Introduction: The Dust Ruffler (Sumo Bot)
Tool and material list
The tools and materials used to construct the Dust Ruffler are very straightforward and easy to acquire. Electronics: Battery pack, continuous rotation high torque servos (x3), receiver, and remote.
- 3x2' sheet of foam core
- x-acto knife or scalpel
- hot glue gun
- 3" lego wheels (x2)
- Ftc omni-wheel (andymark brand)
- Andymark KOP chassis axel bolt
- 5-6" piece of metal with holes in it
- more hot glue
- a growth mindset
Step 1: Body Design and Construction
The fist step after gathering materials of most good competition (especially sumo) robots is the drive base (the motors and wheels). First you need to drill out the omni-wheel so that it can rotate on the giant bolt. step two is to cut a piece of foam core around 6" long and 4" tall (a rectangle) don't stress about exactness, this isn't graded on prettiness, otherwise Colin's group would've won. then find a point on the rectangle where if you place the omni-wheel's center at that point it has around 3/4" hanging off of the foam core and in in the middle longways. make a hole there ( do this by making an X with your x-acto and punching the bolt through. After you have the hole (extract the bolt) make two pieces that aren't as long as the piece, but are the same height. Hot glue those pieces to the edge of the piece with the hole at a 90 degree angle making three sides of a rectangle. After you've done that you'll want to make triangle supports with some of the right angles you've already cut and glue them into the corners (make sure they won't interfere with the omni-wheel once it's installed). you'll then want to make some spacers and mount the omni-wheel. Two squared of foam core with holes the grip the shaft as tightly as possible (we're gonna hot glue the shaft in, the wheel rotates on the shaft, it does not need to move). Then hot glue the spacers on, and you've got 1/3 of the drive base done! The next step is to fasten the other two wheels to the drive servos. The servos had installed on them star servo horns. Since the wheels I chose had six spokes, the servo horn lined up perfectly and all I had to do was screw the wheels directly to the horn for a very sturdy connection. After you do this it's time to mount the servos and build more skeleton! The pictures below are fairly self-explanatory, but here's an explanation nonetheless! Cut holes in the walls of your previous assembly that are sized to your servos and hot glue every part that isn't supposed to move!
Step 2: Additional Skeleton Construction
For further support cut a support beam a bit shorter than the rest that cuts across the entire structure. this will be used for supporting all three wheels! make sure it's snug!cut another shaft hole in it and hot glue it to the walls and the shaft to it after pulling the shaft in as much as you can without putting too much friction on the omni-wheel. then cut two more pieces the same height of the support beam but only the distance from the support beam to the edge of the box. then cut servo sized holes in those but make sure they are spaced in such a way that when glued to the support beam they line up with the servo. And we're done with the drive base! (you can try driving it too).
Step 3: Adding the Arm
For the arm, to start you're going to want to do the exact same thing we did with the other servos, but in a bigger piece of foam core. Once you've got the servo glued in, glue another piece on the end of the servo for extra support the same size and position as the last one. once you have your servo in a block of foam core, trim the block to robot size (I got lazy in the end and just used scissors) and proceed to glue it moderately haphazardly onto the main drivetrain and trim for dramatic effect. After you get it glued to the back support you're gonna wanna glue on a floor. This will make the robot much more sturdy and will provide another place to glue the arm mount. After you've got all this, it is time to move to the top supports. Cut a large square of foam core and cut out a hole for the arm mount, and place onto the top of the bot to mount the electronics onto, and further solidify the robot (noticing a theme?).
Step 4: Finishing Touches
you'll want to just put hot glue everywhere. Literally everywhere that doesn't have to move. Then slap the electronics on the top of the bot, wire up the servos to the receiver, and plugin and turn on the battery pack, and you're ready to go! One last and important thing, however, is the dust ruffle (old-timey word for bed-skirt) that gives this robot its name. glue on the pieces to the front of the bot (you'll wanna trim the front first) and add triangle supports to the back of the dust ruffle! the last step is simply to win. Good luck!