How do I start understanding building structure on my own?

Hi all,

I recently finished making the clawbot, and I kind of got to see how some parts were applied (e.g c channels, gears, bumper angles), but there were still many parts not used in the clawbot such as (I didn’t expect all of them to be used of course)

  • Plates
  • Bars
  • Very Long Shafts
  • Steel Angles
  • Hinges
  • Rack Gears
  • Intake Rollers
  • Those orange rubber bands
  • Turbo Gear
  • Jumper Clip
  • Washers (They are so thin, how could they possibly be use compared to spacers?)
  • Plus, Pivot, and Angle Gussets (I don’t understand how these strengthen robot joints & connect pieces of metal)

Could any of you kindly give me examples of how these are you used? I don’t only want a description, but examples of how and where they were used specifically in a VEX robot.

In addition:

  • I don’t quite get it when it’s best to put bumper angles, chassis rails, and c channels. Could you please give me examples of place they are used and why the other two would not work in that place?
  • When do you use nylock nuts vs keps nuts, a bit confused
  • When do you use motor clutches vs motor coupler
  • Does someone have a video of a robot utilizing a sprocket and chain?

I know this a lot to ask for, but if maybe even a couple of people could help I would really appreciate it! This will not only help me, but I am starting a VEX Club at a big school and a lot of people have signed up so your responses (with your names taken out) could be a big help to them understanding it too. Thanks in advance!

Try searching “Vex reveal” in YouTube. There, you will find an enormous number of videos of teams showing off their robots. You might want to hit the pause button to examine how they have assembled their robots and how they have used things like the orange rubber bands to assist their lifts, etc. Probably the best way to learn at this point is to simply look at lots of different Vex robots from different games throughout the years.

For example:


@FullMetalMentor Oh wow, this is helpful. But, it’s still really confusing trying to understand the inner workings and explanations . It’s just so complex looking I’m pretty much a noob, haha.

If you want to see every reveal and competition, I update these playlists regularly:
Reveal Watcher -
Competition Watcher -

I will happily share you my design notebooks from the past if you want to get familiar with how robots start being made:
Delta I -
Delta II -
These notebooks were made on a rush though, which is why you can’t build an exact copy of the robot. Here are some pictures of Delta II Scorpion 3 in the making (Wasn’t added in the design notebook though):

Take a look at exactly how everything is placed and how all of the pieces that correspond with eachother. When creating a drivetrain, it’s best to have at least 2 C-Channels that go across(As shown on the top pictures). Any less will mean your drive is very unstable. Triangles are useful as well when creating a lift, so attach a beam at an angle towards your “tower” or the thing that holds the lift. If you have anymore questions, I can happily answer :slight_smile:

Just my experience:

To start, most of the clawbot parts actually arent ideal for competitive robots. The metal is steel, which is heavier and not much stronger than the aluminum c channels and angles that VEX sells, the screws are the black ones, which strip easier than the silver ones VEX sells, the gears are low strength as opposed to the high strength gears VEX sells, the wheels are traction wheels instead of the omni directional wheels, which reduce skidding and make turning easier, etc.
Chassis rails are useful for small steel components where strength is important, but aluminum chassis rails or c channels are good for the drive base. Use the long metal for the drive base for best stability. Use aluminum for the arm so the robot isnt top heavy. C channels are more useful than angles in general imo. Plates arent often useful, but you might find a good use for them.
Nylock nuts stay in place better in areas where vibration occurs while keps are easy to prototype with and are slightly lighter.
The pop rivets that go on the bearings in the clawbot kit fall off very easily, so you should use screws and nuts instead to secure bearings.
Sprockets and chain are good to connect moving parts over long distances or if they have to go in the same direction. Sprockets and chain are great for drivebase wheels.
Gussets are handy in creative applications, but arent necesary often.
Clutches and couplers aren’t necessary with VEX 393 motors. Just push a shaft into the motor directly. Transfer power by putting a gear or sprocket on the shaft that goes into the motor and connecting another gear or sprocket on a different shaft to the other.
Long shafts are typically used to connect two sides of an arm, or you can just cut the for other applications.
Washers are just mini spacers. Put them in places where there is a little bit of space left but not enough to fit a spacer, or use them to make a compact joint.

