What parts should I not buy?

I am trying to get my teacher to stop buying stuff we don’t use. What parts should I not buy? Leave your comments below.

I would first come up with a robot design in cad. When you determine that the cad is what you want your robot to be and look like you will have a nearly completed parts list (depending on how detailed you go) already to go

i already have a robot almost finished. I am just trying to stop my teacher from buying things that suck, like steel c-channel and the small 2000mAh batteries

I would try to explain to your teacher that if he waits he will be able to purchase only the parts that are needed for your design, saving the school (or who ever spends the money) money. Other than that I’m not sure there is a lot that you can do

well steel c channels explicitly aren’t bad, my team uses them to test out ideas because its cheaper then aluminum and we use some at points of vulnerability for the base so that the robot is more stable, it also adds dead weight when needed so thats also a plus, and to solve your problem just buy stuff that can be used for your robot(have extra) and once your done just prototype with the parts that you didn’t use and buy more when needed… idk if this helps much because it kinda common sense

Mecanum wheels, period…

lol, yep

I think most people could always use more motors, 3000mah batteries & chargers, and 35-hole aluminum c-channels. If your teacher just wants to buy stuff, I would get more of those.
As others have said, I would figure out what you need and buy it.

There only are a few completely useless things like mecanum wheels, worm gears, accelerometer. Mostly just things you don’t plan on using or already have too much of are useless.

The 3-Wire Servo… Practically no torque; minimal speed; not even heavy enough for counter-weighting robots effectively.

I agree. While they are interesting to watch in action, they aren’t worth the trouble or the money as far as competitions go.

if only they made a mechanum wheels that were smaller, then we could have vectored intake wheels…

Here’s my list:

-low strength chain (snaps easily)
-mechanum wheels (fat, heavy, high friction)
-hex head screws (they strip)
-any and all allen wrenches and safety glasses (you can get better and cheaper ones on amazon)
-zipties, rubber bands, spacers, and pneumatics (check and )
-steel (heavy)
-4" traction wheels (they have literally no traction)
-universal joints (the pins fall out)
-claw kit (vex claws are crap)
-IMEs (they stop working with static electricity from the field)
-accelerometer (they stop working, period)
-latex tubing (non linear stretch, worse durability than bands)

If you are looking for a few things to buy, get 1x2x1x35 c channels, new hax saw blades, new motors, and 25 hole 1by bars. You can always use more.

Good luck!

I think I just got a new idea for a 3d printed roller intake thanks!
I am a bit swayed on the 4" mecanum wheels sometimes since I have had teams have pretty good success with them, and I think it’s a nice classroom tool as well. Of course if we go straight competition logic any wheel but the 3.25" omnis are probably wrong in vex(imo).
Right now every team should be trying to stretch all of their motors and electronics as far as possible before buying new ones due to V5 hopefully coming out soonish.(crosses fingers for 2018)
I disagree about the latex tubing as it’s a nice part to have when used properly, but yes #32 and #64 rubber bands are available at walmart for $1-$2 a pack with no shipping.
Steel is always tricky since it’s a price/weight/structural integrity trade off. Yes aluminum is way less weight, but for some parts such as drivetrains a tower supports steel sometimes isn’t a super bad choice. Now with the 3 hole aluminum though, I don’t think I will ever purchase 5 hole of either piece anymore.
This might be a personal issue, but I hate low strength gears and the green tank treads. Also I really don’t like using chain either unless it’s an intake of some-sort.
Spaces, nuts, small fasteners are way cheaper to buy at a local hardware store or through mcmaster carr etc.
The clutches, black star intake rollers, and battery straps are all pretty much useless imo.
To each their own, parting out a robot from cad is the best way to go, but it would not be fun to only have those items for any quick tournament modifications :).