Ri3D 2020 Robot Walkthrough
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- Опубліковано 5 сер 2024
- The official 2020 'Snow Problem Robot in 3 Days Walkthrough Video - showcasing our robot, Hyperion!
Additional Resources
'Snow Problem 2020 Chief Delphi Thread: www.chiefdelphi.com/t/ri3d-sn...
'Snow Problem 2020 White Papers: drive.google.com/drive/u/2/fo...
Track: Ascence - Places Like That
Music provided by NoCopyrightSounds
Watch: • Ascence - Places Like ...
Free Download / Stream: ncs.io/PlacesLikeThat
None of this is possible without our generous sponsors:
AndyMark
University of Minnesota
The Thrifty Bot
Thank you for your support! - Розваги
What's very interesting and awesome is that our teams current design is so similar to yours! Sadly we don't have the resources to build it in 3 days, but I'm definitely going to take this back to my team to improve ours before it's built. Awesome job!
Cool
For the telescoping lift, how did y'all slowly retract it? Is it just gravity but unspooling it so that it goes against the spooling motor?
Nice! By how much does the polycord encroach into the 7 inches of the ball diameter (in theory based on pulley centers and diameter)? Any other insights in the use of polycord for ball transfer?
2:28
The pulleys on
either side are 8.25” apart, or 6.25” cord to cord. Polycord works well and can be easily configured for different path shapes. You should make a jig to clamp the polycord edges when you melt them together for the best connection.
Just a quick question, how many inches did you guys compress the ball in the shooter and how fast does your shooter spin (rpm)?
1 inch compression
The shooter spins at about 4600 RPM. We should have gone faster to get in the inner goal.
What is the structural framing with the two holes in the end that you use . Where do you purchase it. Thanks
Peanut Tube: www.andymark.com/products/peanut-extrusion-different-lengths-options
Another question: what did you guys use to coil the string? Did you guys use a specific type of winch?
The winches are all coiling around Andymark metal spacer stock. The end plates are waterjet cut.
How is the AndyMark redline motor working as far as consistency? Last year both of ours failed because of poor heat distribution. The end result was that the copper holding the brushes basically melted off and caused our robot to malfunction...
You have to be pretty careful with these, and not stall them under too much load. We only use Redlines/775pros for either low load or mostly free spinning applications where they don't see sustained current draw. motors.vex.com/ has some great information about how quickly these motors burn out under load (the Redline is very similar to the 775pro)
How do you avoid the rope binding up in the pvc?
The pvc inner diameters are 1/2 inches apart, so with thickness of the pipe there’s enough space for the paracord to slide. We also used modified pvc T-connectors on the bottom two stages to hold bearings for the rope to run over. It also helps to cut notches for the knots (knotches, as I like to call them) in the bottom of the pipes so that they can nest without jamming into the knots
I'm wondering how you guys mounted those acrylic panels on the sides of the bot. I don't see any mounting directly on the panels.
They're just mounted with adhesive-backed Velcro which lets us take them on and off without too much trouble.
Can you confirm the motor/gearbox you used for the lifting mechanism? It looks like 775 RedLine with 57 Sport Gearbox.
The cascading lift to place the hook was a Redline on a 16:1 Sport gearbox. The actual climbing was two CIM motors on a 24:1 gearbox and a 0.7" diameter spool
How long is the linear actuator that you used to move the control panel mechanism?
4"
Also how did u mount the climb? Did u make a footprint of the shape of the pvc?
We used a solid pvc flange bolted through a metal plate on the bottom of the robot. We also added a crossbar from the top of the telescope motor mount to the frame for extra support.
Oh ok got it thank you!!!
So with the safety bumpers, you’re robot meets the lengths requirements?
The bumpers aren't part of the overall frame dimensions. The frame itself is approx. 32x27, which fits inside the 120" perimeter
where did you get the 2" mecanum wheels?
they are from thriftybot but I believe they are sold out, if you want a 3D-printable solution I would recommend this chief Delphi thread www.chiefdelphi.com/t/frc125-2-printable-mecanum-aka-v-i-w-release-2019-2020/369139
so is it legal for someone to use your design? I see you list the cad files online, does your robot comply to all this years rules? I am no longer a mentor, a local company took over, I am curious though.
