I use vexcode - where can I call PID?
You donāt exactly call it. Since PID is mostly used for keeping things from moving or moving to a target setting, what you do is you tell the motor where to set to and the PID keeps it there. For example, if you put brake type hold onto a motor and try to turn it by hand, you will most likely break the motor as the PID will keep it from moving from its position.
I see. I was talking about something different, I think, cause P control ramps down motor power
I think itās because they edit all the failed parts out of the videos.
I think one reveal has bloopers and it showed the robot failing. Not all designs will be perfect
P-control is only one, more simple, part of PID. PID control involves three unique variables that allow a subsystem of the robot to reach a target or maintain a target position extremely accurately. The integrated PID is best for maintaining a position but it is not designed for moving systems as one would think. This is because you canāt tune it and physics will work against you.
What this means for a tray is that you would need your own PID control loop to deposit stacks smoothly. You do not want the motor to go at 100% velocity while depositing. Though you can use the integrated PID and just decrease the velocity of the motor, the motion of the deposit will not be as smooth as a custom-tuned PID loop. You want to go near max velocity at the beginning of the deposit and slow down significantly the closer you get to the target angle (~90 degrees).
It isnāt difficult to understand how this can be an extremely powerful tool if you read up on PID loops, but for anyone confused as to why the integrated PID wonāt work effectively: itās because you canāt tune it to your specific case. The motion of the deposit will be jerky and simply not as good as a custom-tuned loop.
With almost every single traybot that Iāve seen their stacks have been tipped over. I think only I very refined traybot would do better than a DR4B.
Could you elaborate on what type of design would outperform a tray bot? At least in Hawaii, top teams (well, just the team to beat) have gotten good at placing stacks without tipping. In finals at East Oahu 4142B was able to place a 7, 8, and 9 stack just during the driver controlled period of the match.
yes Dr4B cannot stack as many cubes they can stack onto of existing stacks. They are also more reliable with stacking in towers. If there was an elimation round and I have a DR4B, I would chose a traybot for my alliance partner. And likewise if I had a traybot I would choose a DR4B. Therefore the alliance is well balanced.
Does the tilting mechanism that uses the 1 motor move up with the tray or does it stay on the chassis?
Moves up with the tray. Itās more precise that way.
Hi everyone.
was wondering if anyone is aware of the dimensions (height width length) of the actual robots
Robots have to start in a 18āx18āx18ā space, but can expand once a match starts.
This thread is not for covering this question and it is an old post, please do not revive this thread.
Looks really cool. I suggest trying to find a way to make it color sorting for more efficient scoring but other than that looks really efficient and well designed. Good job 
where this team from.
42700? Itās in the details on robotevents
Hello Mr. Talbert, we are first year vex robotics members and are planning on building a robot similar to this. I was wondering if you had any tips about constructing the base, lift, and intakes. We love how your robot is able to score in an efficient manner, and would love to build something of a similar manner.
Thank you,
Team 8568B (MA)
No offense or anything, but if youāre a first year team with no experience, you probably shouldnt be attempting this.
Although if you think you can get one done in time, then you can try. Itās more difficult than it looks though
Thanks for the compliments, Iām proud that the robotics community is able to benefit from something I create 
I have a couple of tips / tricks that I learned over the revisions Usagi has gone through.
Base
Take care to make your base as stiff as possible. Square your holes using shoulder screws or nut retainer nubs. If youāre using 3.25" wheels you can use standoffs to screw 18t sprockets to the wheels to reduce slop on the drivetrain. I recommend offsetting the middle wheel using a nylon washer. It helps make sure the center wheel makes consistent contact with the tiles, regardless of whether you decide to run H or booster wheel.
Lift
Make sure to brace your lift towers. There are plenty of guides out there which detail the methods of bracing your towers. They take incredible loads due to the amount of weight mounted to the lift. I highly recommend thoroughly bracing your lift. Until you find what works and what doesnāt for your implementation, overbuild. High Strength axles are overrated in my opinion. Proper bracing makes up for the axes and is necessary even with high strength axles. I donāt recommend using 1x1 on any part of the lift, they take too much strain in this design. In addition, itās not uncommon to have stability issues, and tipping will wreck those 1x1 angles faster than you can say ā27 USDā
If you plan to stack on stack make sure that your lift has enough linearity to put the stack out in front of the drive. With the Usagi portrayed in the reveal video, I had issues reaching the highest tower because of how far back the intake assembly swung. I now have both arms the same length, and actually end up with the intakes moving slightly forward when lifting.
I recommend using two motors for a dr4b because it lets you run a respectable gear ratio. This grants you the ability to intake many cubes and score towers in succession.
Intakes
For me the intake structure stayed pretty much the same, the positioning and mounting is the most important component, though. Two c channels (One on top one on bottom) protected the rollers against incursions which might have popped the intake. I power an 18t sprocket with a screw joint mounted idler 12t. Iād recommend having the 18t mounted in the back but depending on your intake situation your solution may vary.
I recommend mounting the intake such that it is at a slightly flatter angle than the tray, and contacts cubes on the ground near the top of the cube.
Iāve looked into double roller intakes but the way my intakes are mounted there isnāt much space for them to stick out in front of the robot.
Bonus / General
- Booster wheel is more useful than H drive because it helps conserve the turning motors for turning.
- Three-stage tray is reasonable. Have the third section held by the intakes
- Have the intakes banded down so that you can have a faster deployment https://youtu.be/-AD0SqNTTJ0
just as @Railgunawesome said, itās tough to do Usagi, but I wouldnāt strongly recommend against it. Good luck!
Those who dare to fail miserably can achieve greatly.
- John F. Kennedy
Just noticed I didnāt properly answer your question. Weāre a team from Saint Louis School in Honolulu, Hawaii.
Ah u fine. Dont worry. It pretty cool video just wanted to c if we will have to deal with them soon us being in ga i would guess it only be id we both make worlds