FTC 2015 Scrimmage (CANCELLED)

2015-11-14 @ 3:00pm - 7:00pm

This event has been cancelled.

(Note that this page was for the non-DISD scrimmage on the afternoon of November 14th.  The DISD-only scrimmage on the morning of November 14th is still taking place as scheduled.)

 

EV3 software and sensor blocks (gyro)

At the EV3 programming clinic, people were asking how to get the Gyro sensor block. The Education edition should already have the gyro sensor block, the retail version does not.

To get the retail version of the EV3 software, visit http://www.lego.com/en-us/mindstorms/downloads/download-software .  Then at Robot Square – Adding Sensors it describes, step by step, how to add the Sensor blocks. One quick hint, here is a direct link to the Sensor Blocks download at Lego.com. The sensor blocks are about halfway down the page.

Good luck and have fun programming

FIRST in Texas grants – Oct 15 deadline

From the October 2015 issue of the FIRST in Texas Newsletter:

Just Two Weeks to Apply

The final deadline is almost here! Submit your completed applications by October 15 at 5pm CST.

What is a completed application? Make sure you:

  • Submit our Team Grant Application
  • Upload Photo Release forms for each team member
  • Upload an Eligibility Form for Texas high school teams

Mark your calendars and ask your questions now! For other details on the grant process, like a timeline on notifications and awards, visit our Grant Calendar.

FTC hardware, tools, and tips

[last updated: 2015-11-03]

This page contains recommendations on tools and hardware components to consider when building a FTC robot.  To simplify ordering, items are organized by vendor/source, with explanations and other tips in the notes at the bottom.

Suggestions for improving this page are greatly welcomed.

AndyMark

McMaster-Carr

ServoCity.com / Actobotics

Powerwerx.com

TETRIX Robotics

Modern Robotics

Amazon.com

Monoprice.com

Commonly available hardware and materials

(Home Depot, Lowes, Amazon.com, etc.)

BDCS40G

Popular Vendors

Notes

1. Many teams highly recommend the AndyMark NeveRest motors over the TETRIX motors.  They cost about the same ($25), but the NeveRest motors have an integrated encoder ($5 cable versus the $80 TETRIX encoder kit and $3 motor power cable) and do not burn out as quickly if stalled (2.9 minutes versus 7 seconds).  Motor stall burnouts can be a common problem with the TETRIX motors, especially for new teams.

2. For each motor you plan to add to a robot, don’t forget all of the other components you’re likely to need that go along with it.  In general, just plan that every motor added to the robot will require a motor ($25), motor mount ($16), motor hub (2 for $6), encoder cable ($5), and a port on a motor controller (2 ports for $80).  Also, it’s a good idea to plan spare capacity if you can: some parts go out of stock during a season, and rush shipping can get expensive when the team decides it really needs another motorized attachment on the robot in the week before a competition.

2a. The TETRIX W39376 motor mount is the same price as the W39089 mount that comes in the standard TETRIX kits, but is much more versatile and easier to use.

3. In some seasons it’s feasible to do without the official game elements, for the 2015-2016 Res-Q game it would seem that ordering at least a half-field set is required to adequately test and plan a robot.

4. The surface on which the robot travels can be a significant factor in navigation, especially during autonomous mode.  We recommend obtaining the official gray SoftTiles flooring that is used in competition.  Some teams elect to use foam tiles available from local hardware stores, but these are often subtly different (usually thinner) than the SoftTile flooring, can cause the robot to drive differently, and aren’t substantially less expensive than the official SoftTiles.  Also, gray SoftTiles can be ordered directly from the manufacturer for less than the AndyMark set; a full field requires 36 tiles, but some teams order a few spare tiles in case some tiles get damaged with use.

5. The official field perimeter walls are really expensive ($659 + shipping), so teams looking to save some money can potentially do without these.  The FTC Team Resources page has instruction for building lower-cost versions of the border walls.

6. The “KEP nuts” that come with the TETRIX kits are okay for getting started and for quickly attaching components together when prototyping, but they often come loose in competition. Nylon insert lock nuts (“nyloc”) are a good investment, and cost approximately $5 per box of 100.  A typical robot build should have 200 to 300 nuts available for building.

7. Hex power bits and hex insert bits fit powered screwdrivers and other bit screwdrivers, which can greatly speed assembly/disassembly of components.

img_20150930_125253-003 7a. Use colored tape, paint pens, or nail polish in the center of hex keys to make it easy to quickly identify their size.  Many teams adopt the color convention used in the FTC Robotics book:  red = 7/64″ (socket cap screws), green = 3/32″ (hub set screws), blue = 5/64″ (button cap screws and newer collars).  The mnemonic phrase is “Red socks, green hubs, blue buttons”.

8. The battery power connectors that come with the Tetrix batteries eventually wear out with usage (connecting/disconnecting), causing power resets or outages during matches.  FTC recommends replacing these connectors with Anderson Powerpole connectors.  Powerpoles are available in 15-amp, 30-amp, and 45-amp ratings; the connectors are the physically same (and interchangeable), the difference is in the size of the contact barrel that holds the wire.  TETRIX batteries and module power cables typically have 14 gauge wire that require the 30-amp contacts, battery chargers and motor cables usually have smaller wires that use the 15-amp contacts.

9. The TRIcrimp tool works really well for crimping Anderson Powerpole contacts, but it’s also possible to get other crimp tools to work.  If you don’t want to invest in the TRIcrimp tool to do your own connections, there are several teams in the region that will be glad to help you with Powerpole connections.  Just ask on the NorthTexasFTC forum.

10. You just know that one battery pack isn’t going to last a full day at competition.  Some teams swap batteries after every match, others after every 2 or 3 matches, going more than that can be risky.  And if your team is on an alliance in elimination matches, you definitely want fresh batteries for that.

11.  It’s a good idea to have a fully-charged backup phone available too (with the team’s robot controller app installed), in case a phone is damaged or runs out of battery just before or during a competition.  The spare phone could be used as either a robot controller or driver station phone.  In a pinch, it’s also likely you could borrow a driver station phone from another team, since all driver station setups are essentially the same (the main difference is which robot controller phone they are paired with).

[wpanchor id=’otg’} 12. The OTG cables that Modern Robotics supplies (to go between the robot controller phone and the Core Power Distribution Module) have proven to be very unreliable.  After just a few insertions and removals the pins no longer made a solid connection, leading to dropouts and disconnections during game play.  FTC recommends replacing these cables with higher quality USB cables, such as the ones listed above from Amazon.com and Monoprice.com.

New sensors from Modern Robotics

In the past week Modern Robotics has announced two new sensors to its lineup, a color sensor and an integrating gyro.

The color sensor claims to support a passive mode, which allows it to detect color from an external light source (such as the LEDs of the Res-Q game beacons).  It also supports an active mode, where the sensor has its own light emitter to detect the color of a reflected target (similar to how the LEGO Mindstorms and HiTechnic color sensors work).  The color sensor is available now, but as of Sep 21, 2015 the FTC Robot Controller App doesn’t have libraries to support the sensor.

 

The gyro sensor is a 3-axis gyro that does onboard integration of the z-axis, thus it can be used to calculate heading with greater accuracy than if the calculation is performed on an Android or PC host.  The gyro is slated to be available for sale by mid October 2015.