CNC Supplies and Sources

CNC

KnightKrawler owns and operates an OMIO X8-2200L CNC for cutting aluminum and polycarbonate. There are currently 2 sources for this CNC, directly from OMIO CNC and through West Coast Products (WCP).

CNC Software

Onshape for CAD
Fusion 360 for CAM
Mach3 for CNC control

Work Holding

Painter’s tape and super glue are a great way to hold workpieces. Make sure your surfaces are clean and apply tape to both the bottom of the workpiece and the bed (for even better grip, screw an aluminum plate to the bed rather than sticking directly to the wasteboard). Also make sure you either roll the tape with a J-roller or burnish it with a scraper. Apply super glue liberally to one side and accelerator to the other, being careful not to get accelerator on the super glue. Position the workpiece above the bed and press it hard into the bed for several seconds.

When in doubt, screw it to the waste board.

We use two particle board stair treads as our wasteboards, primarily because they are cheap and thick. The 1.125” thickness allows for many more surfacing operations, and for driving longer screws if we need more holding power.

Dakota Ready-to-Finish Particleboard 1-1/8” x 11-1/4” x 42” Stair Tread
Hold-down screws we use: Teks #8 ¾” Length Lath Screws
Predrill holes into the wasteboard and clear the debris, otherwise the wasteboard tends to pucker up and lift the material you are cutting.
Use a screwdriver (not a drill or impact driver) to tighten materials to the wasteboard.
Link to our Wasteboard CAD files.

End Mills

These are the tools we have defined in Fusion 360 to cut aluminum and polycarb on our CNC

(Tool 1) 1/8“ O-Flute Upcut: SainSmart Genmitsu 10Pcs Nano Blue Coat Flat Nose End Mill CNC Router Bits, 1/8” Shank Spiral Upcut Single 1 Flute End Mill Set (3.175 x 17 x 38mm)
A good bit for drilling small holes in polycarbonate and aluminum, can also be used to cut out smaller details such as sprocket teeth.
(Tool 2) 1/8“ Downcut Bit: HQMaster Downcut Bit 1/8” Shank Down Cut Spiral CNC Router Bits End Mill Tungsten Carbide Milling Cutter Set 5 Pack
A downcut bit is an absolute must for cutting thin plastic and rubber, an upcut bit will lift thin materials and cause a mess or worse a crash.
(Tool 3) 1/4“ O-Flute Upcut: YONICO Solid Carbide Single Flute Upcut End Mill Router Bits CNC Spiral O Flute 1/4-Inch Diameter 1/4-Inch Shank 31014-SC Use the 6mm Grewin bits instead) A good bit for cutting out polycarbonate and aluminum, you can be pretty aggressive with this bit.
(Tool 4) 1/4 “ 2-Flute Upcut:1/4” 2FL REG
Great bit for blasting through aluminum, but less forgiving to use
(Tool 5) 6mm O-Flute Downcut: Grewin Cheif Delphi special buy
Excellent bit for cutting polycarbinate and aluminum! Buy as many as you can afford!
(Tool 9) 45 Degree Chamfer: 1/4” 4FL 90° CHAMFER MILL
Tricky bit to get right, but leaves a nice finish
(Tool 10) 2” Surfacing Bit: CNC Spoilboard Surfacing Router Bit 1/2” Shank, by BINSTAK
Scary bit, we usually find the highest spot on the waste board and drop the Z height by 0.02” every leveling pass.

Lubrication and Chip Clearing

We use a mister with 91% isopropyl alcohol to cool the end mill and remove chips from its path. Take a close look at the picture in the link below, there are many cheap misters available, but they use inferior adjustment screws and the “loc-line” can be very loose and not hold the position well. This particular model is sold by many different drop shippers or can be purchased directly from China for cheaper.

Mist Coolant Lubrication Spray System