pic: Coaxial Swerve drive, lightened.

[DB_UPS]

If you want to make some thing works. You can do. It may not look pretty, but it would work.

Just in case people are wondering why we would go with 1/4" plate rather than sheet metal, here are our reason: it's light enough, we get mass amounts of it for free, our CNC sponsor prefers doing machining on this plate, and it's quite strong for its use.

[Greg Needel]

Originally Posted by 114ManualLabor

Inventor 11's stress analysis tells me that it can take about 900 pounds of sideload as a whole, which just might be enough for a FIRST bot.

This quote scares me a bit. I just want to warn you and everyone else about integrated FEA in software, especially inventor. FEA is good when you have an idea about how strong something is and you just want a verification. ie. you have already calculated an approximation using a number of other methods, or you are familiar with your mechanical properties of the materials and their metal working abilities. IT is NOT OK just to click a couple buttons and assume that the number that it gives you is what you are going to get. First of all nothing that is build comes out exactly like the cad model, no matter how good your machining abilities are. Next there are a number of mistakes that can exist in a cad model from small keystroke errors or incorrect constraints.

I am not trying to come down on you i am just trying to warn people that if you blindly trust a number that the computer gives you without understanding what it is calculating you have the possibility of large errors, which could be catastrophic in your machine.

[Nuttyman54]

i'm not familiar w/ the stress analysis tools in Inventor, but you might want to check that it's not just telling you that if you apply uniform pressure along all lateral surfaces you can survive up to 900 lbs before deforming. Looking at weak points, i'd be VERRRY surprised if it could take 900 lbs at the joint.

EDIT: Thought of another thing: are you treating this as one solid object? It occurred to me that the bolts might sheer off before you reach that 900 lb limit....

I believe I did something wrong in the stress test... not sure what yet... I'll let y'all know when I find out where I messed up...