Re: Ribbit Rivet...
 

Glad you guys are having good luck with the rivets. They have been a very successful method for our team since 2002. One more tip. When drilling for the 1/8" rivets we use double end short drill bits that are typically used by sheet metal duct fabricator. They drill aluminum well and when the bit dulls just flip it. Once again we have never had a riveted joint fail. About 4 joints over all those years loosened a little.

Re: Ribbit Rivet...
 

Billfred, we also had similar issues with the Harbor Freight riveter - it wouldn't let go of the mandrel after popping the rivet.

We fixed it with a liberal application of grease to the gripping jaws. After removing the outer tube, we also unscrewed the inner tube. Some grease on the jaw outsides and they were reinserted, along with the spring, and tightened. Then we added a healthy dollop of grease to the inside of outer tube (and got it all the way in to the bottom, maybe 1/2" deep, around the screw in nose-piece) and screwed it all together - now it works like a charm.

You definitely get what you pay for.

Don

Re: Ribbit Rivet...
 

I add a little twist to that old phrase:

You usually don't get what you don't pay for.


Anyways, thanks for the rivet gun lube instructions, that is something I never though of and sounds very helpful!

We've had lots of small rivets fail, but we use them where we shouldn't, and we also use them as sort of a safety valve....the little rivets break off instead of letting the mechanism get bent up.

Re: Ribbit Rivet...
 

Lubrication could well be an issue with the HF riveters, now that I think about it--over the multiple times I disassembled it, it appeared that there was only just enough lubrication to get your hands messy.

Of course, to fix that would involve getting the kids away from the Big Daddy Riveter. That might be a task. ;)

Re: Ribbit Rivet...
 

I challenge any team to build their robot with 95%+ rivets :D
Team 1501's Scorpion had 1900+ rivets :ahh:
In the three years that we have been around we have probably used almost 5000 rivets.
Beat that, if you can :D

Re: Ribbit Rivet...
 

Ha! We've used over 10,000 rivets....:D

...all in the very same hole.:ahh: Darn it, Eric, learn how to set those rivets already!

(Er, just kidding. We're up to maybe 50 or 60):p


Don

Re: Ribbit Rivet...
 

We're probably near 100 rivets between the wheel tread and the frame, and I am enjoying it. Our superstructure is still in a state of flux because of other things, but someone will have to make a good case for us not to use 'em.

Re: Ribbit Rivet...
 

Who uses rivets instead of bolts on pretty much everything? we've been using 1/8" rivets for minor construction things but not a whole lot. Our we underestimating the rivet?

Re: Ribbit Rivet...
 

Andy,

You are grossly underestimating the rivet. We use them for almost every mechanical joint. The only structural place we don't use them is on the end of our wheel shafts to retain the wheel as the shaft is not very conducive to taking rivets. We use bolts to temporarily hold things together until we rivet them.

-Paul

Re: Ribbit Rivet...
 

We've been using a lot of rivets this year, and designing the robot to be able to use them in many places. The ball manipulator stuff is mostly thinwall aluminum tubing held together with sheet aluminum brackets riveted on, the chassis is fiberglass channel and sheet aluminum riveted together. The framework that hold the ball manipulator stuff is aluminum angle, which we are bolting together, but we might replace some of the bolts with rivets. We are again using a modular design, so there are 4 easy to reach bolts holding the ball manipulating assembly to the chassis, for quick full access to the drivetrain/electronics for repair.

Re: Ribbit Rivet...
 

A 1/8 rivet will not fit into a 1/8" hole. You need to use a #30 drill bit. You also need to use Clecos and Cleco pliers (to install and remove Clecos)

Re: Ribbit Rivet...
 

Well, now that ship has come and gone, I can more fully take stock of how it turned out.

We wound up riveting our entire frame using 1/4" rivets; the only places we took them out were places where we wanted to mount other things with bolts. (I'm starting to believe Paul and his speed claims after making those changes.)

The result held itself together well through weeks of inexperienced students working around them and some bumperless bumping around the hallways of Columbia High. We didn't have a chance to see how the frame holds up to competition-grade whacks, but I remain pretty optimistic. I'll wait on the Chesapeake postmortem before declaring it a success, though.

The best picture I have of our handiwork is seen at http://www.flickr.com/photos/billfred/2283099106/ that photo is from about a week before ship day.

Re: Ribbit Rivet...
 

I removed the semicolon that snuck into your link

Seems that rivets work better when you use several of them, smaller sized, and on joints that are designed for them. In other words, you kind of have to design the robot around the assembly method...and the kit frame is designed to bolt together. It should hold up ok, but you might want to look at some other riveted robots for ideas for next year.

Re: Ribbit Rivet...
 

We riveted most of the Kitbot connections, and left bolts in some others. I don't have a good photo - wait until later this weekend, after NJ - but IIRC we riveted all the places where there were 2 'bolts' holding something, and bolted the 'single bolt' places, with the notable exception of all the ones where they might stick out into the bumper space.

We were really unhappy with the Harbor Freight riveter, but didn't have the funds to get a better one. We did have to keep it leberally greased just to function - the problem was that it would not release the manderl after the 'pop'. One of these days, I'll try to figure out why that is so.

I like the idea of a pneumatic riveter. Almost as cool as a hand-operated hydraulic hole punch (which I first saw at Palmetto)

Don

Re: Ribbit Rivet...
 

Rivets are quite godly indeed...

we use rivets wherever possible. Usually, we use the 3/16 variety for mid-high stress and then 1/8 for low stress applications. It saves quite a bit of weight compared to bolts.

We also got a very nice pneumatic riveter this year, which handles rivets VERY well, much better and faster than our old manual ones.

Personally, I find using rivets more convenient. Even if you need to remove them, it's usually not hard (just get a slightly undersize drill bit and pop it out). However, when the end of the rivet shaft dosent pop out right, then it's tricky to drill out without damaging the hole/piece.

Overall, though, I love rivets, and they're very likely why we're able to stay at weight. =D