pic: Team 2791 Modular Chassis

[Sh1ine]

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[AdamHeard]

I would add standoffs to the bottom and/or make the wheel axles rigid parts of the frame by being a standoff. Currently, they appear to only be rigidly attached on top. You should also probably lighten those rails a bit with some pocketing, there is certainly a lot of meat there.

[rulesall2]

This is just a prototype, just to clear up some questions.

[Racer26]

This looks very similar to a "west-coast" style 6wd only with 2 extra wheels.

1075 ran a similarly constructed unit in 2008 offseason at Brunswick Eruption 7, those look like AM Plaction wheels. Are the 2 middle wheels dropped relative to the outside ones?

[Akash Rastogi]

Love it.

One suggestion: In our extensive experience with 1/4" plates, it can be overkill and overweight. Have you considered switching to 3/16 or 1/8"? It would allow you to save some machine time with pocketing the 1/4" plates.

Nice job. I really look forward to seeing what comes out from 2791.

[rulesall2]

Originally Posted by 1075guy

Are the 2 middle wheels dropped relative to the outside ones?

Yes, the middle wheels would be dropped 1/8'' from the outside ones.

[Sh1ine]

Yeah I have considered 3/16" Al. Not 1/8", do you think that would be strong enough?

[AdamHeard]

Originally Posted by Sh1ine

Yeah I have considered 3/16" Al. Not 1/8", do you think that would be strong enough?

If you have enough standoffs and in the right plates, you're effectively making a very large I-Beam. If you look at a piece of 4"x4" by 1/8" wall thickness square tubing, the walls seem "thin", but the overall piece is very strong because of it's shape.

You want your designs to be strong by the nature of their shape, rather than just adding more material.

[artdutra04]

Originally Posted by Sh1ine

Yeah I have considered 3/16" Al. Not 1/8", do you think that would be strong enough?

If you have access to sheet metal working equipment, you can cold roll flanges onto 5052 aluminum (don't try this on 6061 unless you have a large bend radius) sheets as thin as .090 to .125 for a base chassis. Team 228 used .125 5052-H32 aluminum for our robot chassis in 2007, 2009 (and soon to be 2010 ) to much success. Here's a photo of our 2009 practice robot frame:

I like it! Looks like a very solid start. Some things to keep in mind:

-Chain tension. Are you tensioning the chain, or have you run your numbers on sprocket distance?
-Support. How much support do the two plates have between them?
-Live or dead axles?
-How quickly can you repair it if or when it breaks?

Looks like a solid start!

[Sh1ine]

OK, talking about standoffs I forgot to mention that the axles are going to be standoffs. My content center is not loaded on Inventor but I am going to use 1/2" through bolts for axles, then utilize spacers to keep the wheels aligned.

[Chris is me]

Not a bad prototype. Didn't know I had such talented teammates.

Would this be easy to throw AM or laser cut floating tensioners on?

[Sh1ine]

Thats the plan.