that will require many fixed joints. Fixed joins are joints that resist motion along and around all three axis. Check out our page on free body diagrams to learn more about how motion along and around all three axis can be understood. And then check out the page on welding, fasteners and adhesives to lean more about how to create a light weight fixed joint.

 

Structural System Design

Structural Systems need to be able to withstand the expected structural loads over an expected number of cycles. Teams will need to follow these steps necessary to design their structural system.

  1. Sketch out a idea
  2. Build prototypes
  3. Refine the sketch
  4. Refine the prototype
  5. Create a free body diagram
  6. Understand the loads
    1. Understand ultimate load case for each type of loading
    2. Understand the number of cycles for each load case
    3. Do the math
  7. Select materials that can resist the loads
  8. Define the shape that will resist fatigue and is manufacturable

Note – steps 3 and 4 may need to be repeated many times to find the right combination to reduce weight and fabrication complexity

 

Additional Resources