DIY CNC Part 3: Y / Z Carriage and Spindle Mount
I received the steel rods from MSC Industrial Supply. Sure I could have purchased the rods from a local hardware shop but I did not want to take the chance on getting rods that were damaged. I ordered 1/4 20 threaded rod and 3/8 precision steel rod for the project. The rods are 36 inches in length and will be used to transport the x table and the y and z carriages. In the previous post I mentioned I made the base of the table to be 36 inches to avoid having to make three cuts. With the rods being 36 inches in length I will only have to cut the rods for the y and z carriages and not for the x table.
For this part of the build I am using:
6 wing nuts purchased at Lowes
misc screws for anti-backlash mechanism purchased at Ace Hardware
1/2 inch quality plywood
wood screws purchased from Home Depot
2 – 1/4-20, threaded rod MSC Part # 06050108
4- 3/8, steel rod MSC Part # 06010243
I tested the rods in the bearing subframes and clamped the machine together to make sure the measurements were correct and the bearing subframes would move freely without binding.
With the dry fit complete I moved onto building the Y and Z axis backplates.
Both Y and Z axis backplates are built with quality 1/2 inch plywood purchased from Home Depot.
After a mock up of the Z carriage I found the bottom Z plate to be flimsy. I modified the bottom plate by drilling a 3/8 inch hole completely through the bottom plate and attaching a secondary piece of 1″ x 1.5″ x 1/2″ wood. The Z bottom plate was then screwed to the inch and a half wood and secured in place on the Y axis backplate temporarily. I will have to install the anti-backlash mechanism and the spindle mounts on the Z axis plate before final assembly.
With everything looking and coming together nicely, it was time to build the spindle mount. The spindle mount was constructed out of 1″ x 3″ pine and cut to the same size as the Z backplate. It was then drilled with an inch and a half hole saw drill on the drill press. Two mounts were made and one was cut in half to provide the upper mount. A 3/16″ hole was drilled along the length of the mount so the spindle can be secured with a zip tie or something similar.
Once the spindle mount was complete, it was time to construct the anti-backlash mechanisms. The anti-backlash mechanisms are used on all three axis to eliminate any slop in the threaded rods.
They were constructed out of the same sheet of plywood I had purchased to make the X table and other parts. Although only three are needed, four pieces were cut so I could clamp two at a time for drilling.
A 1/2 inch hole was drilled down the center of the two pieces. This will allow for the threaded rod to clear and house the wing nuts.
With all the pieces drilled, I assembled the three anti-backlash mechanisms using the wing nuts. I had installed compression springs in between the wing nuts however there was enough tension on the threaded rod I removed the compression springs but allowed for enough tension/room should I decide to re-install the compression spring later.
The next part of the build, I will assemble the X table rods and install the gantry.