New team help (on frame design guidance)

[team3329]

We are basically a rookie team (we started in January year in FRC with a 4 man team, and we now have over 20.). does anyone have advice for basic frame and layout designs? should we use the basic frame that we are given each year to base the competition bot off of? and what materials are good to use for the frame and platforms? THANKS!

[lbarger]

Originally Posted by team3329

We are basically a rookie team (we started in January year in FRC with a 4 man team, and we now have over 20.). does anyone have advice for basic frame and layout designs? should we use the basic frame that we are given each year to base the competition bot off of? and what materials are good to use for the frame and platforms? THANKS!

You are asking for a lot of information. There are literally volumes of content here on CD as well as other sites such as wpi, andymark, canadafirst.

I've put together a couple of presentations covering mobility and materials for a workshop held in NC back in October. I included speaking notes in the PowerPoint files to explain what each slide was about. These presentations as well as many other have been posted on the NC FIRST web site...

http://www.ncfirstrobotics.org/index...-2010-workshop. This links takes to the schedule for the event. We captured each canned presentation and made the title a link. Some sections were more demos or open discussions so presentations were not available.

If you have specific questions (wide vs. narrow, 4 vs. 6wd, etc) that may help us give you more concise responses.

[artdutra04]

Search through the CD-Media photo galleries and white papers. There are easily hundreds of photos and documents about chassis and drive train design. Otherwise, asking what's the "best" way to design a drive train and chassis will get a thousand different answers.

Also, a lot of chassis and drive train decisions are made based upon the manufacturing capability of a team. Without this information, it's impossible to make recommendations.

[Chris is me]

If it's a month before Kickoff and you're not sure what to do, without knowing what engineers and resources you have, I would say use the kit frame, or possibly the IFI Kitbot. The former has been changing every year but is always a robust solution to the game challenge, and the latter (much like the former) is probably one of the best designed drivetrains in all of FIRST. The KoP is good stuff.

[Al Skierkiewicz]

As this is your first year developing a robot, you might be best to use the kitbot chassis to establish a driving base. One of the biggest failings of any team is the failure to get drivers practiced using the robot that will be in competition. I have often advised rookie teams to have a driving base by the end of week two and pick a drive team so they can get a handle on how the base drives and responds to commands. The best base in the world will not make a team win if they still can't drive it in competition. Until the game is announced, you do not know what other functionality you will need to build and test. When putting together the kit don't forget that you musts mount bumpers on it when you drive it. Get the height and wheel size correct so that the bumpers will not be an issue.

[team3329]

Thanks!
We did very well at Breakaway this year, and we used the KoP base and frame. We probably had one of the simplest robots (albiet one of the fastest), and we used the dual chain drive system provided in the KoP. It worked okay, but we want to expand this year and go beyond just what we are given in the KoP. We want to add more capability to our robot while maintaining the mobility that we enjoyed so much at competition. Any ideas on strong-but-light materials for such a purpose?

[Al Skierkiewicz]

To build on what you have already accomplished, you might want to look into shifting Andy Mark transmissions to give you optimized speed and/or pushing power. However, depending on the game you may not need one or the other. Many teams use aluminum box tube for chassis construction. Welding is the preferred method of assembly. Others use rectangular aluminum box tube for axle and drive train mounting while connecting the two tubes with cross bracing of other materials like round tube or structural extrusions.
Remember that the game should dictate function. If the game calls for a robot to precisely pick and place objects, a running speed of 20 feet per second is likely to prove frustrating to drive. A tank style drive is also not indicated if the game is going to require repeated high speed turns with small turning radii.

[ajlapp]

There are off-the-shelf solutions available as well.

These designs are open-source, so feel free to adapt, change, modify or learn from them as needed.

When in doubt, first year teams should always use the KoP chassis system.

[Andrew Schreiber]

Originally Posted by ajlapp

There are
When in doubt, first year teams should always use the KoP chassis system.

Heck, 10th year teams can listen to that advice too.

[JamesCH95]

Originally Posted by Andrew Schreiber

Heck, 10th year teams can listen to that advice too.

There's a lot to be said for just having it be done! If you want to get a little fancy weld the kit-frame together, you'll save a few pounds in fasteners and brackets.