I have to gush here about how much I love the “zip-tie the motors” concept. Thanks to the wonderful mentors on the VEX World Coaches Association Facebook group, I learned a new thing that lots of experienced teams do to make changing motors and gears much easier.
As shown in the image at right, there is a large (white) zip-tie that wraps around the entire motor casing. What you can’t see is that the 8 small motor screws (4 holding on the green cap and 4 on the business-end of the motor) have been removed; the ONLY thing holding this motor together is the zip-tie (a.k.a. “cable tie”).
Say what? Yes, really. It turns out that the zip-tie is very effective at holding the motor together without screws, even given the fact that you can’t get it to wrap super-tightly around the square motor. I didn’t believe it would really work at first—or maybe that it would only work on a motor that’s protected from stresses & obstacles—but the motors stay securely zip-tied even when driving over the starting bar in this year’s In The Zone game.
(I’ve noticed in photos of other people’s robots, that they have the zip-tie around the motor and the piece of metal that the motor is connected to—holding together the “whole package”. As you can see in the image at right, our use involves a zip-tie just around the motor casing itself. I can’t opine about which works better or is easier to use.)
So, why would I want toI do this? The benefits, I’ve concluded in the 1 month we’ve been doing this, are AWESOME. When the motor is held together with screws and you want to change the gears, say, from speed to torque, in almost all instances this requires removing the motor from the robot—even if all you want to do is check the gears for damage. Even in conscientious robot design, where access to the motors is good, it still results in a time-consuming process. And on a robot that has been designed with less foresight? Well, you might have to disassemble a section of the robot in order to even access the motor.
With the zip-tie method, the black cap of the motor stays screwed on to the robot at all times, eliminating the need for gymnastics to reach and remove those screws. To check or change the speed gears, you scooch/wiggle off the zip-tie, and lift the entire motor—except for the black cap—off the robot, allowing lightning-fast changing of gears. (Check out this VEX HAX video with one of our team members showing how it works.)
A few weeks ago my daughter had to change our 6-motor chassis from torque to speed gearing, and in all it took about 5 minutes. Seriously. (Then at our tournament we had various problems, necessitating a return to torque, and voila! another 5 minutes or so.)
You also gain a few seconds when you need to check or change the gears on the green-cap end, plus, you don’t need to go find that special screwdriver.
Want to change out the entire motor? Also simple: take a new motor and remove the black cap entirely and take the screws out of the green-cap end. Then slap that entire piece onto the black cap that is already screwed on to the robot and return the zip-tie to its place (via more wiggling/scooching).
It’s So “Cool”
The last benefit of this method is for cooling down the motors. As one of my girls describes in this VEX HAX video, you can use a can of compressed air from the office supply store (normally used to clean computer keyboards) to spray onto your robot’s motors in between matches to cool down the circuit breaker (PTC) that’s built into the motor.
The most effective way to cool them down is to open them up and spray air on the motor component itself. However, “between matches” doesn’t leave a lot of time for opening up your motors (and during playoff matches, there’s even less time plus a greater need for cooling!). In a pinch, spraying the outside of the motors is better than nothing, but with the zip-tie method, you can open the motor ASAP and spray whatever parts you choose.
In short, we love it.