I found this project and was immediately intrigued. Over the past couple weeks I’ve spent about fourty hours going through the design in an effort to make this car the best it can be. I have a RigidBot big printer, which can print up to 16" X 12" X 10" parts, so I made a single piece chassis. I also centered the central differential, flipped the motor around to allow for saddle battery packs and streamlined the servo linkage. I’ve modified all the parts that are a lighter grey in the attached image.
I was planning to buy the metal gears suggested by others that fit this chassis, but am now thinking about finding a better central differential with a slip clutch incorporated, like the one in the team associated B44 buggies. Has anyone tried this yet?
Looks awesome. Have you printed it? File link?
I’ve printed about 1/3 of it - working on the main chassis right now. I’m holding off on publishing it until I’ve tested the new design.
Are you going to publish the .stp of your build? looks great!
Nice idea with the saddlepacks, good job! =)
Is anyone working on a rock crawler or other off-shoots? My openRC is SO FAST I can barely control it. I break something every time I drive it. My son is dying to try it but it’s just way way too fast.
I’m thinking about a version that is super strong, all triton?.. Maybe an aluminum roll cage or bumper to put my water jet to work. I may just make it really big or maybe use 608 bearings and big beefy everything. I need something my son can drive 
Btw- if any talented 3d designers out there want to design some water jet parts for reinforcement… I could send some free prototypes out if you prove you have a running car. I have a bunch of 1/8" aluminum from reject parts. What I really want is to do the gear boxes in aluminum on my Tormach… But my skills aren’t there yet.
I’ve also dreamed of printing the full body of some actual car models on my Printrbot Go Large.
The cool thing is my son hasn’t taken to 3D printing yet, but he LOVES to play with our RC cars… And his favorite is the openRC.
@Brook_Drumm : I too want to make a durable truggy. I’d be interested in making an aluminum chassis after I get the bugs worked out of my new design. I’ve also been experimenting with printing polycarbonate, which can be very strong. I have a role of carbon nano tube infused abs coming soon as well. Do you have the tools to heat treat your aluminum? I’ve never been too into rock crawling, but I can see the appeal for this kind of project. You’d have to buy your front and rear worm gear differentials, as 3d printing them would be very difficult to get smooth (unless you went with SLS prints). I founded an engineering product development company in CA (http://uptronics.com) and have been designing/building all kinds of Mechatronic products for the past few years. A water jet is on my wish list of prototyping tools, right after an SLS printer 
Cool! I can heat treat. I can print polycarbonate, triton, whatever. I have sls printers too. I can buy whatever I need. Durable truggy first, Rick crawler later. Feel free to email me. Brook at…
@Tyson_Messori I race a very high end 4wd buggy and actually eliminated the slipper for a center diff. IMHO you’d be going backwards to incorporate a slipper in this one.
We are also moving away from saddle packs and going with shorty lipo packs. At last that’s the trend in the race world.
Also, be careful about flipping the motor around. The rotational momentum of the motor will significantly change the handling of the vehicle!