Being exiled to the garage for five days has given me the time to make some good progress on my DIY CNC. What started out as what I thought would be a simple build of the X table turned into somewhat of a project in itself. Remember that “quality” plywood I had purchased for the table? Well it turned out it had a bow in one of the corners and I was not able to use it. I had to replace the “quality plywood” with some MDF from Home Depot. A bill of materials is located at the bottom of the page.
I had originally thought if the X table was smaller then I wouldn’t have to worry about the bow in the table or the little “wobble.” There was a minor wobble in the X table when applying pressure to the Y axis. I decided having a slight bow in the X table and a little wobble will cause problems later when cutting, so I replaced the plywood with the MDF.
Once again I had Home Depot cut me a piece of MDF and I was ready to install the X Table. To give the X table a little support, I decided to install some supports as the MDF was quite a bit heavier than the plywood and I don’t want the rods to bend or the table to bind. I installed four small coaster wheels I had purchased from Home Depot when I got the MDF. After the installation I noticed the wheels were oblong and creating the X table to bind up along the axis. This would make it hard for the stepper motors to move the table so I removed the coaster wheels and just put a nice piece of pine underneath the X table. I countersunk a few holes and screwed my newly created X table supports into position, tested for binding and proceeded to square up the X table and Y axis.
Once the X table was complete and without any binding, the final assembly of the gantry was next. I needed to make sure the Y axis was exactly square to the X table along the full length of the Y axis. I used a speed square to check and make the adjustments. Once I was satisfied with the Y axis being square to the X table all along it’s axis, I screwed the Gantry down on both sides of the frame and checked it again to make sure the Y carriage would transport across the Y axis without binding.
At this point I thought I’m basically making a printer! It’s looking like a printer anyway… With the X and Y square to each other, the Z will also be square to the X table. I had squared Z to Y when I constructed the Y/Z backplate.
Checking the X, Y, and Z axis I noticed the X table was slightly touching the clamps I had purchased to secure the 3/8 steel rods. I trimmed the little rubber off the top so it was flush with the metal clamp and this provided enough clearance for the X table to move freely without touching anything other than the X table supports. Was it time for a beer?
With the machine pretty much constructed, I moved onto getting the stepper motors prepped for installation. The stepper motors will be attached to the 1/4 20 threaded rod and transport each axis.
On the next post, I will go over the NEMA motors, the NEMA motor driver modules, and where I sourced those materials. Yeah, it’s time for a beer or cough syrup. Until next time,
Bill of Materials to mount the steel rod on the X Table:
4 each – Vibration-Damping Clamp with SBR Rubber Insert, Zinc-Plated Steel, for 3/8″ OD, 3/8″ Tube Size McMaster Part # 8981T62