greenBull 5' or 6' Wide CNC Machine Kit v4.1
Here is our largest CNC Machine Kit intended for larger sheet sizes or large 3D carving ability. The CNC Machine can contain a torsion box table for sheet stock milling, or a frame for 3D carving. The CNC Machine will feature two main travel sizes: 5'x10' (60'x120' or ) and 6'x12' (72"x144").
The following refers to the length of the z-axis.
Short-Z - intended for machining of sheet goods or relatively thin materials.
Long-Z - intended for large format 3D carvings.
See below for more detail. Call us (281-213-5643) to let us know what size spindle/router mounts you need on the machine.
Optional torsion Box Table:
Purchase Optional Torsion Box Table Here. This machine features increased sizes overall for stability along these new travel length, NEMA 34 motors on all axes, new dust shoe design for better suction and clean-up and a modular torsion box table for your desired length. The overall design has increased rigidity for the new routing/milling area but still maintains the aesthetics that are common across all of the machines on this site.
The small dimension (5' and 6') is the measure of the travel along the gantry. The length of the table is the other length which can actually be lengthened by purchasing more table modules.
To insure that the gantry doesn't flex at all, a series of ribs were added within the gantry box making the entire gantry very similar to a torsion box. The gantry also has an increased height to bring the v-groove bearings farther apart. Increasing the distance from the top v-groove bearings from the bottom v-groove bearings increases it's resistance to flex and with the ribs within the gantry, the entire gantry assembly is very tough. Additionally, the x-axis motor that is mounted within the gantry structure uses 1/2" steel shafts from the motor to the gantry sides. The 1/2" shafts are coupled to the x-axis motor with steel rigid couplings. The steel rigid coupling offer much more strength in high torque situations.
The motors selected for all of the axes are NEMA 34 with 1/2" shafts (driven by 6.0 amp drivers). With new shaft used for the X and Y motors and the 1/2" shaft extensions on the x-axis, the sprocket for the mechanics needed a 1/2" bore, which increases the number of teeth for the sprocket to 14 teeth. At 1/16 microstepping, this yields ~914.28 steps per inch. At 1/32 microstepping, the steps per inch would be ~1,828.57.
The dust shoe is redesigned to provide better dust extraction capability. The dust shoe redirects the blower air from the router (blowing in the downward direction) towards the side of the dust shoe so the space under the dust shoe has almost total suction. In the image, you will notice that under the router, only the collet appears. A plastic liner, or a flexible strip brush can be adhered to the perimeter of the dust shoe to contain the suction so all of the dust is extracted and is directed into the vacuum. This is the most successful dust shoe created on this site, and works very well.
The electronics that can be purchased with this machine consists of three large NEMA 34 Stepping Motors, three 6.0 max amp drivers, breakout board and power supply.
For Machining Sheet and Low Profile Materials:
Also called "Short-Z". If the desire is to machine sheet goods, the optional torsion box table can be purchased . The torsion box table is sold separately for this CNC Machine. The table is sold as modules for the final desired length.
The thickness of the material is measured from the table bed to the lowest part of the gantry and then subtracting the end mill length and spoil-board (the board that protects the table bed surface). The length from the table surface to the lowest part of the gantry is 5.75". If an end mill with a cut length of 1" is used (with about 1/4" shank extending from the collet) and the spoil board is 3/4", then the material thickness can be up to 3.75". Here is how this number was derived: 5-3/4" - (1-1/4" + 3/4") = 3-3/4"
For Machining Large 3D Carvings:
Also called "Long-Z". If this CNC Machine will be used for large 3D carvings, a custom frame will be needed (shown in Illustration to the left). The frame should be made with square tubing, or well constructed lumber to allow for freedom of depth within the travel lengths; however, understand that the travel will be restricted by the frame, where the z-axis assembly conflicts with the frame intended to support the v-groove bearings attached to the gantry sides. To provide for the extended z-axis depths, very long z-axis rail support pieces are included. The support pieces allow for a 36" of z-axis depth of travel. When this assembly is selected, precise frame height will be required unless high ceilings are present.
To determine the frame dimensions, first consider using the frame height shown of almost 3' (2.86'). The width of the frame should be 4" narrower than the dimension from rail edge to rail edge (5X rail to rail is 67.3587" and 6X rail to rail is 80.078"). This will provide a 2" overhang on both sides (5X frame width should be 63.3587", and the 6X frame width should be 76.078"). The length of the frame should be 4" shorter than the desired length of the rails to provide a 2" overhang on both ends. The travel length will be 20" shorter than the rail length due to the space occupied by the gantry sides.
Two long pieces of 3/4" material will need to be placed on top of the frame with the 2" overhang on the sides and the end. These long strips of material will receive the rails and the chain mounts on the ends.