Defective Parts

Sometimes we get parts that just don’t work, and this goes beyond motors or VexNet keys. Here is a picture of a 1x2x1x35 Steel C-Channel that we got in our latest shipment:

Notice the hole in the bottom left which should be there but isn’t. The right one has been used before, the scratches and stuff were caused by use.

What kind of issues has everyone else had with parts straight out of the box? Often they’re pretty small issues that don’t justify RMA-ing the parts and getting new ones, so they go unreported and Vex probably doesn’t even know about it. In this case we didn’t bother RMA-ing it but it was still a bit annoying when we tried to mount it.

Does Vex need to improve the quality control processes, or are these just really really isolated incidents that are only affecting a really small number of teams? If you’ve had issues with parts straight out of the box before, post below (probably better if you have photo evidence) - if it IS a big problem, then maybe some action needs to be taken; if it isn’t a big problem, then feel free to ignore this thread.

we had some aluminum come out of the box with some “dents” just like the right c-channel above
but it was hardly noticed
i have never seen your left c-channel though
how deep is the indent?
did you try “punching” it out?
or maybe just drilling it will work

Yeah we’ll get a hammer and a screwdriver to see if we can just punch it out, but it’s still a bit annoying.

Here’s another one: Rust on axle out of the bag.

Some rust on 1x25 Steel Bars out of the bag.

Like I said before, it’s not a MAJOR issue, and it’s not worth RMA-ing and such, but it’s still a bit annoying to get parts like this.

Andrew, we had a problem 3 years ago when we ordered more Pics & remote controllers. One of the remote controllers came in a really banged up styrofoam box & we knew it was used because it was missing the straw for the antennae & the receiver to mount on the robot, not to mention the broken pieces of styrofoam and ripped off tape. Called VEX & they were very concerned about that & had us return it so they could check into how that happened & shipped us a brand new one. Perhaps you should notify them so that the issues can be resolved. :slight_smile:


During clean sweep we had a bag of metal bar locks come in that would simply NOT fit on any axels. All the pieces were warped just enough to not fit. Other than that one incident though, out of 4 years of Vex, my team has never had any issues. Vex does a good job with their products.

I have always found the lock bars to be a really tight fit. I have actually been unable to remove some of them… I think they are designed to be really snug.


Also found a new motor today that seems to have reversed internal wiring. Two motors, in exactly the same position with the same external wiring to the cortex using the same code, spin in opposite directions.

We have gotten metal that was warped around some of the hole. (flatened in places. re-punched maybe?):confused:

Luckily that is a very easy fix. Just plug one in backwards into the Motor Controller 29. Unlike PWM, you can just reverse 2 wire motor direction by plugging it in the other way.

Contact VEX directly and they can set up a return for you. This shouldn’t be happening, obviously, and they would like to know about this kind of problem.

The teams I mentor have had this happen, and we think it is a great benefit. We bought a cheap, tiny diamond file (I think it was about $5) and used it to enlarge the square holes a tiny bit, and we ended up with the snuggest-fitting lock bars of all time. I actually prefer the lock bars with the slightly-undersized holes. I think this is what we use.

(Actually, when this first happened I called VEX to exchange the parts, and it was one of the VEX support guys who suggested filing. It sounds like a work-around, but I truly believe we get a better fit this way.)

I agree, It is great to have parts with minimal wiggle room especially for shafts that end up going to sensors. At the beginning of last season I had issues with the potentiometer on my arm due to the axle slop in the 84 tooth gears. I was able to remedy the issue by attaching a really snug lock bar to the gears.


I would agree with you both that having very snug bar locks is beneficial. In hindsight, we might have been able to use a file as suggested.

In at least my experiece though, normal non-warped bar locks are usually snug enough, though not always.

I will keep in mind the file idea though if this should ever happen again. :slight_smile:

Thanks Rick! The problem for us is that we’re in New Zealand, and the cost of returning the products (shipping and so forth) is prohibitive if we have to pay it given the size of the problems - we can fix most of these problems very easily.

We’ve punched a hole into the c-channel, filed off most of the rust on the steel parts, and just made a note on the motor to reverse the motor controller (although someone will undoubtedly forget in the future and get confused about why the motor isn’t working again), but it’s just a bit annoying and we were wondering if it was happening in a lot of places with a lot of teams or if it was just us. It seems like it’s a pretty small problem, so Vex probably doesn’t need to improve their QA or anything like that; we just got really unlucky.

previously we have had vex net keys that dont work and at a competition one of the new joysticks (brand new maybe 3 weeks old) stopped working (the firmware erased its self???(we fixed it by re installing the firmware)) unfortunately it got us knocked out of the competition in the semifinals after qualifying 1st and being undefeated besides those 2 matches. it works fine now but it was a major disappointment to us. we were already qualified so it didn’t effect our trip to the world championship but im still hesitant to use that joystick for anything vital on our robot (it previously controlled the drive)

I got 2 packages of stand offs that were not machined. Had to hand crank in the screws to machine them manually. Not worth the price or headache of returning for new ones.

If you receive a part which is clearly a defect in manufacturing, PLEASE let us know. In most cases we will be able to “take care of you” to make things right.


I was doing this for quite a while too with barlocks, until i discovered it was actually our shafts that were a problem rather than the barlocks…
Anyone else have shafts too thick to fit into motors?

I have one like that (but, then again, it might be a bend in the shaft)…