Hex nuts are probably the least secure as they easily fall apart. But what about nylock and keps nuts? I know that Nylock is secure, but it’s consumable. And hard to work with at times. I think since it’s still early season that keps nuts would be better. But how are they more secure? Do they achieve it by grabbing onto the metal with its teeth? And how does it’s secureness compare to nylocks?

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hex nuts is just the shape, but I assume you are referring to the plain ones. Keps nuts do grab the metal a bit more but aren’t noticeably different. They are good for quick prototyping. For any other use you’ll probably be best with nylocks since they don’t come off unless you are seriously trying to break them.


Do you know where I can get large bulk amounts of nylock nuts?

As far as I know you have to get them from vex or its resellers to be competition-ready. (Identical parts should also work but idk where you’d find those)

Be sure you check out the game manual for specifics

One thing I must say for keps and hex, in my time in vex, I have personally found hex to be stronger than keps. Why? Because the little bearing type piece that allows the keps nut to bite the metal also keeps the nut from really completely touching the metal. Because of this, over time, the keps get loose and fall off. Now this does still happen with hex nuts, but I have noticed it to be very minimal. Now something that never comes off would be nylocks.

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Check McMaster-Carr and similar distributors. also has some items that may be of interest to you.


Originally I built with keps because you only need a wrench to tighten instead of the whole time your screwing something in, but after a while building I got used to using a wrench and realized my laziness cost more in the long run when things came loose. Now it’s exclusively nylocks. I use keps for joints in very specific circumstances but nylocks are the way to go.

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You can just use your fingers to hold keps nuts in place and eventually the friction stops it from turning so you dont need wrenches.

Even so, if your using a keps joint the point of the nut is to attach the screw but also prevent the screw from turning (advantage of keps joints is there’s less friction because only one part turns instead of both) so after screwing to friction tight it’s best to crank it down with the added leverage of a wrench.

For all my car people out there yes a torque wrench is overkill in vex👀


Never fear my fellow roboticist. The best kind of kill is overkill


nylock is strongest because of the nylon doesn’t have threading and just grips onto the screw, but considering the fact that they can be almost impossible to get off half of the time, i would suggest hex and keps since they aren’t actually bad at all and haven’t fallen off for our team yet.

If there’s a flywheel, use nylocks. Vibrations kill hex and keps.

Side note try not to reuse nylocks more than I’d say 3-5 times max. They do wear out and become fancy looking hex nuts over time.

For most applications, hex or keps nuts are a better choice than nylocks. And again, as people have mentioned before, keps and hex are about the same as far as grabbing force, you just have to make sure to tighten them correctly. Personally, I prefer the hex nuts because the spacing is better with them. Both of these are very good for about any structural piece that isn’t on a rotating joint. they are also lighter than nylocks, which is an added bonus. They are best used in bracing, screw joints, and similar applications. Nylocks are best used on screw joints and occasionally in places with excessive vibration and where it would be extremely difficult to replace a screw.

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I’d respectfully disagree. With the exception of screw joints, I think nylocks are better than hex and keps. Grant it nylocks are heavier and more effort to apply, but they’re much less likely to come loose, making them more reliable and in my opinion reliability always outshines ease of use.

Ultimately tho teams have been very successful using all kinds of nuts, and your choice of nylock vs keps will not make or break your robot as long as everything is properly torqued.

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I personally use nylocks wherever I expect there to be rotational force. Ex: A brace, the end of screw joints, chassis. I use keps wherever I can sink the teeth into plastic (such as bearing blocks) or where I need to conserve weight (lift structure). When I use them I typically use the locktite .5" star drive screws, as I can tighten them down hard, which digs the teeth in, and the locktite will further insure the kep stays in.
By the way, I really recommend a ratcheting hex set. It makes tightening nuts, especially on screw joints, a breeze.


Um, I might be mistaken, but wouldn’t those be keps nuts?

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But the teeth wouldn’t they also scratch up the surface?

I don’t really think that matters, unless your going for the aesthetic look. A few scratches on your structural pieces shouldn’t change anything.

Game Manual - R11 Certain non-VEX screws, nuts, and washers are allowed. Robots may use any commercially available #4, #6, #8, M3, M3.5, or M4 screw up to 2” (50.8mm) long (nominal), and any commercially available nut, washer, and/or spacer (up to 2” / 50.8mm long) to fit these screws.
The intent of the rule is to allow teams to purchase their own commodity hardware without introducing additional functionality not found in standard VEX equipment. It is up to inspectors to determine whether the non-VEX hardware has introduced additional functionality or not.

In the case of screws, nuts, and washers (and now spacers), they have a much broader range of acceptable options. Any #8 screw (for instance) with fitting nut picked up from a local hardware store would be acceptable.


Idk about you, but I’m pretty nuts😛

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