FRC 95 The Grasshoppers 2019 Build Thread

Our hatch mechanism actually had a similar problem before we added more supports, beefed up the piston, and allowed it to pivot.

Some possible mechanism upgrades for our next event. Some inspiration from 78’s reveal video.


I like how 78 managed to stop the disc from flopping in the mechanism, without beefing it up too much. I’m heavily interested in further disc manipulator developments.

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Hi James, how do you land your #2awg DC wiring in the PDP? I’m finding the inputs are very tightly sized to the #6awg lugs provided in the KOP.

We grind down the sides of the 2awg connectors to fit on the PDP, as do a number of other teams.

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We did that for our week 1, it physically makes sense to me, and I’m willing to sign off on it as the team engineer. It doesn’t send a great message to my future-electrician students, who definitely should not be modifying equipment like that professionally.
(That objection is a little bit hypocritical, because I swaged the six gauge power poles to more easily fit 4 gauge wires already.)

The other option I’m thinking about is using a splice to go from 4 to 6 before it hits the PDP lug. But I really don’t want to introduce more crimps on the main harness, I think that is asking for quality issues.

We treat it as a good lesson in ‘if you know the rules (technical best-practices) and their intent, you can sometimes bend them.’ A great example is the battery itself. Many FRC teams are likely to exceed some of the rated operating parameters for the battery, but we do it anyway!


We got some upgrades installed over the weekend.

The 6in of float we added to the hatch collector have been awesome, and the spring re-centering has worked well.

We are pleased with everything except the bearing brackets for the collector and will spin those one more time before our event this weekend.


Can’t wait to see your bot in person at North Shore!

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@Dez you called it, we won an informal ‘easy inspection’ award at GSDE, due in part to our use of this wire track!

A few last-minute upgrades installed. We have an IR sensor array prepped to go onto the robot first thing this weekend to help with target alignment. Drive practice is looking good.

See you all in Reading!

Mother nature didn’t want us to forget that it was still winter last night while we were loading out.

Also, AndyMark got back to us about the battery issues that we observed at GSDE (I only emailed them yesterday, <4 hour response time.) They are replacing all of our batteries and sending the old batteries and date codes along to Interstate for them to check on. Great customer service!

In the meantime we have some new Duracell batteries from Batteries and Bulbs, who gave us a wonderful discount, that have tested well in drive practice. Those will let us rock and roll this weekend!


Good luck!

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Wow Andymark really does have the best customer service.


I just checked TBA and I legitimately laughed out loud when I saw you guys were 3-3-3 like how does that even happen how does a team tie three times


Man, it has been a really weird weekend so far. We want to go 1-1-1 tomorrow to finish quals at 4-4-4. For obvious reasons.


It was awesome watching you guys today. Undoubtedly the best robot at the event. I look forward to our match against each other tomorrow.


We started off the weekend finding a mis-assembly of our drivetrain after replacing our tires. This ran fine for over an hour of drive practice… god bless #35 chain.

We broke our cargo spring during an early match. We brought several replacements, but only needed one.

We learned the hard way that the cargo ship, especially its corners, can get pretty far into your chassis, especially if defense is being played on you. We got hung up on the cargo ship in one match, incurring damage to our main breaker. Luckily we didn’t lose power and eventually got free.

the defending team, 5962, were good sports about it all. This gave us a big laugh:

We wound up installing this breaker on 5735 after a quarterfinals match because their breaker was completely destroyed by the cargo ship. We also added a metal bracket over the breaker to protect it, which held up throughout eliminations.

In another match the corner of the cargo ship got 3-4in inside of our frame perimeter and damaged some of our wire track. It managed to disconnect our camera and displace our Athena.

To help prevent subduction on the cargo ship we added a raised ‘bumper’ and some brackets around the rear of our robot.

We lost an encoder wire in one match because it didn’t get re-secured after some work on the robot. This caused our ground collector to biff out in a match, then smoke a BAG motor when we were trying to debug it.

After a few rougher matches with some strong defense our solenoid manifold dislodged. Nothing damaged, we just needed to bolt it back up.

Our one main improvement for the event was a set of line tracking sensors that help us line up for collecting and scoring a little more easily.

2084 was having a tough time getting a hatch collector going, so we gave them one of our older MK2 hatch grabbers. They integrated it nicely!

After a really weird Saturday we were ranked 19th with a record of 3-3-3. We managed to complete 2x rocket RPs, which were really fun. One rocket we almost soloed, having one alliance partner score one low hatch for us. We completed the other 11 elements with some hatch panels being dropped off for us to ground-collect.

The ground collector was wonderful for shortening scoring cycles and the 2 or 3 times we missed a hatch placement.

We managed to get our act together for Saturday, winning our remaining 3x qualification matches, ending up in 7th. We were very fortunate to have the #1 seed 4761, the Robockets, pick us, and to scoop up 5735, the Control Freaks.

5735 had some technical issues crop up in the quarter finals, but as an alliance we got everything straightened out for the semis and finals. During finals 4761 had a bumper break apart, which was quite the rush to get put back together. Very exciting to have the whole alliance pitch in to get things cobbed back together for F2!

We managed to eke out the win in F2. We missed the final park in F2 after hearing a loud crack from our robot. Turns out one of our 3rd stage transmission gears gave up the ghost.

Luck, it seems, finally was on our side. Had we gone to F3 it’s likely we would not have been useful at all! We suspect that some misalignment of this gear stage from GSDE initiated the damage that ultimately lead to this break.

A big thanks to 4671 and 5735. You guys were awesome to play with, your drive teams are professional and good-natured, and we were really glad to take home some hardware with you!

During eliminates we managed to run 9-11 cycles per match, on par with our best qualification matches. It was very satisfying to see everything running well. However, we still think we can get faster. I think we’re at a B+ or A- level for this robot. Some tweaks to our cargo intake and hatch ground collector, and fine-tuning our automated alignment, will get us into A to A+ territory for this design.

3958, Schrodinger’s Cat, were one of our pit neighbors for the event, and they’re always a wonderful team to be around. After playing against each other in the finals, they left us a really special present: their piece of polycarbonate they bang on before the start of a match! They’re a real class-act team.


Congratulations on the win!

We really enjoyed the cookies!


246 is scrapping the hatch floor pickup that never was in favor of a set of these. I have a feeling we’re going to like them.

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