Prevent drive train axles from sanding out aluminum holes?

you can remove the threads if you open up the motor, but vex doesn’t sell any replacement threads. Someone, I believe it was @technik3k, found a very close replacement part online that is almost identical to the threads, just using 6-32 screws. Here is technik’s post about this. I don’t think they are technically legal, but you aren’t gaining any unfair advantage by doing so, and its not like inspectors are going to make you show them each of your motor threads, so I mean…

4 Likes

“It’s only illegal if you get caught…”

3 Likes

Yes but if you juse use nylocks the motor may be mounted at an angle because the screw has room in the metal holes. Bearing flats kind of “snap” into place with the little ridges on them, so the bearing flat is taking the job of the bronze inlets.

VEX ruled it legal to replace the metal threads with their standoffs. Also if you do have broken motors you could take the threads out of the motors and put them into the working motors.

You mean “Lets do things that could potentially get us caught and banned from the competition!”
Or I can rephrase it to “Is doing said illegal action worth the potential of getting banned from the competition?”

I was never suggesting using nylocks on the motor? And yes, I mentioned that the both the bearing flats and the motors fit into the holes in the c-channel.

My apologies I guess I misunderstood your post. The entire purpose of having nylocks with the motors is to have the motor stay on the metal tight and would never loosen for a longer period of time. By not tightening the motor as much as possible yoy are basically begging for the screws on the motor to get loose.

Personally, I’ve never felt the need to put nylocks on anything where a keps would do just fine. When it comes to motors, especially with the v5 motors, I haven’t found that the screws come loose that much at all. But whenever I am building something, I make sure that the screws are still accessible just in case. And yes, motors have rarely come loose time to time but I don’t think its worth the added weight and hassle because putting nylocks on your motors is going to take up more space as well.

3 Likes

I want to say that you don’t NEED the nylocks per se - it is just a remedy to a frequently occurring problem. For this, you’d need a whopping total of 16 nylocks. To me, the weight of 16 nylocks is negligible as that weight would be spread rather evenly throughout the robot. If 16 nylocks makes your robot noticeably slower then you have a serious problem. Otherwise, unless you’re building an ultra compact robot, nylocks are a good preventative measure to not having a motor come loose.

Personally, I dislike keps nuts. They are a hassle to work with because they come loose frequently. I found that even when I over tighten them, they would eventually come loose. This was not the case for nylocks however. If you’re willing to keep retightening the screws after extensive robot use, then go ahead and do that. In fact, the main reason I came up with this solution was because I got tired of retightening those screws. Just my two cents on the topic.

2 Likes

Tbh I dont think the judges would be able to disqualify you for that. Like are we supposed to buy a new motor? Two threads broke in the last week! (Also vex doesn’t sell replacements or offer any sort of repairs)

1 Like

I thought about having this mentality a lot. “Ah its just one extra nut here or there”. But it turns out, if you have that attitude towards the entire robot, the weight adds up. Maybe the difference for me is that I’ve never seemed to have such a problem with the keps nut. Either way, I guess it comes down to preference.

2 Likes

I completely agree with you. This mindset would be especially helpful for v4 given the limitations of those motors. Weight adds traction, however you need to find the right balance between weight and speed. Particularly for your team (previous World Champs), I admire the measures you guys went through to decrease the weight of your robot.

1 Like

Thank you! I couldn’t agree more in terms of finding the right balance between weight and speed. You definitely don’t want a robot that’s prone to tipping and falling apart because it is light and weak but you also don’t want a 35 lbs robot.

1 Like

The weight of thin nylocks are completely identical to keps nuts, so there is absolutely no reason to decide keps nuts over nylocks simply because of weight. :wink:

5 Likes

Oh I had forgotten about these. Is there and major draw backs to using this over a regular nylock?

I mainly use keps nuts for temporary placement of something or when I’m testing something out because they can be hand tightened. Then I go back and swap out a keps nut for a nylock once I’m certain that it will be the permanent location of said nylock. (unless it’s for a screw joint or something of that nature).

1 Like

In my opinion the bigger argument is how much easier keps nuts are to work with. For a simple prototype, you can often tighten by hand, and you can get more than tight enough to stay together permanently using a decent screwdriver and any wrench.

FYI, there’s nothing wrong with using keps nuts permanently, so long as they’re adequately tightened.

1 Like

I don’t feel comfortable using keps nuts on important screws, so I tend to avoid them. but they are great for quick prototyping.

4 Likes

Same, I like to use unlocks on all important joints. If it’s some nonessential mechanism, then I tend to use keps nuts instead

2 Likes

I think the extra effort to screw on a locknut is worth not having to worry about that screw coming out.
what vex needs are lock standoffs that are basically standoffs with little nylock parts on both ends.

5 Likes

You could also use Delrin Bearings from Vex’s website.