675B Robot Reveal

VEX V5 General Discussion VEX Robot Showcase
#1

Sorry, mine’s a bit later because I’m on vacation and a mobile hotspot isn’t the most reliable thing in the world.

This is 675B’s robot this year. I apologize for the slightly unprofessional pictures - we didn’t have a high-end camera to use for them.

https://vexforum.com/gallery/files/4/1/6/3/0/8/dscn1253.jpg

https://vexforum.com/gallery/files/4/1/6/3/0/8/dscn1247.jpg

https://vexforum.com/gallery/files/4/1/6/3/0/8/dscn1257.jpg

And these are some pictures of a slightly older iteration of our robot. Since then, our arm has been strengthened and the ultrasonic sensors removed, along with the back support. It works much better now. However, the maneuvers are the same.

https://vexforum.com/gallery/files/4/1/6/3/0/8/20130131_161547_6.jpg

https://vexforum.com/gallery/files/4/1/6/3/0/8/20130131_161657_16.jpg

This robot features:
4 x 393 High-Speed motors 1:1 on the drive
–Chained together to help with stalling problems
–Chained to encoder with smaller sprocket for more precision
4 x 393 High-Strength motors 3:25 (torque) on the arm
–Large gear surface area for minimal loss of contact
–Gears screwed together for minimal axle shearing
–Unique gear ratio provides a more ideal speed-torque ratio than similar designs (slightly but noticeably faster arm)
2 x 393 high-Strength motors 1:5 (torque) on the scoop
–Reinforced (mechanically) solid piece of 1/16" polycarbonate, 17.5" wide, 9.5" long for maximum strength and surface area

Additional Features:
–Pneumatic support on back to aid in descoring as well as preventing the robot from flipping (can be disengaged and reengaged in case of actual flipping)
–2 x real-time Potentiometers used in conjunction with PID to give set angles at any arm height as well as maintaining the same angle as the arm raises/lowers
–Lots of nifty programming features that aren’t visible at all
–Potentiometer autonomous selector
–Handles!!!

Performance
–Average of 45 Autonomous points
–Average of 190 Robot Skills points (we’ve not had much practice :P)
–A pretty awesome Programming skills run, though it’s definitely not the highest scoring

This robot is capable of:
–Driving under the trough
–Quick and massive trough descoring under the right circumstances
–Trough scoring in the matter of a couple seconds
–Picking up 12+ sacks in a single load (we prefer not to strain the robot though…)
–High goal scoring
–High goal descoring
–Scoring backwards into the trough
–Something special we’ll share after World

This robot has won:
–1 Excellence Award
–2 Tournament Champions
–Competed well into the elimination rounds in 2 other qualifiers

#2

looks great. What do you use the ultrasonic sensors on the lift tower for?

Thanks!

#3

I’m sorry, but as someone who has OCD episodes from time to time; why is the cross bar no your lift arms not square? That bothers me and I’m not even driving it.

#4

We originally had them in case our driver(s) was not thinking and put the arm up/down while under/over the trough (this happened before…), but they proved too unreliable and the driver(s) got better. They’re not on the robot now, as evident by the first picture.

I know, it bothers me as well. But the spacing of the arm beams are at such an odd distance, is not even at 1/2 a hole. Placing it angled like that is a sturdy and simple solution to the problem, at the expense of people’s sanity. :slight_smile:

#5

Why don’t you just use a drill and make the holes bigger to make it look square? Also do you tip back every time you try to descore, because I have a robot close to yours and we don’t tip.

#6

We try our best to not modify parts to make them as useable as possible for the following year. In fact, we had to buy those parts and cut them to that size already. And if it works, why fix it?

And we only tip that far back if we don’t do one complete motion. We did that photo one slowly, to demonstrate the process. We actually use the tipping to have the robot weight as a force behind the scoop digging into the trough. We technically don’t need to make the descoring that low, but it’s a lot stronger this way. However, this never presents a problem with the robot falling over, even without the back support. We only tip if our arm is vertical and we are pushed vigorously, or our arm is completely backward, both assuming our back support is folded in.

#7