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Unread 05-24-2014, 11:28 AM
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Billfred Billfred is offline
...and you can't! teach! that!
FRC #5402 (Iron Kings); no team (AndyMark)
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Re: New season, New tools

Quote:
Originally Posted by daliberator View Post
That's kind of what I what I was thinking about the welder. I feel silly saying this, but I have literally no experience with pop rivets at all, although I do know that they can be very useful. Can you recommend some learning resources and/or some specific gear to get started?
I don't know that there's been a definitive tutorial in rivet usage, but I can share a few examples from my past:

4901 (2014) Everything you see on the wings and the shooter arm is just 1" square tubing from our local sponsor Metal Supermarkets (#plug). Some of the gussets holding it together are VexPro Versaframe gussets, some of it is their pattern cut and drilled in-house on a bandsaw and drill press. These were 5/32" rivets, since that's what VexPro uses and we didn't have any other standardized size before.

VexPro Build Blitz (2014) Just for a taste of what's available strictly off the shelf when it comes to framing and gussets. We used their hole pattern this year and just drilled it into our metal. We called it Worseaframe.

1618 (2009) Crazy simple design, with each piece of angle just riveted together. Zero issues (with that anyway) all season. I'm guessing those were 3/16" from the photos.

2815 (2012) This time, it was square tubing and some angle aluminum to hold it together. Despite a couple of faceplants (it was rather butt-heavy), I don't think we ever had to tap the box of black rivets I bought as a fail-safe (all the OE rivets were standard ones painted black). These were all 1/8" rivets far as I remember.

2815/1398 (2010) This is a good up-close look at the way-too-idle Stephen Kowski's work in action. You'll note that the rivets are holding the entire chassis together (think those were 3/16"), and the kicker foot, and the kicker to the chassis...

2815 (2009) There weren't as many rivets on this one compared to others, but the upper and lower halves of the ball conveyor were joined by that angled flange down towards the bottom. Each side just had a bunch of rivets sunk into it, and it's probably still together in 3976's shop. (We used shoulder bolts into the bearing holes to keep the two sides together, some threaded inserts too. The idea was to keep it so we could get in there for maintenance if needed.) The rivets we used there were 1/8".

1501 (...just pick one!)

For practical hands-on testing at your facility? I'd say build something like an arm frame (use PVC pipe or a 2x4 for the arm and a bolt for the axle, just keep the unsupported length relatively short), strap it to a furniture dolly, and run it through some tests to see how they hold up. It isn't a substitute for full-on engineering analysis, but for the cost (around $50-60 if you had no extra aluminum lying around and with leftover rivets and riveter) it's pretty cheap to dive in.

Your local hardware store will have most of the stuff you'd need: a riveter, a couple boxes of rivets (aluminum is fine), a drill bit to match those rivets (the rivet box will tell you the drill size--5/32" is a #20), and some square and angle aluminum (1/16" wall is probably what's there, and that's fine).

I will note that McMaster-Carr's prices are significantly cheaper for rivets than any hardware store around here. Buy in bulk or with other robot stuff, and you'll save significant money over the course of a season. Riveters themselves are about a wash; at $20 or so for a manual one, I view them as a consumable since they usually last about .75-1.25 seasons. If you've got shop air or a compressor for tools, Harbor Freight sells an eminently decent pneumatic riveter too.

tl;dr Rivets are simple enough that a guy with a business degree can't even screw them up.
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William "Billfred" Leverette - Gamecock/Jessica Boucher victim/Marketing & Sales Specialist at AndyMark

2004-2006: FRC 1293 (D5 Robotics) - Student, Mentor, Coach
2007-2009: FRC 1618 (Capital Robotics) - Mentor, Coach
2009-2013: FRC 2815 (Los Pollos Locos) - Mentor, Coach - Palmetto '09, Peachtree '11, Palmetto '11, Palmetto '12
2010: FRC 1398 (Keenan Robo-Raiders) - Mentor - Palmetto '10
2014-2016: FRC 4901 (Garnet Squadron) - Co-Founder and Head Bot Coach - Orlando '14, SCRIW '16
2017-: FRC 5402 (Iron Kings) - Mentor

93 events (more than will fit in a ChiefDelphi signature), 13 seasons, over 60,000 miles, and still on a mission from Bob.

Rule #1: Do not die. Rule #2: Be respectful. Rule #3: Be safe. Rule #4: Follow the handbook.
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