Відео

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

They're just mounted with adhesive-backed Velcro which lets us take them on and off without too much trouble.

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

It's paracord

4"

We have a lot of explanation in the chief delphi thread linked in the video description

Nope. It's entirely driver controlled.

The climbing winch is 2 CIM motors on a 24:1 reduction and a 0.7" diameter pulley

Peanut Tube: www.andymark.com/products/peanut-extrusion-different-lengths-options

1 inch compression

The shooter spins at about 4600 RPM. We should have gone faster to get in the inner goal.

The bumpers aren't part of the overall frame dimensions. The frame itself is approx. 32x27, which fits inside the 120" perimeter

We'd be happy to find someone who can help you out! You can get in contact with the University of Minnesota robotics team by email at robotics (at) umn.edu, but I would also recommend you contact the MN FIRST regional leadership to get in contact with a local team or mentors that have robotics experience: firstuppermidwest.org/contact-us/

We used modified pvc T junctions to mount pulleys for the bottom two stages, as well as cut notches in the bottom of the pvc pipes for the paracord knots to rest in without rubbing along the pvc.The inner diameters of the pvc tubes on our final version were 0.5 inches apart, giving the paracord some space even with the thickness of the pvc.

​@DeltaForce3537 Here is a picture showing what we did: lh5.googleusercontent.com/qzSFJsTDLL8L1TY530Y2b9697Xhgx3k9vywS4c2pZTg7FED4jZSopWVjvSN5guKeTIbw2oiSJpUSxxgcjCyzVPYxH7ABGouIH06FNelgS-E3ss7wPek=w1280 The red lines are cuts, the scribbled out part waste material, and the blue circle is where we mounted a bearing inside the T junction on a bolt across the diameter. There are, I'm sure, many other ways to mount a bearing and/or reduce friction, but this functioned fine for what we had available.

@DeltaForce3537 Ah, apologies for the link issue, I will describe as best as I can (please bear with me if I am describing things that are obvious; it isn't particularly complicated, I just want to make the description as clear as possible). The unmodified PVC T-junction is, unsurprisingly, shaped like a T and can connect up to 3 PVC pipes by fitting them snugly into its channels. We rotated the T-junction 90 degrees so that it looked like a sideways T (kinda like "||=") so that there is a channel going to the bottom, a channel going to the right, and a channel going up. When I say "bottom", "top", or "right" in the rest of this description I mean in this "||=" orientation. We modified it by cutting off the top channel of the T-junction, making it look more like an upside down L, and then used the right channel to mount a bearing. We did this using a bolt running through the diameter of the right channel and some spacers (we eventually 3D printed them but cut up surgical tubing actually worked pretty good for our prototypes) to keep it centered. The PVC pipe for the stage will go in the bottom channel, and the rope will run around the bearing so it isn't rubbing along the bare PVC end. If you plan on going underneath the trench or are worried about height for another reason, cutting down the upper left part of the T-junction to make space for the T-junction of the next stage to nest will help reduce height and bulkiness. You can then have one T-junction pointing to the right, the next pointing to the left, etc if necessary so that they can nest easily. Hopefully that description helps! Best of luck to you and your team

The winch is made of a rod with a round exterior and hex interior that fits around the hex shaft of a CIM motor, and has three water jet cut flanges that fit around the hex shaft, one on either side and one in the middle, spaced apart by the aforementioned round exterior hex interior rod. The flanges have a hole in them for the paracord to tie to. The CIM's short hex shaft was extended with churro, held in place by the round/hex rod and a bolt running through its center hole to the tapped end of the CIM hex shaft. 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.

The gearbox for the winch is an old andymark one. Any one with about 15:1 and supports two cim motors should work

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.

The winches are all coiling around Andymark metal spacer stock. The end plates are waterjet cut.

We don't have a scale, but I would guess it's on the high end of the limit ~130lbs

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)

Looks like surgical tubing wrapped tight around a hook

It is indeed surgical tubing

Karl Arnhold thank you, and where did you purchase this surgical tubing?

@@jonathanbacon3248 You can get it on McMaster: www.mcmaster.com/surgical-tubing

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.

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.

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!!!

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

They're from West Coast Products.

We use pneumatics to actuate the intake (0:13) and the control panel spinner (1:46), and to stop balls from entering the shooter (0:25). They are a relatively simple way to actuate mechanisms that have 2 fixed positions. You will need space for the compressor and air tanks, and will have to watch out for leaks.