The project, not the actual laser cutter, but progress is once again being made. I live in Houston, TX and unfortunately, we only have two seasons; mild and ball-melting hot. We get mild from November to February or March and then ball-melting hot for the next seven or eight months. Since my garage is practically a functional furnace, I can’t do much work out there during the hot season. We’ve been enjoying some cooler weather the last couple weeks and I decided it’s time to start work on the cutter again.
When we left off, I had gotten the majority of the frame assembled and had collected most of the parts needed to complete the table. Due to some design changes, I had to order a few new frame pieces and other little bits and pieces. The first box of parts was either delivered to the wrong address or stolen off my porch. The first thing I did was put the lid together and mount it on the rest of the frame with a 36″ piano hinge. I still need to find a couple hydraulic pistons to keep it open but that won’t be necessary till near the end of the build. I replaced the two lower 20mm cross supports with 40mm pieces instead. This was necessary for better mounting of the z-axis lower brackets as you’ll see in the pictures later.
The next logical step was assembling the z-axis. The table is just a rectangle of aluminum frame. It has four brackets sitting on t-nuts that ride on 4 threaded rods. the rods are run through a bearing captured in a bracket at the top and the bottom of the frame and held in place with a nut on top and an XL pulley on the bottom. The assembly was actually a little challenging because everything has to be sort of pre-assembled together and put in place. I ended up mounting the top and bottom brackets on the frame and the table brackets on the table; all relatively loose to help with lining everything up. I laid the belt on the brackets since the four threaded rods needed to be inside and the belt isn’t open. I put a pulley on the bottom of each threaded rod and threaded a t-nut halfway down. I then put the table in the center of the frame, slid each rod up through the table bracket and into the top bracket on the frame until the bottom would slide into the bottom bracket. It was a bit sketchy with just the first corner and I was worried about bending or breaking something so I awkwardly held the table as a did the other three rods the same way. once opposing corners were done, it mostly supported itself and wasn’t that bad. once all four rods were in place I screwed a nut on top of each one, loosened the pulley and let the rod settle. Then it was just a matter of threading the belt around the pulleys and bearings, lining up each pair of brackets, getting them all in to position and tightening everything. I leveled the table and then tightened all the pulleys. All in all it turned out great and it has a nice smooth movement up and down when I pull the belt.
I did some basic test-fitting of the x/y axis as you can see, but I bought a new piece of extrusion for the gantry so I need to drill and tap it and transfer the rails over before I can assemble anything else. I’m happy with the progress I’ve made so far and I am starting to think about what I want to cover the frame with. I may just end up running it open for a bit, I haven’t decided. I hope to finish the whole table up in the next month so I can start working out the kinks with the computer and motor controllers and think about things like air assist, ventilation and cooling. I may even get the laser tube and power supply ordered before the end of the year, who knows. Progress should be much more rapid than it has been so expect more posts soon.