Chief Delphi - VEXpro Build Blitz 2015

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)

- General Forum (http://www.chiefdelphi.com/forums/forumdisplay.php?f=16)

- - VEXpro Build Blitz 2015 (http://www.chiefdelphi.com/forums/showthread.php?t=131582)

Re: VEXpro Build Blitz 2015

Quote:

Originally Posted by Ilovepineapples (Post 1414814)

Now we'll see the same VEX designs repeated over and over by all teams using the same pre-fabricated parts. We'll have some nice looking robots and VEX will have a bigger pocketbook.

Gunna continue beating the dead horse:

The same criticism can be applied to AndyMark. The build events have always been commercials to me. But I don't see this as wrong. Businesses are going to be businesses and do things that businesses do. Expecting a business to not be a business is silly.

Re: VEXpro Build Blitz 2015

Quote:

Originally Posted by Ilovepineapples (Post 1414814)

I do not see this as a positive development. I won't go outright and say I dislike it but I feel this will narrow the designs we see even more than in Ri3D.

Now we'll see the same VEX designs repeated over and over by all teams using the same pre-fabricated parts. We'll have some nice looking robots and VEX will have a bigger pocketbook.

This is still America, right?

And I like it that more new and under-resourced FIRST teams can roll and score! It is as if VexPro were mentoring hundreds of teams (ordinarily left to flail) which is a good thing. The more students that leave smiling, the better!

As a mentor I liked the concept of ri3d but at the same time seems to squash the creative side. I try very hard to get the kids on our team to think outside the box.

I should have included that much can be learned from the quick build teams though. The choochoo design has been around for a couple hundred years, but until you see it incorporated in new tech people seem to not notice. All the quick build teams do a great job and I will never take that away from them.

Last year I had to flat out tell a couple mentors that wanted to basically copy one of the bots NO.

I mentor for one reason.,. To see the members have that ahh ha moment, when what ever we are working on clicks in their head and they get it, and have learned something new.

Re: VEXpro Build Blitz 2015

Here's the list of resources that we're working on for Build Blitz 2015.

http://www.buildblitz.com/recycle-rush-is-here/

Quote:

Originally Posted by BuildBlitz.com

Drivetrain Design Guide & Philosophy: This game is VERY different from previous years. There are many new design considerations for teams to take into account, even for something which used to be very “cookbook” – like drivetrains. Our team will provide some detailed information on how to design the perfect drive for YOUR team’s needs.
AM14U2 Upgrade: We’ll be providing detailed information on how to upgrade your AM14U2 drivetrain using VEXpro drivetrain components. We know many teams want to take the base level functionality provided by the kit and improve it to suit their team’s needs. The Build Blitz team will be showing you detailed options for these adaptations.
VEXpro 2015 Specific Drivetrain: After discussing the possibility of creating a 2015 Drive in a Day, our team decided it would be more beneficial for teams to use the lessons learned from the Drivetrain Design Guide & Philosophy and apply them to a few examples. We’re going to provide you with some drivetrain designs which are specifically tailored for the 2015 game.
Simple Game Piece Manipulation: This year’s game has large opportunities for “simple manipulation” of the game pieces on the ground to SIGNIFICANTLY contribute to alliance success. We’re going to provide some detailed education guides and examples for how to handle all three of the 2015 objects. Methods like Plowing, Pulling, Tipping, or even Sliding may be investigated. There are tons of subtle things that teams should take into account, and we’ll help to get a jumpstart on your learning.
Simple Stacker: Lots of teams are looking at ways to place one tote on top of another. We think we have some cool ideas on how to lift totes, stack totes, place totes on scoring platforms, and put totes onto the step for “coop-ertating”.
Linear Elevator: Teams want to lift heavy things high in the air. We know why. We can help! We’re going to provide some guides on designing a simple linear elevator, one of the most efficient and simple ways of doing so. We may even design some new VEXpro products specifically to help with this aspect of the game!
Claw Designs: Teams are interested in grasping and manipulating the Totes and Recycling Containers. We’ll be providing some educational resources and examples for doing so.

I'll be releasing a strategic analysis of the game this evening, followed by a live an interactive webcast that explains the analysis. Both Paul Copioli and I will be giving our thoughts on the game and taking questions from the community. You can watch the broadcast here:

https://plus.google.com/events/cn261...kk6q9hs5o00t7s

Re: VEXpro Build Blitz 2015

Here's the Strategic Analysis that I came up with in conjunction with the Build Blitz team.

http://www.buildblitz.com/build-blit...egic-analysis/

Paul Copioli and I will be talking about it in depth tonight at 9:00 PM eastern. We'll also be opening the floor for your questions. Make sure you tune in!

https://plus.google.com/events/cn261...kk6q9hs5o00t7s

Re: VEXpro Build Blitz 2015

Karthik and Paul are LIVE for their Strategic Analysis here:

https://www.youtube.com/watch?v=coC1j7T0840

Join the conversation, especially the Q&A at the end!

