Since 2011, MARS has built its practice “beta” robot slightly ahead of schedule of the construction of its competition “alpha” robot (allowing us to identify issues and fix them before construction the alpha robot). This year’s beta robot is taking shape and is (almost) ready for a weekend of testing and improvement!
Some Details:
-Dropped center 6WD, 2-speed transmission geared for 5ft/s and 17ft/s.
-2 wheel linear shooter.
-360 degree rotating and tilting turret.
-Load disks from feeder station, YES.
-Floor pickup, YES.
-Fit under pyramid, YES.
-Level 1 hang, YES.
-Level 2 hang, HOPEFULLY (it’s designed but we won’t know for sure until we do some more testing ::safety:: ).
This is a very pretty bot, though I still don’t see the frisbee pickup or shooter. I guess that’s all in construction? Can’t wait to see it run!
The Colson’s are 6 inch. This is the first year we’re using them and we’re excited to try them out at competition!
Correct, the shooter transmission and wheels are not yet mounted and neither is poly cord or the front part of the floor capture device which makes it kind of hard to see those subsystems in the picture. You can see them in the CAD though (you might have to squint to see the shooter wheels hiding behind the shooter rails in the CAD )
It’s a bit hard to tell, but it doesn’t look like there’s enough space for four frisbees in the ground pickup. Is there some way that frisbees are fed back into the human load chute on top?
I agree with this. It appears that the turret would turn 180 degrees from its position in the CAD render and then would tip to allow frisbees to directly enter the shooter barrel from the intake. I am still puzzled as to how it can hold 4 frisbees between the intake and the shooter.
The intake is interesting, because it appears that frisbees would slide onto that plate for a few inches before contacting the roller.
Can you provide any details regarding the wheel mounted between the shooter and the frisbee hopper? Could this be part of your level 2 hanging mechanism?
You are correct about the shooter tipping down in order to receive ground disks from the capture device. The Frisbees then travel to the rear of the shooter where a mechanism (which you can’t really see) loads them up into the the hopper. As you might imagine there are quite a few moving parts to the ground pick up system and in general we plan to load from the feeder station. The ground pickup capability is mostly for autonomous.
I believe you are seeing the wheels which help feed the Frisbees down from the hopper into the shooter (similar to the wheels on Robot in 3 Days).
I just love that time of year when I get to see what cool designs other people have been working on…
I was especially excited to see the intake. Besides the obvious (climbing), pickup of frisbees is the most chalenging part of the game. It looks like you’ve found a solution that works for you, we just never found a way to pick up frisbees that was satisfactory fo us.
This past week was mostly spent working out kinks and bugs, iterating some designs, and implementing those changes as the the alpha robot went into production.
(Apologies for the poor video quality)
Loading the shooter via a full magazine was tested (although the code for the fully automated sequence is not yet complete).
The first successful level 1 hang was completed (it is fully off the ground in this video but we are missing a disproportionate amount of weight in the front so in the final iteration the hang will be much more balanced).
The latest iteration of the floor grabber was tested (we understand what changes we have to make to get the Frisbee to more reliably travel up the rest of the feed system).
The alpha frame is back from being powder coated and was stuffed with electronics last night.
And here is a slightly updated CAD render (the biggest difference is the new level 1 hook design)
We have also tested feeding the Frisbees backward through the shooter and into the breech and of course the pan and tilt functionality of the turret has been tested (sorry, no video at the moment but I’ll try to get that up over the weekend). Additionally, excellent progress is being made on the level 2 stage of our hanging mechanism.
That floor intake is very similar to ours. I have a quick question though. What we’re finding is that with our system, an upward force is placed on our intake system when the frisbees attempt to enter and angle upwards in the intake system. How are you guys absorbing that force?
(The idea behind the force from what I understand is that the frisbee is not compressible, and you can only rely on friction to bring it in. )
The upper roller on our system is pretty robust, so even if the frisbee forces it upwards, and off the floor, it doesn’t bend. The shallower the angle, the better of course.
We have an open house tomorrow and we will have more pictures and video of our alpha (competition) bot then. But we figured we’d just leave these here for now
Testing shooting from the feeder station (we forgot to put in fresh battery so it starts to die toward the end).
Level 1 hang
We decided to go all out on the LEDs this year
Keep your eyes open for more about Marvin VI And good luck to everyone in these last few days!!
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