Rivnut Tool

[Forhire]

Testing is fun and you can learn a lot. Have you looked at the published ratings?
http://www.cardinalcomponents.com/as...properties.pdf

Like Clint mentioned fasteners under 1/4" will generally be measured in in/lbs rather than f/lbs.

Understand that the torque charts are a guide for a properly torqued fastener. These are within the working limits of the fastener. As you've discovered the shear point is quite a bit higher and material plays a big part.

I would think that if your seeing fastening system failures it is likely due to poorly designed joints and/or improper fastening system selection. Of course that's assuming proper installation.

[Bpk9p4]

Originally Posted by nirmatt_1690

If we need to put more than just a few, we use a pneumatic gun.

where did you get your pneumatic gun from and you have any idea on the cost. All the ones i can find are very expensive

[Thayer McCollum]

I did not know these were a thing. But let me tell you they have made my day and I fully intend to use them where I can now that I know about them. So thank you guys.

[ClockworkGold]

One of the ways we've used rivet nuts recently is to fasten our bumper frame to the chassis. On opposite sides, we have four 1/4-20 bolts spanning through the c-channel, 2x1x0.1 tube spacers, and into the threaded rivet nut.

Here is a top view
Here is a better angle

We also use the hand tool. We keep all of our rivet nuts in a special box with the gun.

[GeeTwo]

Originally Posted by Bpk9p4

My team has been using rivnuts for the past couple years and we love them.

Thanks for sharing! We have purchased a possibly identical tool and some 10-32 inserts from Hanson rivet. Before we use it, I'd like to ask a few questions.

Originally Posted by Bpk9p4

It works great but is hard on your hands after a while and prone to lots of error. Has anyone used an power tool rivnut gun?

What sort of error? How can we eliminate or at least reduce this error?

Originally Posted by topgun

Think about what the rivnut is doing, and how you can make your own tool.

Drill a close fit clearance hole for the size you are using in a piece of thicker steel. Put a bolt through the hole, screw the rivnut on the other side so it's tight. Place the rivnut in the mounting hole where you want it and use a powered drill to turn the bolt. Tightening the bolt will pull the rivnut bending portion tight to the mounting hole.

The tool we purchased pulls on the mandrel/bolt linearly, not through torque applied to the threads on the insert. Does pulling it this way result in a good set, or does the buckled part of the wall tend to twist under the torque?

We purchased steel inserts. Has anyone used the aluminum ones, and if so, what have you used them for, and how have they held up? Using a threaded aluminum fastener to secure a chassis or mount a manipulator sounds like a stretch.

Finally, the tool we have has several adjustments in order to fit the specific insert being used, particularly the mandrel extension distance. As we have only purchased a single size insert so far, this should not be an issue, but if you use multiple sizes, how successful have you been at getting students to do the adjustments whenever they change from one size to another?

Edit (addition):

Originally Posted by ClockworkGold

One of the ways we've used rivet nuts recently is to fasten our bumper frame to the chassis. On opposite sides, we have four 1/4-20 bolts spanning through the c-channel, 2x1x0.1 tube spacers, and into the threaded rivet nut.
[pics]
We also use the hand tool. We keep all of our rivet nuts in a special box with the gun.

Are the c-channel and tube spacers part of the bumper? How about the corner brackets?

We will also have a box just for the riveter, inserts, and the less-common sized drill bits needed for these inserts.

[Munchskull]

Always wanted to use Rivnuts and found this tool recently, thoughts?

[GeeTwo]

Originally Posted by Munchskull

Always wanted to use Rivnuts and found this tool recently, thoughts?

It's tough to tell from the picture, but it doesn't look nearly as sturdy as the one I linked above. The reviews on Amazon appear to support this - even the best review I read (****0) provided rather weak, qualified praise for the tool.

[JamesCH95]

We use rivnuts a bit, and use both aluminum and steel rivnuts. Aluminum ones are easy to install with a manual tool, and easier to replace than steel rivnuts. Steel ones appear to be a bit stronger than aluminum ones, obviously, but sizing the grip length properly keeps installation effort down.

Where it makes sense to, we use a clinch/PEM nut. They can be installed with an impact driver and a bolt, a machine vise, a press, or even a hammer if you're really hard-up (not recommended, but it works...). They are ~1/2 the cost of a rivnut and leave the clamping face of the part nice and flat. Their only real downsides are that they can't effectively be installed into some blind-hole applications such as the middle of a long tube, and require a tighter hole diameter tolerance than rivnuts.

My point is that if you're using rivnuts already it's only a small leap to get into PEM nuts which area cheaper, stronger, and offer different low-effort installation options without the need for any specialized tooling. We use both on our robots.

Here's a shot of our 2015 robot where you can see the use of a few steel rivnuts to anchor a transmission (the rivnut head fit nicely inside the hex relief on the transmission housing) and PEM nuts on the chassis brackets. Steel rivnuts worked well for the transmissions: strong enough, nice thread lead-in, plenty of back-side spacing to fit them, not too many to install, and installed into a plasma-cut and post-machined plate (loose-ish tolerances). The PEM nuts worked brilliantly on the brackets: short enough to fit together, installed two at a time in a machine vise, loads of strength.



