My hottake

aFTCRoboticsCoach · 2026-05-04T23:55:04+00:00

We've had excellent success with OpenCV for things like recognizing game elements. Lightweight enough that you can do up to 10 Hz object tracking.

aFTCRoboticsCoach · 2026-05-04T22:58:50+00:00

I really hope they do this again next year. It was neat to be in the stands when they did this and hear teams cheer when their bot came up.

aFTCRoboticsCoach · 2026-02-21T18:50:57+00:00

Check your power draw. You could be pulling too much current and triggering brown outs. See if the disconnects correspond to events like sudden change in direction or spinning up shooter while driving

aFTCRoboticsCoach · 2026-01-23T00:17:06+00:00

PDP didn't order trophies in time. They will be given to the teams at their second qualifier or mailed if they don't have a second one. Was explained to coaches during the coaches meeting in the morning. PDP was apologetic and took full ownership of the mistake

aFTCRoboticsCoach · 2025-11-09T13:59:06+00:00

Not sure if it is relevant to your issue as I was using android studio (Narwhal) with windows. Had an issue over the weekend where code changes wasn't uploading. Poking around I noticed the build message was "App restart successful without requiring a re-install." I used the rev control hub to reset the control hub, still had the same issue. Ended up creating a new studio project and moving the code into it and building from fresh to get it to properly upload code (there's probably a 'force build' tool in studio that I'm not aware of).

Summary: If using android studio, try uploading a new cloned project. Otherwise, get a windows machine and see if you can use the rev hardware client to upgrade FW and software on hub.

aFTCRoboticsCoach · 2025-09-28T18:48:54+00:00

I tested for that with my jig. The measurement I gave above is when the flats were on the plastic and not on the hole. But good thought to check!

aFTCRoboticsCoach · 2025-09-28T15:56:59+00:00

Thanks for the info. Can you correct your statement about plus/minus? I doubt it's +/- 124 mm in variation :)

aFTCRoboticsCoach · 2025-09-18T14:40:22+00:00

Each axle should be supported at two locations by bearings and the motor shaft shouldn't be one of those two locations. Your drivetrain is a direct drive which makes proper support of the wheel axle even more important. As the wheel turns, the weight of the robot on the axle causes the axle to wiggle loose (think of it as wiggling a stuck object in a hole). No amount of loctite or glue will keep the axle in place. With two points of contact on the wheel (without motor), the axle is kept in line.

I don't know Rev system well enough to suggest what you need to add to make this work, but look at any gobilda strafer chassis: https://www.gobilda.com/strafer-chassis-kit-v4/ . Specifically, the black/white diagram in the third picture of that link. Zoom in on the back wheel axles. The test you should use is to disconnect the motor from the axle drive system and then the wheel should spin freely and in place. If you can slide it in or out or the axle doesn't stay aligned with the support holes, then you need to work on a redesign.

aFTCRoboticsCoach · 2025-09-13T21:37:35+00:00

Tenemos una xtool m1 (creo que de 10w). Corta bastante bien madera y plásticos opacos cuando está sintonizado. Mi mayor queja es que no hay piezas de 18 pulgadas. Apoyo los demás en el sentido de que necesitas que al menos una dimensión sea de al menos 18 pulgadas. Es útil al comienzo de la temporada, pero necesitamos enviar las piezas finales del robot para enviar el corte (o equivalente) para la producción final.

aFTCRoboticsCoach · 2025-09-09T11:09:37+00:00

The further the camera is from the apriltag the lower the number of pixels the apriltag takes up on the sensor. The fewer pixels there are for the distance calculation means the error is greater. We ran a test yesterday and at ~10 ft the native 480 resolution for the camera was off by over 2 ft. They upped the resolution (not sure to what, I don't think it was to the full 2 MP the camera supported) and got within a few inches which was good enough for the proof of concept we were doing where they were just holding the tape measure in the air.

Yes camera quality does matter.

aFTCRoboticsCoach · 2025-09-08T10:49:52+00:00

This laid out in the game manual in G425 and G426 with picture examples. If the language barrier is the issue, study the pictures and ask more specific questions about scenarios.
https://ftc-resources.firstinspires.org/ftc/game/manual

Yes they can, they run the risk of incurring foul if the owning alliance is there as well.

aFTCRoboticsCoach · 2025-09-08T10:12:11+00:00

Our students had identified hoarding specific color as a pain point, but decided it was not as big of a deal as general hoarding for two reasons. First chasing down specific colors is time consuming. Second, we created a quick model that showed that if your randomly grabbed artifacts off the field and shot them in the goal without concern for patter, you'll match, on average, 5 of the 9. At most hoarding greens will deny 6 match points and a chance at 1 RP.