If you have any other questions, feel free to ask or PM me.

I could use this too:
YouTube Channels someone just suggested to me

To clarify, the clawbot kits are still worth the money you spend on them. The dual control kit pays for itself in just the cortex, battery, charger, controller and motors, plus you can still use certain parts like bearings, screws, nuts, collars, etc.

A great source of information on Vex structural parts is the Vex Inventor’s Guide.

@Bryan R
Thank you for your responses What are the following used for, could you give me some quick examples please?

  • Anti-Slip Mat (2-types)
  • Adhesive foam
  • VELCRO® Brand Adhesive Strip (5’)
  • VELCRO® Brand ONE-WRAP® (5’)
  • Robotics Engineering Notebook --> Can we just use any notebook ,do we need to buy the official VEX one?
  1. Anti-Slip Mats: Cuttable and compressible high friction mats. Use for adding grip, friction, or padding.
    Usually in VEX, they can be used for both keeping things from slipping as well as it can use as a “shield” to block game elements from going into important areas. Example:

  2. Adhesive foam: 1/4” thick foam with adhesive on one side that can be used for robot bumpers, vibration isolation, accumulator backing, and any other applications requiring compressive padding. Basically it can be used for a dampener as well as stop vibrations. (Btw Anti-Slip mats can do a good job as well). They can be really useful for linear punchers and catapults in the VEX year Nothing But Net.

  3. VELCRO® Brand Adhesive Strip (5’): This adhesive VELCRO® Brand product has an adhesive backing so it can be attached directly to metal to hold a light weight object like a battery, create a trap door, or build a detachable part. It basically is used for things that can detatch if needed. One thing I do prefer when using VELCRO® is by using them for easy detachable license plates.

  4. VELCRO® Brand ONE-WRAP® (5’): VELCRO® brand ONE-WRAP® consists of 5 feet of our 0.75 inch wide VELCRO® brand ONE-WRAP® that can be used to attach a light weight object. This Wrap comes with Hook on one side and Loop on the other so that it attaches back to itself for a secure closure. Usually these are great for wiring reasons, but usually they aren’t truly needed.

  5. Robotics Engineering Notebook --> Can we just use any notebook ,do we need to buy the official VEX one?: Whenever you register your team for the season at, they will ship you various items as well as a VEX engineering notebook. VEX usually prefers that type, but they can prefer others.

Hopefully this helps! :slight_smile:

  • [TVA] Delta III

what he said.
The anti-slip mat comes in two thicknesses, which just changes the amount of traction. The higher traction version is more durable and won’t slip as much.

It can be very overwhelming to look at every part and see that you’re not familiar with many, but that shouldn’t prevent you from building! When I first started vex, I just looked at all the major categories of parts to make sure I understood their function. Then, I started building my robot, and when there was a specific piece I needed, I could know immediately whether vex sells that sort of part.

Many parts are useless. I would argue steel, light and usually ultrasonic sensors, thin friction matt, low strength 12 tooth gears, mecanum wheels, 6" intake rollers, and many more parts should rarely or never be used. In any case, the major components of your robot will be c channels, spacers, shafts, screws, nuts, gears, motors, bearing flats, and wheels. This is only 9 kinds of parts! Once you start building, you will become familiar with specific applications of other kinds of parts, and you can go from there.

Finally, copy other good teams. Not necessarily screw for screw, but copy their general idea. In NBN, I spent an absurd amount of time pouring over reveals and such to base my robot off of, and ended up not qualifying for states until early February after 4 failed attempts. I then went on to win states and lose in the division finals of nationals after going undefeated in qualifying matches. Point being, you won’t be good right away, but you will become good over time by building and rebuilding. You don’t need to have a perfect understanding of every part up front to dive in and start.

Stay active on the forums, check youtube, and start building! You’ll be amazed at how much you learn by actually doing it. Good luck!

@Anomaly You are definitely right, I’m starting a high school VEX EDR Robotics club and although at the start it does seem daunting, before I saw this message I had made a nice list explaining each part, so at least I understand most parts (although I will heed your advice and not focus too much on advanced gears, etc). I will keep on trying, I have three years to learn!

Sounds good, kick some butt!