VEX Over Under 81988E Extropy Robot CAD

Hello all!
Our team is proud to present our two Ri3d robots for Over Under!

The first robot is the skill competition robot that has been made public last time.
Details: 81988E 299 Official Skill Challenge and CAD picture - #7 by Orrero_yang

It has almost all the functions needed for Over Under, except climber. However, an A-level climber is very easy to add to this robot.

The second robot is also a Ri3d robot, which is a new design we made for the team competition on the basis of the original one. The Cata structure is deleted, a B-level climber is added, and the Chassis is upgraded, which consists of 360PRM 3.25in wheels It has been upgraded to 300RPM 4in wheels, which makes it easier for our team robot to operate at high speed in the field. We have also optimized the intake to make the intake of this robot score more smoothly.

  • 66W 300RPM 4in Chassis
  • 11W 300PRM Intake
  • 11W 14RPM Climber

We have continued the previous frame design. There is no big difference in appearance between the two robots, and the assembly is relatively simple and easy to make.

Public CAD Model for Solidworks: 81988E_Extropy - Google Drive

If there are any questions about the robot, feel free to post them below!


I like the designs.
If you ever build this would you post it?

They already have! This robot is sick, take a look!

How is the brain mounted?

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Would you guys mind showing how you did your slip gears?

We use two screws to fix it on the side of the brain.


We use a bench grinder to make slip gears.
27t was cut off from 36t and 9t was retained.

why not do a double slip if you only need 9 teeth?


We tried double gears, but we used a 36:60 gear ratio and it wouldn’t run at full speed.

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