FIRST Robotics Competition Blog

Week 0.5

Mar 02, 2016 Written by Frank Merrick.


Here are a few quick notes from our experience over the weekend at the Palmetto Regional in Myrtle Beach, South Carolina, USA.

First, areas for improvement:

Cheval de Frise 

The Cheval de Frise defenses didn’t hold up well during the event, often breaking when hit by robots. This breakage was not revealed during our testing here at FIRST HQ or during the Week Zero scrimmage, and we know why. Turns out, we assembled the defenses we tested using hand tools, but when we got into production mode, we started using power drills to secure the bolts. These drills put more torque on the bolts, stressing on the planks in the defense, make them susceptible to breakage. We’ve redesigned the planks to use a counterbore, rather than a countersink, in the bolt areas. This greatly reduces the stress on the polycarbonate when tightening the bolts, and our new testing here has shown this fix works well. All events will be getting the newly designed Cheval de Frise planks, starting with this week’s events.

At Palmetto, we had to take the Cheval de Frise out as a defense option for several hours as we worked to find a temporary solution at the event. We apologize to any teams that wanted to use this defense during this period and weren’t able to.

Movable Defenses

We wanted the defenses in FIRST STRONGHOLD to be moveable, but between matches, not during matches. What’s harder than getting over the ‘Rock Wall’? Getting over the ‘Rock Wall’ if it runs away from you when you make the attempt*. In a few matches during the Palmetto event, the straight pins we were using to secure the defenses in place weren’t getting the job done. We switched to curved pins for Saturday, which improved things tremendously. We’re still testing which curved pins will work best, but you can expect this situation to improve for Week 1 events.

Low Bar Fabric Rips

We had to replace several pieces of Low Bar fabric. We’re testing more robust fabric now, along with improved means of repair. We don’t expect to have the new fabric available for this week’s events, but we do expect to be able to improve repairs of the existing fabric. Also, Inspectors will be looking at the leading edges of any actuators on robots that will contact the fabric. If you have a sharp edge, Inspectors may ask you to cover it with tape or take other steps to make it less likely to snag and rip the fabric.

Next, some ways teams can help themselves. These were mentioned in the Team Update published last night, but they are worth listing here too:

Field Walk-Ons

If you walk onto the field after a match, but before the tower lights turn green, it’s a yellow card for you. This is a safety issue and should be easy to avoid. Please remind your fellow team members. Everyone’s excited to get their robot back to the pits, but please take a breath and double check.

Rockin’ the Castle

You should expect the opposing robots to drive at your castle wall at high speed during auto, slamming into it. If your operator console isn’t secured, it may go flying. There is a strip of hook and loop tape on the shelf in the player station that holds your operator console. You should consider putting a mating piece of hook and loop tape on the bottom of your operator console to help it stay put. See Section of the Game Manual.

Tighten Those Connections

It’s not just the castle that’s rockin’. FIRST STRONGHOLD is an energetic game, and your robot is going to be bouncing around. Loose wires = sad teams. You don’t want to be making one last defense crossing, getting ready for a tower capture, only to have your robot die on the field just short of a big win.

Finally, some serious air

I couldn’t resist including this. Check out this shot of FRC Team 2815, Blue Devil Mechanics, from Columbia, South Carolina, USA, at the Palmetto Regional. They’re still at the venue right now, waiting for this one to land!

Photo Credit: Blue Devil Mechanics


*Hmmm. Defenses that defend themselves. Note to self for 2017.

Back to Blog


There were a couple flying robots. Besides 2815, Muffins did a lot of flying over the defenses.

How are those blue bumpers legal with all of that red showing?

Are the ref flags different this year?  They look like they have logos on them.

Add new comment