VEX PD+ Live Sessions: Engineering 101

[Matthew_Goodwin]

Hey @Molly_Gomes thanks for being involved in last night’s session, and providing all the helpful feedback both here and in the other thread. I’ll be responding in this thread in regards to the Engineering 101 Session, so please let me know of any other questions/comments.

@Molly_Gomes

Since you can use a max of 88 watts on the robot, you can use up to 8 11-watt motors or up to 16 5.5-watt motors. Basically that means you can trade a single 11-watt motor for 2 5.5-watt motors. That allows you to have more of those low-load motions, and you can save the 11-watt motors for high-load motions.

The new 88W rule allows for any mix and match of motors as well! I’ve attached an image from the game manual explaining it much better than I did regarding possible motor combinations.

@Molly_Gomes

Matt also demonstrated how to use the these motors in tandem with pneumatics on the Striker Hero Bot. You can attach the triball intake to the chassis so that the pneumatics can push it out over the triball. Am I explaining that correctly?

Close! I showed an application of using the 5.5W motor on the intake of this year’s Herobot Striker. Pneumatics have been used in previous years’ games as another way to actuate mechanisms. With the new motor rule, teams can utilize more motor actuators on top of utilizing pneumatics, just to add another layer of complexity and customization. While I did not have any pneumatics on last night’s bot, incorporating them with the 5.5W motors would be really cool, and you could definitely do what you explained!

@Molly_Gomes

• Would two 5.5 motors working in tandem have a stall torque of 1.0 Nm?
• Could you do an example build of a compound gear train with the 5.5 watt motors? Something like the V5 STEM Lab: Mechanical Advantage
• I would love to see some VEX Library articles or example builds that incorporate pneumatics. We have a single acting and double acting cylinder. We can make them move with the help of this VEX Library article, but are still struggling to see how to connect them to the robot properly.

1. Yep, two combined 5.5W motors (either through a shared shaft, gear/sprocket/chain train) would basically have a stall torque of 1.0 Nm as they’ll work together. You’ll note this stall torque is still lower than a single 11W motor’s stall torque of 2.1 Nm. This means it may be worth it to just use one 11W where you may be considering combining two 5.5W’s. Here is an article from the VEX Library all about information regarding the V5 Smart Motor (11W).
2. Yeah I can work on something similar to that! For the time being, it would look very similar since the biggest difference would just be the motor change. I had this simple 3D build laying around for you to look at for more reference of a gear train utilizing the 5.5W motor in the meantime.
3. Absolutely! Thank you for this feedback, as we can definitely create something to aid you in connecting pneumatics properly!

@Molly_Gomes

I would like to learn more about using the sensor data that you see on the devices screen while running a program.

This is also a really cool idea. I’ll continue to brainstorm over ways we can incorporate this and show off fun stuff. Not only is it important to conceptually grasp why the robot is doing the thing it’s doing, but being able to see the math involved when it is doing these things would provide a much deeper understanding! Thank you for all the feedback you’ve provided, and I hope my message was of any assistance! We’ll be posting a recording of the previous Engineering 101 course soon in which we covered the motors, but in addition to that here are the slides that I used from last night. Let me know if there is anything else we can do!