Yes and so can you!
Yes, you can probably reuse your existing CNC machine's Nema23 motors, controller and other electronics to build your PrintNC.
The NEMA23 version is recommended for anyone building from scratch.
The current version is version 3.
The PrintNC STL files are available for two frame cross sections:
75 mm x 50 mm for metric countries
3 inch x 2 inch for imperial countries
STLs can be generated for other cross section dimensions by modifying the publicly published STEP files or requesting custom STLs for a small fee in the store.
The linear kit for sale in the store provides an approximate working area of 1050 mm x 650 mm x 100 mm (41” x 25” x 4”)
Larger or smaller can easily be adapted without sacrificing performance.
First of all the orientation of the X and Y axis (x wider than Y axis) in the standard size PrintNC was chosen to give you a better access to the work area without limitations to the rigidity. When scaling/planning the PrintNC workspace larger it is better to change the orientation in a way that the Y axis is the longer one, both to avoid loss of rigidity and avoid chattering. Going with the X workspace being larger than 1000mm (39") will, depending on the weight of the used Z assembly (used spindle etc.), most likely cause a bit of sagging in the X steel beam and the chance of bending forces in the Y direction. In that case increasing the thickness of the X steel beam can avoid this to a certain amount. As seen in many other CNC designs planning/building the PrintNC in extreme dimensions will need some practical experience. Trial and error will be more the exception in the mainstream sized builds.
Use a taller steel tube on the y axis and/or use a taller tube in the gantry rollers. Standard is to use a 75mm but there are some people out there using taller than that. You will have to take into account the possibility of a reduction in rigidity from having a taller gantry though due to increased lever.
If you want a bit more to start with and are willing to deal with the increased deflection caused by the longer lever arm, then just change your Y steel to 100x50 from 75x50 and that'll add 25mm extra.
The machine can be built for approximately what the current kit shown in the Three Design Store plus the steel and some additional components like (a controller, an electronics enclosure, and some other electronic components). The kits keep evolving (they are including more items) so this is a bit of a moving target. Steel could cost varies by region. (if the price is different, it could be because some components have been added/upgraded)
Christoph Lehner has put together a great video covering the typical costs involved in a PrintNC build here: https://www.youtube.com/watch?v=5BvZuybBrjU
Search YouTube: NycCnc, Winston Moy (probably the most apt for our size machine), and This Old Tony.
See also carbide3d channel which is also hosts a lot of videos also produced by Winston as he works for them.
Steel is ~3 stiffer than Aluminum. Wall thickness recommended for steel section is 2.5mm (0.1″)
Do not go thicker than 5mm or 0.2″.
Call a local steel supplier for various options/thicknesses before proceeding.
Yes, a machine that is deeper than it is wide is the best way to maximize rigidity. However, the PrintNC design is incredibly rigid and the benefits of having a wide machine outweigh the inconsequential loss in rigidity.
HGR rails and carriages by design are quite tolerant of inconsistencies in the mounting surface and mounting accuracy. This aspect of their design is different from many smaller standard rails such as MGN12 and is one of the reasons they were chosen for the PrintNC. HIWIN spec for HGR20 rail allows for 0.13mm of variation in the mounting surface while still remaining within the design and performance specifications for long term reliability in high duty cycle commercial environment at maximum load. HGR20 rails are also vastly over-specified for the gantry weight and any cutting forces that the PNC generates so we are working at the bottom end of their performance envelope which extends service life and reliability.
The use of 1 block per rail is a conscious design decision made after numerous iterations of the machine.
Adding a second block WILL increase the useful lifetime of your rails, however, we expect the useful lifetime on a single block will be more than adequate. HGR20 rails are overkill for a CNC router experiencing these loads. In addition, usage of a hobby router is a fraction of continuous duty machinery (for which the rails are rated)
The numerous benefits listed above, including reduced upfront cost, far outweighs the low risk and number of incidents of wear (currently 0). Rails are now inexpensive enough to simply replace them if the time ever comes.
The PrintNC is an open-source design that encourages modifications to suit your needs. You can certainly add a second block or switch to long-style blocks, if you so desire.