In short the laser cutting table, presented in this article, is made of two pieces of 1" square aluminum tubes held together by three 3/8" bolts, Kanthal wire used for providing actual surface for the table, a ruler and few 3/8" nuts. The bolts used for both: holding two tubes together and tightening the wire.
I have bought a 50W CO2 laser cutter/engraver with 50cm x 30cm cutting area from eBay a while ago and I needed a good cutting table for cutting acrylic, plywood, paper and engrave on those materials as well. While I was thinking about the table, I was cutting all the material using my laser cutter's flat surface and sometimes chopsticks as well ;-) These were not very good solutions at all, as it was inconvenient, could not hold work pieces in place and created marks on material backside due to beam reflections. I have read many reviews about pros and cons of many different solutions. I've found that a very popular honeycomb table doesn't vent very well as each cell is separated by its own walls and I feel that honeycomb core itself has lots of ribs/metal in the path of a laser beam. I have looked at lamellar cutting tables as well, which are in my opinion is the best solution, but ready-to-buy solutions are just a few; they are pricey; and good lamellar core itself is pricey as well. I have also looked at egg-crate cores and found that it has few flaws as well, such as separated square cells, similar to honeycomb core, and lots of ribs/metal in the laser beam path similar to honeycomb core. I have done some thinking and reasoning for a while and came up with few ideas. Please take a look at all the attached pictures so you have an idea how it looks like and what is involved. I've also included a couple of pictures of cut paper, look at the picture where I placed a really thin cut paper next to a ruler. I was impressed as there are no any marks from reflections. I don't think I have to include any in depth information on any of the tools, materials and techniques, except one. For this project I've used Kanthal wire, which has few important characteristics and one of them, which is really important to us, is its melting point of ~1400°C. I created my laser-cutting table; tried it for a short time; really liked the results; and decided to share with others. I have learned few things from makers on the instructables website and want to share my ideas in order to give back to the wonderful community of other makers. Therefore, if you are in need of a good laser-cutting table; have few hours of time; have access to all necessary tools; an urge to make it yourself; and want to save some money, the instructable is for you.
• no burn marks on back sides due to reflections
• good ventilation
• availability of materials and tools
• easy to recreate for others
• 1" aluminum square tube (~$22 for 8' at my local hardware store)
• 3/8" long bolts - three bolts ~16" each (~$2.50 for 4' at my local hardware store)
• 3/8" nuts - 12 pieces (~$1 for a pack of six in my local hardware store)
• 24 AWG Kanthal wire. Spool of 100' (~$6.50 on Amazon website)
• Aluminum ruler of your choice (~$3 in my local HF)
• Small metal screws to screw the ruler to top tube. Your choice. I've used what was available at my garage
• Band saw. I have used stationary band saw
• Drill. I have used my drill press
• Orbital sander - optional to make everything look nicer
• Center punch
• Permanent marker
• Rotary tool with diamond cone attachment
• cut two pieces of square tubing to 54.5cm and 52.0cm
• align tubing pieces together (both aligned on left; longer tube is upper one or oriented closer to my laser home position; shorter tube is lower one); clamp; mark the tubing 5.5cm from the left side, where both tubes aligned, and 8mm from bottom; center punch the mark; drill the first hole through both pieces of tubing
• insert 3/8" bolt into the hole; use two 3/8" nuts; and bolt the tubing pieces together in order to keep good alignment for drilling the next hole and just to keep your work pieces aligned
• align the opposite ends of square tubing together - would be easier as the pieces are held by 3/8" bolt on the opposite side; clamp; mark the tubing 3cm from the shorter piece of tubing end and 8mm from bottom; center punch the mark; drill the second hole through both pieces of tubing
• insert 3/8" bolt into the hole; use two 3/8" nuts; and bolt the tubing pieces together for good alignment for the third hole drilling and just to keep both tubes together for other steps
• now both pieces of tubing are held together by 3/8" bolts and nuts; mark the tubing somewhere in the middle, but 8mm from bottom to keep all bolts in alignment; center punch; drill the third hole through both pieces of tubing
• keep both pieces of tubing bolted together for other steps
ATTENTION. Read carefully before continuing to next steps. Now we to use band saw (hand held band saw and or even hack saw could be used, but you will have to be more creative) to create cuts on the surface of tubing. The cuts have DIFFERENT depth on one side of the same tube: the cut facing actual laser cutting area should be less deep and the cut on the opposite side of the same tube should be deeper for two reasons. If cuts are too deep at the side facing laser-cutting area and you cut, let us say, a sheet of paper, the laser head have to be lowered in order to concentrate the laser beam on your work piece and if the table is not properly placed, the laser head may hit the tube or ruler on top of the tube and may break. The reason to have deeper cut on the opposite side of the same tube is used to secure the wire and you will see why in one of the final steps. I have used stationary band saw and it was easy to create the cuts, I intended. If you use hand held band saw or hack saw, you need to be a little more creative. When I have raised the stopping bolt on my stationary band saw, the degree of cut changed horizontally so on the side closer to the band saw motor, the cuts are deeper and on the side away from the band saw motor, the cuts are less deep. My tubes have 4mm cuts on one side and 2.5mm on the other. Keep in mind that the Kanthal wire is 24AWG, which is ~0.5mm. So theoretically you need cuts more than or equal to 0.5mm on the side facing the cutting area. I have used 2.5mm.
• Now you have two tube pieces bolted together by two 3/8" bolts and nuts. Take ruler and start making marks 15mm apart. My first mark was at 15mm from left upper corner, which is my laser cutter's home and my last mark is at 510mm point.
• For actual cutting, you will need to move 3/8" bolts so you may continue to cut tubing. Keep them bolted all the time so your table looks nice.
• Adjust stationary band saw to the proper height (raise band saw; clamp tubing few mm away from actual saw blade; lower band saw; adjust height so blade will stop at ~4mm at the closer to the blade side and ~2.5mm at the opposite side of first tube. Two tubes remain bolted together). Start making cuts and change bolt positions as needed
• reverse tubing and repeat cutting process so both tubes have identical depth cuts (the outer cuts ~4mm and inner ones ~ 2.5mm)
• Take rotary tool with diamond cone attachment and touch cutting edges on the outer side of tubes. It will help to secure and hold your Kanthal wire secured. When you wind the Kanthal wire, it just stays in those little holes.
• By now, you have two pieces of tube with holes and all the cuts. Insert bolts and secure upper/longer tube in place. See attached pictures. Secure upper tube (closer to your laser home position) by tightening nuts securily together as you will not use those bolts in future. Put nuts in front of lower/shorter tube; place tube; put last set of nuts (from upper to lower side: nut-upper tube-nut- actual cutting space -nut-lower tube-nut). Both tubes aligned at left and lower tube is shorter on the right side
• Measure and adjust upper and lower tube positions to 34.3cm, measured from most outer surface of upper tube to most outer surface of lower tube and tighten the lower/adjustment nuts.
• Wind your Kanthal wire as shown in attached pictures. Use mechanic gloves, I have used just right glove and helped with left hand. I secured the beginning of my winding by a knot; see attached pictures, and the other end of wire by outer adjustment nut and washer.
• Done. Tighten your wire by turning your adjustment nuts clockwise. Use 1/4 of turns starting from one side and going to opposite; repeat if needed.
I will be happy to clarify any steps or answer any questions, you may and should have. Thanks for reading the post.
This instructable is a part of the Full Spectrum Laser contest. If you find the instructable useful, please vote for it by clicking an orange "Vote!" mark at the right upper corner of the instructable. Thank you in advance.
Best regards. Vlad