However, before building your own, make sure to gain a basic knowledge both of how a CNC machine operates and of its components. If you do not have the time or knowledge to devote to building your own, you can peruse the wide selection of CNC mills available in local hardware stores or on eBay instead.
What You Need to Build a CNC Mill
When purchasing components to make your own CNC mill, you first need a frame. To create one, you can use water pipes along with three 90-degree elbows and a tee. In addition to the frame material, you need the following: something to mount the dremel assembly to the top of the gooseneck; 10 3/4-inch aluminum U channels of varying sizes; three stepper motors with brackets; three 1/4-inch x 20-inch threaded rods; three small rubber hoses; three pieces of plexiglass; washers to use as spacers; seven bearings; nine 1-inch x 2-inch pieces of aluminum with holes drilled in both ends; three 1-inch long 1/4-inch nuts; four posts to hold the dremel tool; a cross-post and a bracket to hold the dremel in place; a control unit; and numerical control software to use on the computer.
Begin by building the framework for the CNC mill using the water pipes. Create the base of the frame in a U-shape using the 90-degree elbows, and use the tee to make a gooseneck to hold the Z-axis of the mill.
For the X-axis, mount the longest of the 3/4-inch aluminum rails to the pipes. Then, attach a stepper motor between the rails to one of the pipes and connect one of the 1/4-inch threaded rods to the motor using a short piece of rubber hose.
Take a piece of plexiglass and mount a piece of aluminum channel to it. In addition, attach one of the bearings to the plexiglass using one of the 1-inch x 2-inch pieces of aluminum. This bearing should run along the inside of one of the aluminum rails attached to the frame, and the aluminum channel attached to the plexiglass should run along the outside of the same rail.
Wrap a piece of aluminum around one of the 1-inch long 1/4-inch nuts and attach it so that the nut sits in the middle of the plexiglass and runs along the threaded rod.
For the Y-axis platform, mount two aluminum channels to the top of the first piece of plexiglass. Then, mount a channel to the bottom of another piece of plexiglass with a notch cut into it, in addition to another bearing and a coupling nut attached to a threaded rod. The rod, in turn, attaches to another step motor via a rubber hose.
Next, attach the step motor to a piece of plexiglass that is separate from the Y-axis platform. The notch in the plexiglass allows the Y-axis platform to move around the motor, giving it a better range of movement.
For the Z-axis, use another piece of plexiglass and mount two rails on top of it. You should also mount a step motor to one side.
Next, take another piece of plexiglass and mount both a U-channel to it and a roller bearing to ride against the bottom rail. Since the threaded rod runs on the top of the second piece of plexiglass in this step, you should attach the coupling nut to the top piece.
Add two extra bearings, one on each side, to help to keep the entire assembly in place. This keeps the Z-axis from detaching while moving.
Attach some posts to the top piece of plexiglass on the Z-axis. The dremel tool sits in between these posts, held in place by the cross posts and the bracket. Once it has been assembled, attach it to the top of the gooseneck, and finally, attach the CNC mill to a control unit and connect it to a computer with the appropriate software.
How to Buy CNC Mills and Supplies
You can find both pre-assembled CNC mills and the supplies needed to build them on eBay by performing a keyword search. This includes a variety of different types of mills, such as end mills, drills, reamers, and more. When searching for CNC mills and supplies, look for those that can perform the functions you need, while also making sure to purchase any tool bits that you need as you shop. Building your own CNC mill allows you to customize it to the size and range of motion that you want, giving your mill the ability to aid you in a wide variety of functions.