In our 2016 our ransmissions were thru-bolted because that made more sense, axle bearings were retained with PEM nuts because of their low profile, the bellypan was anchored with aluminum rivnuts which were strong enough and super-easy to install, and the shoulder tube (that provided a majority of the chassis strength) was anchored to the chassis with 6x PEM-nut fasteners per side.

[Forhire]

Originally Posted by JamesCH95

Where it makes sense to, we use a clinch/PEM nut.

+1 for the PEM captive nuts. I use a lot of broach style and they are great. You can buy them from McMaster-Carr. https://www.mcmaster.com/#captive-nuts/=15l08yk

If you need large quantity I'd recommend S.W. Anderson http://www.swaco.com/ They can supply bulk bags for a fraction of McMaster.

For setting steel rivnuts I like the LEM tool. I have a set from #6 to 1/4. I haven't tried their spiral action speed header but it looks interesting. I've never set captive nuts with my LEM tool but it would likely work. http://www.lemtools.com/tools.php

[GeeTwo]

For the benefit of any who are considering whether to invest in trying rivnuts, here's my experience so far (first order received a few days ago).

I ordered the PNT-110 and a bag of SKL10-32-130 STEEL THIN-NUTs from Hanson Rivets. The web page for the inserts (rivnuts) specified a "grip range" of 0.02" to 0.13". As our primary use case is with 1/8" (0.0125") aluminum, and the secondary case is with thinner aluminum or steel, this seemed to be a minimal investment (less than $100) for a tool and a couple hundred inserts. While doing my Christmas shopping, I picked up a couple of 19/64" drill bits at Lowe's.

Saturday morning (yes, Christmas Eve, and my son's birthday), I drilled a hole in a piece of 1/8" aluminum bar and tried to set a rivnut in it. I tweaked the nose piece and used arm strength as well as hands, and even tried using the setter as a wrench on the threads, but I could not seem to get the insert to properly set. The insert seemed slightly swollen, but not set as a proper "rivet". For details, see the image, particularly the rivnut at the top, second from the right.

This morning (26 Dec), I had a bit of time to try a few things. My intention was to do a "pullout" test but this morning I decided to try a couple of other things first. I put an insert on the tool, and tried to set it in air. I am happy to report that this takes no more hand strength than a 3/8" rivet. The results are in the picture, third from right.

Then, I tried setting one of these rivnuts in 1/16" aluminum. I had a scrap of plywood edge channel handy, and the result is shown in the image at the far left.

I then did a few measurements of compressed and uncompressed inserts, and I am convinced that a '.130"' nut is only good for 1/8", or possibly 3/16" of material. I have ordered some rivnuts that support up to .225" thick, which should work quite well in 1/8" aluminum. 'll post some upgrades as I learn more.

[Foster]

I'd like to hear the results of the pullout test on the 1/8" bar where you don't think the nut really set well. It looks like it expanded enough to keep it from pulling out.

Thanks for giving up your holiday for Science!

[bowmanb]

I have extensive experience with rivnuts from one of my former lives as an instrumentation installer. They work great with proper installation and care, but I have always been reluctant to introduce them to our FRC team because of this one problem-

If you ever manage to break one loose in a blind hole it can be a real bear to get the screw out of the hole.

The odds of this happening increase as the odds of incorrect installation increases. When I finally broke down last season and introduced them (our chassis design last year made our bumpers hard to attach/detach without them) I trained a special crew to use them and I demonstrated the spin-out problem and how to avoid it. It requires a combination of correct installation of the proper size and avoiding over-torquing the fasteners (I find that often teenage boys don't know their own strength!).

[PVCMike]

We have used riv-nuts also called nut-certs (or nut-serts) on 1058 for years. Really helps with fast repairs in the pit!

Step one is get the right tool. We have one similar to this which works MUCH better than the ones that look like a pop-rivet gun: https://www.amazon.com/Astro-1442-Th.../dp/B003TODXQW

Step two is to make sure you have the correct size drill bit. These things are sensitive to hole size so we double check we are using the correct drill every time.

As others have mentioned installation and placement is critical. We almost always have mentor supervision/help when installing any riv-nuts. They are also prone to under and over torquing so we usually teach a few students how to do it properly and supervise closely, or have a mentor install if necessary (with student help of course.) It helps to do some testing on a scrap piece to make sure your tool adjustments are correct.

We have run into situations where they come loose due to install error or just unexpected load and have had success drilling them out, although it's not fun. I would not recommend using loctite on the hardware you're placing in them, and if you do, very sparingly.

I would be interested in a part number or link to a pneumatic tool for installing these. We use a pneumatic pop-rivet gun and it's awesome.

[Chris is me]

I vastly prefer riv-nuts to PEM nuts. PEM nuts have an awful tendency to fall out if mishandled, and because of that I don't really trust them. Once a riv-nut is properly installed, it has a much harder time coming lose. This is just my experience - both solutions are valid. But I don't think PEM nuts are almost ever preferable for me.

[Seth Mallory]

Originally Posted by Munchskull

Always wanted to use Rivnuts and found this tool recently, thoughts?

I do not recommended this tool. I have owned one of that construction and I hate it . All of that style at work, that includes the 4-6 that work buys a year, the round shaft comes loose over time and is frustrating to use. The tool from hansen is much better.