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Unread 27-07-2016, 10:31
sanddrag sanddrag is offline
On to my 16th year in FRC
FRC #0696 (Circuit Breakers)
Team Role: Teacher
 
Join Date: Jul 2002
Rookie Year: 2002
Location: Glendale, CA
Posts: 8,507
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Re: Who makes their own wheels?

At 696, we made custom wheels for years. When we easily bent our 2005 wheels (1st link) on multiple occasions, which really surprised me since the spokes were 1/4" thick. That inspired me to design a better wheel. That instance is what first caused me to learn how to do stress analysis and FEA, and in 2007, I assisted students with the design of a very lightweight (4 oz) 5 inch diameter CNC machined aluminum wheel (2nd link), that was incredibly strong. They had a design already, but with just a couple tweaks and a couple runs through FEA, as a mentor I was able to help them see the potential failure points, make the wheel at least twice as strong, and reduce the weight. This was real engineering, and not that picking parts out of a catalog isn't, but it's a different type of engineering. In 2014, we did some 4" wheels that really had some nice style to them, in addition to being lightweight. We've also done custom wheels in other years, like our 10" dish wheels in 2010, and 3.5" machined wheels in 2013, and custom hubs for mountain board wheels in 2016.

To me, a lot of the real "let's sit down and design and analyze and calculate this" type of engineering by and large has been on the decline in FIRST Robotics, and the "Let's open the catalog and find something that works" or "let's watch what other people do and do that too" is heavily on the rise. I don't want derail this thread this into a COTS vs custom debate, but while we have made our wheels in the past, I don't know if we always would in the future, and I kind of miss it. You see even teams like 254 using Colson wheels

For students, there is really something magical about designing and making your own wheel, and it's a lot of fun. But today, the competition is really more about time. The less time you spend designing and making things you can buy, the more time you can spend on the other things. And in some sense, I kind of hate that. I have a lab full of CNC machines, and we can manufacture anything. We bought VEX ball-shifters for our 2016 robot, and I have a stock of VersaFrame gussets and Versaplanetaries for our 2017 robot. Why? While we can manufacture literally just about anything a FIRST robot would ever need in our lab, we can't manufacture time. By buying COTS parts, we are buying time, and while I do like that, at the same time I don't.

Anyhow, back to the wheels.

In 2009, there was a team 13something (1388?) from an area near San Luis Obispo, CA that had a great 13lb flywheel gyro mechanism that allowed their robot to "lurch" forward when they tilted it, to push their opponents and pull the trailer. It was a great way to get more "thrust" in a game where you couldn't just add more traction, and it worked pretty well actually.
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Teacher/Engineer/Machinist - Team 696 Circuit Breakers, 2011 - Present
Mentor/Engineer/Machinist, Team 968 RAWC, 2007-2010
Technical Mentor, Team 696 Circuit Breakers, 2005-2007
Student Mechanical Leader and Driver, Team 696 Circuit Breakers, 2002-2004
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