WCD Rivet Size

So this is our first year with wcd and we hit a little confusion on rivet sizes.

We ordered 3/16", but also ordered predrilled tubing and brackets from VEX which we realized last night is 5/32". We also picked up a couple of brackets off firstchoice to clear out the last of our points and see that those are 3/16"

Ordering new rivets is not a big deal, but are we better off with the smaller size or should we just get a couple students to drill out the other parts? I dropped of material to a machine shop this morning and told them I’ll get back to them today.

This is just the chassis at this point.

We use 3/16.

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We machine all of our own parts for our WCD instead of buying VersaTube. We also use 3/16 rivets to fasten these together. I would suggest you just drill out the tubing and gussets
to match this rivet size. It will also help you limit the number of unique rivet sizes on the robot, making repairs and design easier imo.

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I mean most people make their chassis for 3/16… so

We’ve used 5/32 for years without issue.

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A riveted joint needs a snug fit between the rivet and the hole the rivet goes through. Otherwise they can loosen up. 5/32 and 3/16 are so close that you’ll want to pick one or the other, but not both.

If you’re planning on using 3/16 holes from the brackets I would drill everything out to 3/16. If not, just make everything 5/32 and call it a day.

The bottom line is you should be able to use either without a problem. If you were asking before you ordered your rivets, I would have suggested buying 5/32 so you don’t have to do any post-machining on the VersaFrame. Since you already ordered the 3/16" rivets, there shouldn’t be a problem drilling out the holes you want to rivet. Make sure that you’re drilling a clean hole that’s perpendicular to the tube face and it should work fine.

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We use VersaChassis and VersaGussets and drill out all the holes we intend to rivet to 3/16”. We used 5/32” in 2015 and the start of 2016, but the 2016 game was not kind to our frame so we upgraded to 3/16” during that competition season and haven’t looked back.

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We use 3/16". We drill our chassis holes with a #11 drill on the router, everything by hand is done with a regular 3/16" drill bit.

Make sure you get the right length. Check the grip range

Going to chime in and say we use 3/16" was well. We still use the Vex gussets, but we drill and ream them out to #12 (0.189").

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3/16" here as well. We use that size primarily because if the rivets loosen up we just switch over the 10-32 bolts and don’t have to redrill anything.

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we made T-Gussets that have 3/16" holes but are using versachassis pre-drilled stock for our drivetrain (5/32") The difference in hole size is not that large, so we just widened the versachassis holes we were going to rivet to 3/16" and used 3/16" rivets as well.

(excuse the sharpie :grin:)

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Thanks for the replies everyone. Since we have a little bit of a mix between 5/32 and 3/16, we’ll go 3/16 and drill the others to match. Just wanted to make sure there wasn’t something I was missing

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Colored rivets are fun. Easy way to add color if students want to.

Another option is to powdercoat your frame in one go so the rivets are more uniform

In my experience the strength to color trade off is not worth it, but they do look nice.

I’m assuming you’re referring to the aluminum mandrel? I agree, but plenty of places on FRC robots where they’re appropriate.

No, tensile and shear strength are very different when comparing colored and non colored 3/16 rivets with both having aluminum mandrels. The colored ones do have their place I agree with you but its just something to be mindful of!

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Huh wow I’ll be honest I never noticed on MCM they are rated differently. Good catch!

We had a real problem one year with them shearing pretty frequently, I checked the ratings and sure enough they are way different. What would happen is over time they would become really “loose” and then shortly after they would shear. Now if I want colored rivets I powder coat my own.

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