i Want to make a side roller bot and I am wondering if it is legal to use zip ties as the flaps to grab the cone.
It is perfectly legal
As I understand the rules, you can use zip ties for mechanically functional things (like flaps, etc.) so long as they are identical to the ones Vex sells. Zip Ties - VEX Robotics
However, other types and sizes of zip ties can be used for securing electrical wiring as per rule R<7> L, which states, “Commercially available items used solely for the purpose of bundling or wrapping of 2-wire, 3-wire, 4-wire cables, and pneumatic tubing, for the purposes of protection, organization, or management are allowed…”
I wanted to add that stipulation so you would not use, for example, extra large or extra small zip ties for a mechanical application and find out they are not allowed except for wiring applications.
Thanks for this