pic: 1058 PVC Pirates 2016 Robot: Low Expectations

[maxnz]

When we were building our robot's intake arm, an experienced mentor from 2177 and (I think) 2526 recommended that we use rivet nuts. He said that he usually recommends them to teams that are starting to become more competitive and advanced, where a chassis of c-channel, nuts and bolts is a little too easy.

[PVCMike]

I've been on 1058 for ever and have also used riv-nuts at work a lot. They're sometimes called nut-serts as well. They are super useful but there are some precautions to take. Similar to rivets they have an intended grip range so keep an eye on that. Additionally they are fairly sensitive to hole size so make sure you're using the correct drill. Lastly NO LOCTITE! The major risk with riv-nuts (which is almost completely eliminated with proper installation) is that if they come loose they can turn and that makes removal of the bolt a real challenge. Also you now have a useless riv-nut you need to drill out and replace. As Brendan said though they're really useful, eliminate a lot of wrenching, and make for nice compact assemblies. We really like them!

[maxnz]

Originally Posted by PVCMike

Additionally they are fairly sensitive to hole size so make sure you're using the correct drill.

One of our types of 1/4-20 rivet nuts require a Q size drill bit. We invested in a letter drill bit set after trying to figure out if any of our standard drill bits would work. I can say from experience that they don't like to work with a hole that is even a 16th of an inch off.

[Chris is me]

Riv-nuts are fantastic and every team should use them wherever they can. They make almost any situation into one where you can blindly install a bolt with tool access on just one side. No more losing / dropping nuts or anything like that.

You HAVE to install them correctly or they will spin in place uselessly (you can fix this usually by just tightening it more). But if you do they are very strong - 2791 would actually lift their entire robot from 4 1/4-20 eye bolts screwed into rivet nuts!

I have never run into any issues with Loctite and these, just don't use too much Loctite (a TINY amount of blue only) and you're OK.

If you want to cheat, you can actually use rivet nuts with a long enough grip range in a manner similar to rivets and fasten two plates together by installing a riv nut through both of them. Then you can bolt whatever to the two riv-nut assembly.

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Oh, and fantastic robot 1058! It was awesome competing with you guys at Rhode Island; you were clearly the best ball cycler at the event, and picking you nearly guaranteed a capture.