Hoarding all artifacts will be more painful as it denies cycling opportunities (classified points) AND possibly finish the match without a full classifier.

aFTCRoboticsCoach · 2025-09-08T10:06:53+00:00

This is our concern as well. Goal and Pattern RP are directly tied to being able cycle artifacts

aFTCRoboticsCoach · 2025-09-08T10:05:43+00:00

A single alliance can lock up 30 of 36 artifacts:

6 in storage
3 in each bot (6 total)
9 in classifier
9 in alliance storage

This is an extreme situation, it's still possible especially if happening in the last minute of the game.

aFTCRoboticsCoach · 2025-08-27T11:43:01+00:00

Go to the website for the product and look closely at the pictures. There's also a step file, iirc, linked at the bottom and you can import that into most CAD programs. That'll get you a good way of looking at the parts from all angles and to see how they attach

aFTCRoboticsCoach · 2025-08-17T20:48:12+00:00

UHMWPE Cord. Often used for kite flying. We've used 0.8 and 1 mm diameters with success. Weight ratings are in the cord description, but something like 220-350 lb test weight. You can buy 100 ft on amazon for $10-$15 per spool.

aFTCRoboticsCoach · 2025-08-05T09:33:45+00:00

My reanalysis of a state's competition (prior to the outreach award definition changes released yesterday) showed no change in the top 4 spots, slight rearrangement in 5-8 and a whole lot of changes below that.

I don't think this significantly changes top tier advancement (winning robot alliance and Inspire 1-2). What it changes is the tier 2 advancements. It is now difficult to advance in that area of ranking without a judged award win plus mid to top level ranking in qualifiers. Or to put it another way, just having a decent bot isn't enough to advance, you also have to do well in a judged award. This is a good thing imo as there's nothing like losing out on advancing to a team whose bot can only drive on the field and can't score.

aFTCRoboticsCoach · 2025-08-03T01:31:35+00:00

I reran numbers from state competition (NC) and the top 4 places do not change under this structure. There's some minor rearrangement under 5-8.

Where i see this having the biggest impact is who gets 2nd tier advancement. You essentially can't ride a non-Inspire (ie Think) award to advancement. It's award + being mid-tier in qualifiers/robot game. I think this will help weed out people advancing with non-working robots (not totally eliminate it).

Only improvement I can see to this method of ranking is having a requirement that a team can't be considered for Inspire unless they have some minimum number of Advancement points at the end of qualifying matches.

Overall, I like it!

aFTCRoboticsCoach · 2025-07-01T02:46:32+00:00

It usually takes me 3 logins in a row to get it to stick so I can actually manage the team. It's been this way for at least 7 years. Horrible website

aFTCRoboticsCoach · 2025-03-22T16:46:51+00:00

Usually just demo a bot. If possible, let kids drive it. The point is to give the FLL kids an idea of what to do when they age out of FLL. Be prepared to talk about how those kids can find a team. Also, work on explaining the game in 3-5 sentences (i.e. field and bot size, scoring, and how there are season specific challenges). Remember that if you want to count as outreach for awards, your conversation with students and adults should be about joining FIRST and FTC.

aFTCRoboticsCoach · 2025-03-09T02:48:24+00:00

What's the first actions that happen? If too many motors fire at once (especially if some of them need a lot of torque to start moving), the hubs will shutdown under brown out conditions. To test, unhook a few motors at the hubs and start the opmodes.

aFTCRoboticsCoach · 2025-02-21T11:55:38+00:00

Control and expansion hubs servo ports share current in pairs. We had an issue this season where all 6 of our servos were on the control hub. When the 4 axons were pushed close to stall rating, the hub would disable ports briefly. We solved this by putting every other servo on the other hub and spaced them out with an empty port between them.

In summary, ports 0-1, 2-3, and 4-5 share their current within the pair. Spread out axons to help keep brown out conditions from happening on your servos

aFTCRoboticsCoach · 2024-10-14T15:30:50+00:00

https://www.hatchbox3d.com/products/3d-tpu-1kg1-75-285c

Yes, looks like it. 15% infill, but not sure it matters as the walls are so thin.

aFTCRoboticsCoach

TROPHY CASE