Chassis weight

[pmangels17]

Originally Posted by Chris is me

I think this is a really bad idea. Those hex shafts are designed to be used as spacers, not as drive axles. That part could easily fail when you need it the most.

Spend your weight where it matters. The drivetrain matters.

I think I misspoke, or you misunderstood me. http://www.andymark.com/product-p/am-superoptions.htm
The black plates seen in the image on this page serve as a spacer. We replaced those with this:
http://www.andymark.com/product-p/am-2241.htm
We didn't skimp on anything like a shaft. I misspoke when I called it shaft material. We did use it as a spacer. By using it, we saved a lot of weight.
When I referred to side plates, I didn't mean the main plates, I mean the other four sides, which I replaced with spacers. I apologize for saying it wrong.

[Chris is me]

Oh, I'm sorry, I assumed you were using the cross hex to drive a shaft. Only reason I jumped on it is because I've actually seen teams try to do that on a robot before.

[LightSpeedIII]

Originally Posted by nathan_hui

Did you take into account the 5 lbs or so of bolts, nuts, and washers that usually come together with a chassis? As well as each motor's actual weight?

If I'm not mistaken (and I very well may be), the frame will be welded together, leaving the only bolts, nuts and washers on the frame being used to mount the gearboxes and modules. That weight should include motors, but in the event that it doesn't, adding the weight of 4 CIMs to the 25lb approximation would put it at just a little over 36 pounds.

[pmangels17]

Oh, no. I just shuddered at the thought. But we will be machining some custom shafts for direct drive, instead of paying for the AM ones. We have two great students (I'd like to think that I'm one of them) that are good at the lathe. I am more the mill guy, and he is more the lathe guy, as we call each other. We also have a tool and dye machinist who works with us as a mentor, and he can practically make anything.