Picture a standard 18x18x18 box with a drive train. The triangular prism inscribed in the cube represents a conveyor belt, similar to that of AURA’s Java bot. The prism is held on linear slides/rack/pinions and can be raised up/down to score in the different height goals.
Intake is from the left side when the prism is all the way down. Basically the robot can drive over objects and suck them up like a vacuum.
If the goal is 18"+, the robot will score from the back.
Any goals under 18" can be scored from the front.
I also know of a team with this design and they are doing quite well. Team 3129A Green MacHHHHine has parallel treads and a vertical lift powered by two chain lifts (one on each side of the robot) that is quite fast. They have already qualified for worlds three times (two excellence awards and 1 tournament championship) and are in the top 10 in both robot and programming skills.
You don’t necessarily need to put a lot of dead weight or use a lot of motors. It can be fast if you design it well.
I didn’t mean you had to literally put a lot of dead weight. I meant it IS a lot of dead weight (on the entire robot in general). I’m currently trying this idea too but I don’t have enough chain to make a chain lift. I’m settling for rack and pinion for the time being.
Our first design was similar to green machine, shown at the McKinley VEXhibition. We had the same lift mechanism, however all our 393s were on the lift. We placed four 269s on our chassis, and the rest on our intake (lost the first matches due to a friction problem → overheating), but other than that, it was a good design. We were able to score the 11 inch and the 20 inch while facing forward, and all goals while facing backward. Our weight, was about… pretty heavy (can’t give an good estimate, but definitely a heavy robot due to the linear slides)
This design was retired, due to many overheating problems (intake and drive) and inspiration from other teams. We weren’t able to get it working as marvelous as the green machine; kudos to them.
Was your lift built using linear slides + high strength chain? I’m wondering how well rack and pinion will work. I remember Green Egg robotics did a rack & pinion design with high strength chain to lift the goal posts in Roundup.
I currently have 4 393 motors on my drive train, 2 269 on intake, and plan on using 4 269 on a lift.
I’ve found 4 393s geared internally for speed (1.6:1) and then 1:1 to wheels were perfect for a competition. We could skirt around other robots or push them if we needed to (if the refs would let us).
They used 4 269 motors on their lift, 2 for each chain lift on each side. I suggest not using the rack and pinion gears, they are much slower than a chain lift and are much less reliable.
hears a video of team 3129A (green machine)'s robot. Their pretty good considering their skills scores, and that they won this tournament, robot & programming skills, and excellence.
Our lift was inspired by 1103, so it consisted of two dual stage lifts (lots and lots of weight) and chain. We did not decide to use the rack & pinion because of the height limit (may be different now with those new slides).
We tend to overbuild sometimes, and used eight sets of slides for the entire lift (this was why it was so heavy). With this being said, we had to use the 393s on our lift (we wanted lift speed as well), and did not focus on speed on our drive. Your setup was our initial setup, and as long as you build light and right, the setup is fine.
I’m building mine similar to how Green Eggs built their goal post carrier. They used a metal pinion attached to high strength chain to push their linear slides up. I’m now looking for a different lift because GER’s lift can theoretically only go up to 32" (18" * 2) but with a little bit of room it’s more like 28-29". Still not enough to score on the high goals. 1103’s lift is clearly better but I do not have enough high strength chain to make one.
It does depend though, you could score the 30" from 28" if you do it right, because remember that the intake has force behind it could bump it up and over (not sure about the tread design, but my WC robot only reached 29")
Because it is pivoting, you can do it on only 1 269 on each side (means either super fast tread of super powerfull/fast drive because it uses less motors) on 1:7
Reaches 30" very easily, i think the one in the photo reached 35 ish
you dont need to worry about accidentally spitting objects out the back when you pick more up
The only disadvantage i see is stability, which really isnt an issue when you dont have a 6 bar etc, because the weight isnt moving forward/back a great amount
The big problem with lifting to only 28" or so and “popping” the objects up and into the goal is that it can very easily be blocked by a robot with a higher reach. Last competition, we blocked numerous double pivoting tread designs by parking our accumulator on the middle 30" goal so their pieces just bounced off.
