As part of our off-season work our team (1965) has spent some time experimenting with 3D printing. Last year we experimented with building a complete tank track to learn about how robust 3d printing could be. This was installed on a robot and displayed at the 2015 championships by PTC ( one of our team sponsors ). We created a blog for this: FIRST Tech Challenge: 3D Printing for FIRST Teams (1 of 8)
This was very successful for us and proved to be really robust. Therefore, we are thinking of using a version of this on our robot for Stronghold. Attached I have included the blog article and all of the models ( in PTC Creo ) for the tank track, drive sprocket wheel and the tutorials. Included in the doc is our BOM for the tank, we used a combination of parts from McMaster-Carr, AndyMark and BaneBots some of which have been discontinued.
There were some important lessons learned along that we documented in the blog. Hopefully, you will find this helpful. You should note that it will take quite a while for you to print out all of the parts for this. A single drive wheel ( the 2 parts ) took us 19Hrs, 25 of the threads took 20Hrs. We used the Makerbot Replicator 2 for this work.
I will echo Brandon’s comments regarding traction. Is it possible that you could post a video of, say, a kitbot pushing your tank track-ed robot around?
You are correct the plastic is pretty useless on carpet from a traction perspective. The threads themselves have recessed rectangles on the bottom.
These were included after our first attempt so that we could glue strips of
a Gates drive belt ( from the KoP ) to increase the traction. We just started
experimenting with this last weekend and so far it looks pretty good.
Attached is an image of an early experiment where we just glued belt
strips to the flat threads, they were easily sheared off so we added the
recesses.
On the static question, that is a good point. We have not had any issues
or noticed any static buildup and we do always trail a static strap. I will
definitely look at that closer, all of our testing is on carpet.