R3 is the third incarnation of the Root CNC. I have been completely blown away with the community which has been created by this project and listening to all the comments and suggestions made – R3 was created. R3 Is keeping to the same design goals as before, but since then a lot has been learnt and areas for improvements been highlighted. There have been many changes implemented on this revision, some radical and some minor though all the changes have been implemented to increase configurability, rigidity, flexibility, accuracy and also reduce the amount of different parts required.
R3 now supports the largest of NEMA23 motors and also the NEMA17s motors depending on the user’s configuration. Its accuracy has also been increased by the removal of the second loop of belt on the Y-Axis whilst still keeping the two side of the gantry still connected together. The second loop of belt introduced a position error when a load was applied to the gantry, now there is only single belt length to increase its positional accuracy. By doing this made it difficult to keep the two sides of the gantry relatives to one another (something another 3D printed CNCs suffer with). Though R3 gantry sides are connected together, so no matter if the machine losses power or is disconnect the machine still stays relevant to one another to keep its running true and square.
Belt or Lead screw? This has been an interesting topic but no matter what your preference is, R3 has provisions for a Lead screws as drive mechanism for both the X and Y Axis. This does require some of your own design work to fit the type of Lead screw the individual is running though the core R3 shouldn’t need any modification and will work with Belt of Lead screws.
Linear guides for the Z axis?! I know theses aren’t considered cheap. But once all the variables and benefits have been factored in, they become a compelling option to use. especially for the short lengths the Z axis requires. With the original design (R2) there was sufficient play in the carriage, due to its minimalist design. Though R3 has attempted to removed or possibility of play with the wood panel and the use of Linear guides. But don’t think this is the only limited to linear guides, R3 keeps legacy support implementing the same linear bearing style design and also legacy Z carriages.
• Create an expandable CNC machine capable to machine aluminium
• Use minimal different 3D printed parts
• Customization (Make it Bigger, Use different motor and drive methods_
• Use parts commonly used in DIY 3D printer
• Easily sourced parts
See R3.zip for the BOM
BOM in embedded in the .Zip File
Animated Assembly guide: Click Here
Where to Download
.stl files can be found on the link- R3 – Thingiverse Link here (Download)
Firmware as software GitHub area coming soon!