Build Blitz 2015 – What a Rush!

Recycle Rush is here, and the 2015 Build Blitz team has tackled this complex engineering challenge head-on.  Our hope is that the educational resources, guides, and insights created during the past week will help all teams in their pursuit of superior performance.  Check out the highlights below!

Karthiks Strategic Analysis VersaFrame-Linear-Elevator-thumb Pinch Claw Design Process Interviews Simple Tote Puller (front) AM14U2 with VEXpro Upgrade 4-Bar Stacker Mecanum Thumbnail

Educational Resource: Karthik’s Strategic Analysis (and Live Google Hangout)

The first major event of the week was Karthik’s Strategic Analysis, an exclusive application of Karthik’s proven “strategy dictates design” methodology to this year’s game.  After taking a day to digest the rules and scrutinize its intricacies, Karthik was able to create a prioritized list of design goals intended to maximize a team’s scoring potential.

The Analysis continued that evening with a live Google Hangout alongside the President of VEX Robotics, Paul Copioli.  Karthik spent some time detailing his strategic priority list before he and Paul took questions from the FRC community.  The ensuing conversation was engaging, exciting, and (at times) surprising – if you watch one thing from this year’s Build Blitz, you won’t want to miss this!

Design Concept: VersaFrame Linear Elevator

VersaFrame Linear Elevator
CAD file (STEP, 5.76 MB)

Stacking Totes is one of the primary (and most versatile) scoring opportunities in Recycle Rush.  Whether you’re going for the 40 point Coopertition Stack or building stacks on Scoring Platforms, this is a year to go vertical.  A standard chain-driven linear elevator is an efficient way to accomplish this feat, and one Build Blitz team undertook the challenge of creating one entirely out of VersaFrame.  Two new VEXpro kits later, they succeeded.

Download a STEP file of the VersaFrame Linear Elevator here and visit the VersaFrame Gussets page to order the new parts required to build your own!

Design Concept: VersaFrame Pinch Claw

Recycle Rush features an element that hasn’t been seen in FRC for several years: multiple types of gamepieces to manipulate. One Build Blitz team took it upon themselves to overcome this engineering challenge by developing a simple pinch claw that can manipulate both Totes and Containers. The results were promising – check out the CAD file or drawings below to build your own out of VersaFrame.

Educational Resource: The Design Process and Recycle Rush

All successful FRC teams, without exception, implement and follow some sort of design process.  The Build Blitz participants are well-versed in their own versions of the engineering design process, having used it for years both on their own FRC teams and in their “real world” jobs or projects.  We sat down with each team to ask them a few questions about how they view the design process and how they are applying it to Recycle Rush.  The result was one of the most insightful and valuable posts of the week – check it out to find out how they’ve had to adjust their processes this year, how teams can get by without access to CAD, how to avoid common FRC design mistakes, and more!

Reliability and consistency are paramount. If you do ONE thing, every single match, without fail, you will beat the guy who does many different things poorly. Every time.

Design Concept: Simple Object Manipulators

Simple Tote Puller (front)This year, one Build Blitz team tried something new.  While custom elevators and linkages are great ways to help elevate the mid-tier of teams, we wanted to go even simpler.  How could literally a few pieces of hardware be attached to a basic robot frame and still create a solid contributor to a qualification or playoff alliance?

Forks Mounted on Drive BaseThe passive hook and plastic slider prototypes kicked this direction off with great success.  It turns out that a few pieces of VEX EDR metal and a sheet of polycarbonate are all that is needed to successfully move Totes around.  The second release was a set of forks made out of VEX EDR metal that could manipulate both Totes and Containers, achieving Karthik’s most important strategic goal.  These ideas are all about keeping it simple and effective, a crucial lesson for any team looking for a place to get started.

Educational Resource: Build Blitz 2015 Drivetrain Design Guide

PDF, 2.1 MB

Recycle Rush introduced a new element into the mix that has never been seen before in the FIRST Robotics Competition: a nearly complete lack of size requirements.  Thanks to this exciting new dynamic, creating a 2015 “Drive in a Day” that would suit all teams was no longer a feasible option.  Instead, the Build Blitz team put together a comprehensive Drivetrain Design Guide.  This year, there isn’t a “one-size-fits-all” drivetrain – the ideal drivetrain is the one that fits YOUR robot’s needs.

While the guide was created with the 2015 game in mind, it touches on many “evergreen” fundamentals of drivetrain design that will also apply to future years.   Explanations  for angle of approach, “Crayola CAD”, and an introduction to proper speed and gearing calculations are all included (just to name a few).

When you’re firing up your drivetrain for the first time, and you’re testing to see how it transitions over the bump, remember one thing: center of gravity & weight play BIG roles in the way it will perform.  Test your robot in “real life” configuration.  Fully loaded, including any game objects it might be carrying.

This field has one other obstacle designers need to consider: PARTNER ROBOTS.  This is especially important if you’re not crossing the scoring platforms.  Make sure you think about traffic flow before you build an “aircraft carrier” robot and expect to drive it around with impunity — you have two partners who may also have aircraft carriers!

Educational Resource: Claw Design Guideclaw-cover

Recycle Rush features another element that hasn’t been seen in FRC for several years: multiple types of gamepieces to manipulate.  More than ever, proper claw (manipulator) selection and prototyping is crucial to teams’ success.

This guide will help teams learn about a few common manipulator styles and choose the claw that works best for them.

“Due to the nature of competitive robotics, nearly every game involves some sort of object manipulation. Whether it’s picking up an object and placing it on a goal or gripping onto a field element, claws are an extremely common method of object manipulation that most teams consider at some point during their design process. Claw designs can be as varied as overall robot designs, but most fall under one of three categories: roller claws, pivot/pinch claws, and passive/fixed claws. The purpose of this design guide is to introduce these three primary styles and to help teams evaluate the best manipulator for their needs.”

Design Concept: AM14U2 VEXpro Upgrades

The Recycle Rush Scoring Platform features one of the sharpest approach angles in recent FRC history.  If traversing this short but challenging bump is part of your team’s strategy, then proper drivetrain analysis, design, and testing are essential to ensure a smooth transition.

With a few minor modifications, the 2015 Kit of Parts drivetrain can be easily adjusted to use VEXpro 6″ Traction Wheels and belts. This upgrade allows your drivetrain’s wheels to maintain full contact with the ground through its entire journey, reducing the risk of frame damage or becoming stuck.

Design Concept: 4-Bar Stacker

This 4-bar stacker was designed to stack up to two Totes on the Step – ultimately using this to assist in gaining Coopertition points. The concept of a 4-bar is common in FRC designs due to its simplicity and effectiveness, qualities which are readily apparent in this design. Powered by a VersaPlanetary Gearbox and Mini CIM motor, this linkage can be paired with a pinch claw or other manipulator to stack Totes with ease.

Design Concept: Mecanum Drivetrains

One of this year’s desired drivetrain design traits, as identified by the Drivetrain Design Guide, was side-to-side (holonomic) motion. Thanks to a complete lack of defense and the necessity of precision alignment for maximum scoring, being able to strafe sideways is a no-brainer for Recycle Rush.

While many teams are often hesitant to bet on a mecanum drive due to its weak performance under defense, these unique wheels actually fit the bill nicely for this year’s challenge. The Build Blitz team put together two options for creating a Mecanum VersaChassis, using both the classic Single Speed Double Reduction Gearbox and the new for 2015 Single Reduction Clamping Gearbox.