VEX net controller, battery screw change

We are the proud new owners of 30 new VEXnet controllers (Thanks to Sean and the VEX shipping department for getting them out).

I’m looking at the battery compartment and I’d like to replace the little tiny screw with a thumb screw. McMaster Carr sells ones that should work.

M3— Pitch: 0.5mm
Head: Dia. 9.6mm; Ht. 4.4mm
Length    Part       Cost for a bag of 10
12	96016A054	5.25
16	96016A058	5.38

I’d go for the 16MM long ones. It means that the end of the VEXNET USB key will rest on top of the thumbnut, it pushes it up about 1mm.

Has anyone tried this to see if it’s easier than the existing screw? Or is there an easier access route that I may have missed?

Could you file the end of the thumbscrew down 1mm? It sounds like a small enough distance…

I’m personally looking for an Allen screw to replace it (I never seem to have Phillips head screws around) but finding an English head on a Metric size screw is difficult…

So what I ended up with is this item from McMaster-Carr:

92552A418 Black Oxide Steel Knurled-Head Thumb Screw M3 Size, 16mm Length, 12mm Head Dia, 2.5mm Head High $2.14 each.

The VEXnet key “just” slides over the top of the screw and into the USB connector.

I did try grinding the other ones down, but the plastic breaks. So these more expensive metal ones appears to be the way to go.

We did discuss using the other ones as a way to mark which unit was paired with the controller. The USB stick will not go over them. We decided not to since we though that with enough brute force the roboteers “could make it fit”

glad you found the right screw
our C team just doesnt put in a back plate
if you slam the controller on the desk, the batteries will obviously fall out
but if you use them gently, the it should be fine for competition

and i personally fall under the “can make it fit” category :stuck_out_tongue:

we dont use a screw, we find that the vexnet key holds the back plate on fine

Is it really that big a deal? I really don’t think it is wise to use it without a back plate on competition. Just think about it or watch some match videos coaches and other drivers flailing around, say you get excited and jump. It takes all of 10 extra seconds to put the back plate on and use a screwdriver that you keep in your pocket to tighten the screw and you don’t have to worry.

Just my $0.02

THATS the issue most of us are having :wink:
what if the screwdriver is missing?
and you are one of the few teams at the competition with cortex and cannot find another screwdriver in time?
(some clubs with 10+ teams cannot be as organised as you, you know? ;))

the thumb screw just makes it easier for anyone anytime to replace the batteries

Vexactly! We have 100+ roboteers and I swear we have over 200 sets of hex keys but I’m always getting asked for another set. I’m not up for buying 100’s of screwdrivers.

I did buy extra thumbscrews for when they get “lost.”

And we did think about just using the VEXNet key but didn’t want to risk being in the finals and having it fall apart during the match.

These screws seem like a good idea. We keep the screw driver in the container with the charged AA batteries. When other teams have wanted to borrow the screwdriver I have had to say no, but I do use the screwdriver to open up their controller so the batteries can be changed.

Fun design challenge: Have your students build a rig that grips - and shakes, violently - the robot’s own controller. Have it stop moving if it loses comms. Congrats, now you can test!