Re: VEXpro Build Blitz 2015

Thanks for a great session, and for answering so many questions! Tying a rope around the starting recycle bins is truly an outside-the-box thinking idea that I had yet to hear.

Re: VEXpro Build Blitz 2015

Quote:

Originally Posted by JesseK (Post 1422380)

Thanks for a great session, and for answering so many questions! Tying a rope around the starting recycle bins is truly an outside-the-box thinking idea that I had yet to hear.

You're very welcome! Hopefully it spurs more outside the box ideas. There's a lot of unexplored territory with the major changes introduced this season.

Re: VEXpro Build Blitz 2015

Thanks to the Build Blitz team! Just watched the Elevator Video/Blog on the Build Blitz Blog page. Can someone tell me how the elevator will hold the totes elevated? ( what will keep the gearbox from back driving) Thanks in Advance

Re: VEXpro Build Blitz 2015

Quote:

Originally Posted by Mr. B (Post 1423841)

Thanks to the Build Blitz team! Can someone tell me how the elevator will hold the totes elevated? ( what will keep the gearbox from back driving) Thanks in Advance

Potential Solution

This is how The GreenHorns decided to solve this problem.

Re: VEXpro Build Blitz 2015

Quote:

Originally Posted by Mr. B (Post 1423841)

We're working on prototyping and testing several different applications of these linear elevator parts. Having a mechanism that can backdrive is not necessarily undesirable, but what most people mean when they discuss backdriving in terms of arms or elevators in FRC is when the mechanism falls due to gravity after the operator controls are released.

To help prevent this form of "backdriving", there are several ways to accomplish this, including using the built in PID functions in the FRC code library to hold the elevator at it's current position. This, combined with gearing the elevator such that the stall current at the motor is minimal (e.g. won't smoke a motor) and adding constant force springs to help counterbalance the weight, will help make a fast and responsive linear motion system.

The current iteration of our elevator prototype is geared to quickly pickup totes (<1 second to bottom stack) with a single BAG Motor and 2-stage VersaPlanetary gearbox, while the motor remains at 25% of stall current with an elevator load (carriage + tote weight) of 60lbs. This is without any constant force springs to help counter-balance the system.

For implementing PID controls, I've had good success previously (most recently in 2011 when I was on 228) using Sharp IR distance sensors for elevator height control. For this, it was as simple as mounting the sensor on the robot chassis looking up at the elevator carriage to measure the height of the elevator.

Re: VEXpro Build Blitz 2015

Do you have any data or rules of thumb on how much current the CIM/MiniCIM/BAG motors can take for how long before they smoke?

Re: VEXpro Build Blitz 2015

Quote:

Originally Posted by BuildBlitz.com

Claw Designs: Teams are interested in grasping and manipulating the Totes and Recycling Containers. We’ll be providing some educational resources and examples for doing so.

Here's the final product put together by the claw group. It's a remarkably simple solution that can easily be made using only hand tools.

http://www.buildblitz.com/pinchclaw-...drawing-files/

Re: VEXpro Build Blitz 2015

Some more educational resources have been posted.

A full guide on how to design a claw for Recycle Rush.

http://www.buildblitz.com/claw-design-guide/

Quote:

Originally Posted by BuildBlitz.com

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.

A full guide on how to design a drivetrain for Recycle Rush.

http://www.buildblitz.com/drivetrains-for-recycle-rush/

Quote:

Originally Posted by BuildBlitz.com

There are a lot of factors which need to be considered when designing a drivetrain for the 2015 game. Refreshingly, a few of the “historical” constraints have been removed. In addition several aspects of the game may shift a team’s traditional design requirements. This is cool because it forces designers to discount their pre-conceived notions and it provides a fun thought exercise. We love fun thought exercises!

Lots of people ask “what do you recommend for this year’s game?” The answer is always: the simplest drive that does everything dictated by your strategy. (See Karthik’s Strategic Analysis). In our minds this probably means the following for most teams:

Moving sideways is very helpful when trying to align & stack Totes
Stick to a “traditional size” base — just because the rules allow for giant robots doesn’t mean it is a good decision
If you’re gearing faster than 10 ft/sec free-speed, you’re probably going too fast
You should try to find a configuration which crosses the scoring platforms; using 6” diameter wheels is a simple way of accomplishing this
Focus on reliability — you need to maximize every match, not just “escape with the win”.

Whatever you choose to do, focus on that last point. Consistency is critical in 2015. Good luck to all teams! Send any comments or questions to prosupport@vex.com for more help.