We try to make the robot legal for this year's game, because otherwise it's not very useful as a teaching material. Some things do slip through, notably size constraints (we stick out about 1/4" front and back) and a few other minor details.
Do you have public CAD?
www.chiefdelphi.com/t/ri3d-snow-problem-2020/369115/13
What is the length of the pneumatic cylinder for the Control Panel Manipulator? Thank you!
It's a 4" stroke cylinder
Our CAD is posted on the Chief Delphi thread
A bit more explanation on how the climb mech extends
We have a lot of explanation in the chief delphi thread linked in the video description
Is there a hard stop for the climber to prevent the pipes from falling out when you are going too high?
There is. Unfortunately I don't remember how it's implemented- since it's a cascade elevator it might just be the lowest tube has a bolt through the bottom to stop it once it hits the bushing.
The length of the string limits how far the pipes extend, so by tactful hole placement and string measurement it functions as a hard stop
Why did you choose a 3 wheel drive over 4 wheel? My team is leaning toward 3 wheel and want to know your reasons for choosing it.
We used the KoP Chassis (6 wheel config) because ease of assembly was the main factor for the drive train. Given the length of our robot (32") and the desired 6" wheel diameter (to traverse the field berms), 4 wheels per side would be a tight fit. Having the drive motors in the middle also helps keep our center of gravity in the middle of the robot.
Thank you this was helpful. We were thinking along the lines of what your team was thinking and did a Pugh analysis in which a drive train of this style came out on top.
How did u guys make the pipes go up without rigging it inside
I have the same question
I'll refer to pipes as 1 to 4, with 4 being the smallest. Rope 1 runs from the motor over a pulley at the top of pipe 1, to the bottom of pipe 2. This lifts pipe 2. Rope 2 runs from the top of pipe 1 over a pulley at the top of pipe 2, to the bottom of pipe 3. This lifts pipe 3. Rope 3 runs from the top of pipe 2 over the top of pipe 3, to the bottom of pipe 4. This lifts pipe 4. This is a cascade lift. We 3D printed bushings to hold the pipes centered and reduce slop.
Karl Arnhold thank you!!
How did you build the pvc cascading lift
See the comment replies to kim and Crownos or reference our cad
@@karl_414 thank you
Is the robot able to hold five at a time?
Yeah, 4 + one on the bumper
2:54
What's the length and width of your robot
28x32
What is the material of the hook
The hook is quarter inch aluminum
It’s also wrapped with surgical tubing to make it grippy
Why bother with trench? We're probably going yeet strat through the middle. Unless there's some advantage we haven't thought of.
no defense
We thought with the fast cycles required that having a path with no defense would be very beneficial.
You can't play defense in the opponent's trench. Plus there is a 1 1/8" metal bar that is on the floor bordering the shield switch. Going over that slows down you cycle and has a possibility of shaking things loose on the robot
Another question: what did you guys use to coil the string? Did you guys use a specific type of winch?
We have two winches on the robot, one which powers the telescoping hook deployment mechanism (“the lightsaber”) and one connected to the hook itself which actually winches up the robot to climb. The former winch has a rod with a round exterior and hex interior that fits around the hex shaft of the redline, and has two water jet cut flanges on either side that fit around the hex shaft, which have a hole in them for the paracord to tie to. The redline’s short hex shaft was extended with churro, held in place by the aforementioned round exterior/hex interior rod and a bolt running through its center hole to the tapped end of the redline shaft. The latter winch has a similar setup except with a CIM motor instead of a redline, and there are three flanges instead of two-one in the middle and one on each side, spaced apart with the round/hex rod. The middle flange keeps the paracord running around the right side of the robot separate from the paracord running around the left side, essentially allowing the winch to pull in both directions at once.
If you don’t have access to a water jet, hex wheel hubs tend to make good flanges for makeshift winches.
where do you buy the polycords and pulleys?
They're from West Coast Products.