Hello,
just wanted to share some of our experiments with 3D printing
Omni Wheel based on AndyMark omniwheel design. Have not tried it yet as I run out of filament. Waiting for more filament to arrive.
And downloaded CAD file and printed new AndyMark 48 tooth sprocket, but somehow it does not line up well with the chain (shown with Actobotics Hub):
We will need to experiment some more 
Our 3D printing is much less ambitious, but I am tremendously proud of what my team came up with:
Modern Robotics to Tetrix Sensor mount: http://www.thingiverse.com/thing:1830843
My team is all middle schoolers, but they got lots of help from our experienced FRC team. One of the FRC kids printed them.
Looks cool. I would suggest hosting the files on Thingiverse or Youmagine.
Why not use the Servocity 48 tooth sprocket: https://www.servocity.com/1-50-aluminum-hub-mount-sprockets-0-250-pitch ?
(requires adapter https://www.servocity.com/hub-adaptor-d, but will certainly be more reliable than 3d printed one.)
It’s all comes down to time and money. I can print a lot of sprockets for the same dollars as purchased sprocket with hub and shipping. Also, it’s a lot faster to print sprocket than wait for shipping, avoiding out of stock, shipping , customs and any other delays connected to shipping.
After my original post we have received sponsorship from ServoCity. I ordered few sprockets. But my shopping list was heavily influenced by the fact that we have 3D printer. Things I can easily print did not make it to the shopping list.
I am also trying to get this AndyMark mecanum wheel printed
Run into few 3D Printing related issues. If I am successful, I would definitely post it on Thingiverse
As a veteran, I would just like to add my input. Many 3D printed robots that I have seen in the past, have issues making it when it comes to higher competition. The amount of defensive playing that happens at Super Regional and Worlds is on another level than States (Depending on your state). I bring this up, for my next point.
Any 3D printing you do for sprockets and gears, will fail much quicker than their metal counter-parts. The only luck that my team has had when it comes to 3D sprockets and such, is when it’s used in light-use areas. Using a 3D printed part within the drive-train is bound to fail quickly, even if its printed in solid plastic. I can go back and find pictures if you would like of our sprockets that were turned into ninja-looking stars, from just practice on our field at school, with no defense.
The wheels you listed, that you are trying to print, like to fail quickly when hit. If you are truly going to print them, make sure that another robot can’t get to them.
All in all, we still use alot of 3d printed parts, but in areas that dont have a lot of stress related with them.
I hear you. There is no question, metal parts designed for the purpose will be better than 3D printed ones. But when choice is 3D printed or nothing (when there no money for it) I’ll pick 3D printed.
As for mecanum wheels. I am not sure if manufactured plastic wheel would be that much better 3D printed ones, so I figured both needs protection.
Have you tried 3D printed mecanum wheels?
Finally finished mecanum wheels. I hope they perform well
https://scontent-sea1-1.xx.fbcdn.net/t31.0-8/15003390_338566229843080_5768782559449263721_o.jpg
Next step is vertical motor mount
https://scontent-sea1-1.xx.fbcdn.net/v/t1.0-9/15073305_339103693122667_3444833449525943404_n.jpg?oh=6ef8980f462b65090999bc7e220bdfb7&oe=58C17271