pic: 4587-Sheet Metal Chassis V.2

[Cash4587]

Originally Posted by AllenGregoryIV

Cooper this is looking really good, do you have pictures of the underside? Looks like the motors aren't directly driving the omni wheels shaft anymore.

One thing we did this year was make it so the front and back rails of the chassis were easily replaced. It worked out very well for maintenance.

The motors still drive the Omni shafts directly. I just have removed the "Gearbox" that would have previously been inside the frame and moved the gears to inside the wheel rail. I had to add another gear to make room for the long cim motor shafts to still keep the wheel rails small-er. I kept them about a 1/2" smaller or so by adding another gear.

As for removing the back rails of the chassis, It would be convenient but I wanted to make the belly pan one piece. I plan to not put a whole lot down there to make it hard to work on. Maybe like a flip up electronics pan that hangs the electronics in the frame. Idk. Majority of the parts for the actual drive train have to be accessed by the bottom anyway, the modules will drop out from the bottom, and the motors have to be bolted on through the bottom too as well as all the gears and other parts.

Here is a picture of the underneath with the belly pan transparent:
http://prntscr.com/406565

Nice! Looks like a solid design, and like you got all the tricky bits right.

I'd put some material back in the front and back of the frame. Those parts take a beating... You can drop some of the material on the top of the frame, and on the rails holding the wheels. The frame itself will be strong enough, and the holes make it easy to inspect your robot for wear. Point impact loads from other robots and field elements should be your biggest loads. You can take the inner frame rails down to 060 as well. Reinforce the bearing holes when you do that.

Consider lightening the belly pan, and adding PEM nuts in for your electronics. Those small touches take a design to the next level.

I didn't know exactly how much to take out from the back and front but it's good to know that more is needed back in. I do however plan to take material out from the rails. A lot of that is doubled up so it will be .180" instead of just .090" It will see some heavy patterns in the near future. I probably will end up making the belly pan either an X pattern Like 254 or lots of big round holes. Last season my team ran a belly pan made of .090" with the 254 style pattern with holes for every electronic hole there and ready to go for bolts. I put in the correct tap drill size in the CAD and sent the dxf off to the laser and they had enough tolerance to where I could just tap the hole directly from the sponsor with out having to do any drilling. After we tapped the holes we then bolted down all the electronics with plastic bolts and used a pair of dikes to cut off the extra bolt that would stick out bellow the belly pan. I really liked this method and I plan to do it again, it was simple and made doing electronics TONS easier as far as mounting them. Wiring is always a different story..