6502’s second take at an octocanum pod.
More images and description of design here: http://imgur.com/a/9M3dD
A360 Link For Viewing In 3D: Fusion
6502’s second take at an octocanum pod.
If you don’t mind me asking, what are the changes between this module and the V1?
Your outboard bearing plate seems to only have 1 screw attaching it to the other main plate. You’ll want at least 2, preferably 3. The bolt hole also seems to have suspiciously small wall thickness on the bottom.
What ratio are you running on the mecanum wheel?
The differences between this design and the V1 are the Cim faceplates, adding standoffs, and general rigidity improvements. For the standoffs, two or even three more can easily be added using the existing holes, I will just need to expand them outwards so that they don’t interfere with the gears. The thin wall thickness on the bottom standoff is because the screw holding the standoff is countersunk .1" into the .25" plate. All the gear ratios are in the imgur album, but the main idler gear is 72t and the mecanum gear is a 54t.
54:12 on a 4" mecanum is 21fps free speed. IIRC the response of a mecanum drives doing holonomic moves (like sideways translation) starts getting wonky above ~17fps. You maybe want to test the max usable speed of a mecanum before making this drivetrain.
IMO your lightening pattern is very aggressive. These pods will be taking large shock loads in almost every direction, and any bending or mis-alignment will wreak havoc on the gear meshes. It’s one thing to aggressively lighten a WCD gearbox that barely sees any outside force, but these modules will take a beating on a regular basis. Especially in the drivetrain (i.e. the most important system on the robot), you really should take the extra few pounds to make sure it’s robust and sturdy.
I’ll second more screws on the outside plate (~4 if you keep that size), and I’d also recommend using bigger screws if possible. The inside plates could also have more/bigger screws to help increase rigidity. You really don’t want this thing racking; it will not be fun.
I still don’t see a mounting place for the pneumatic actuator. I know the module is supposed to pivot around the Colson, but you need a place for the piston* to attach. That also needs to be attached strongly, because all of the force holding the robot on the mecanums is going through that attachment point.
*Yes I mean piston, not cylinder. IACNAP campaign is not welcome here 
Some quick takes:
That outer plate of the module is going to need more than one screw to stay on with any degree of good alignment or rigidity. It’s doing very little for you now. There is way too little material around the bottom of that screw, and the screw looks like it could be as small as a #4-40 flathead? Maybe they’re #8-32s, but even so you need more than one of them. This is a key structural part of your module, not a decorative plate.
Your CIMs use 12T pinions, but use a giant clearance hole to mount. The CIMs have a raised .750" boss in the middle that is perfect for piloting the motor and ensuring a good gear mesh, and with a 12T pinion there is no reason not to use it. You’re just making your gear alignment worse for no real benefit.
Finally, the lightening pattern doesn’t make a lot of sense, and it is generally too aggressive. It seems like you designed the module around the lightening, rather than designing the module and then lightening later. Drive modules like this deal with a lot of forces directly, more so than a normal gearbox, and you need to be a lot more careful with the structure of them.
Do you have a lot of experience with custom gearboxes? I am not sure an octocanum module is where I would invest my design efforts if I didn’t have a really firm grasp of other FRC engineering principles - a lot of subtle details to get right, on top of the big things like structure and rigidity and alignment.
Another thing to add on to what others have said. Have you added any distance between the gears in addition to the exact center to center (usually about .003")? You need tolerance and it doesn’t look like you have added any.
Edit: I also noticed you have 3 bearings on a couple of your shafts. That also over-constrains them. You should drop that down to 2 bearings.