arieck
Member
I've been working on building a hobby plasma table for a month or two and thought it might be fun to document the build as I go. I skulk around enjoying everyone's content here all the time, so I figured it's about time I provide some.
I've always been interested in CNC (I mostly work with metal so specifically, plasma tables, mills, lathes, etc.). Mostly, from a functional aspect... the pieces these machines can create typically could never be pulled off by hand... so the expansion of potential projects I'll theoretically be able to attack with this tool once finished is pretty attractive.
So I started doing research on how I could get my hands on one. Obviously, turn key solutions are very expensive... far more than I wanted to lay out for something that I don't intend to use commercially... so cost was a consideration. The other constraint I had was space. With all of my other half finished projects I have in my garage, I definitely don't have room for a plasma table the size of a small car.
So, considering the above, and enjoying building things myself.... what I ended up looking for was a smaller dimension plasma table that I could build over time, spreading the cost as well as the time involved. After getting some samples of the plan documents and talking with the designer, I ended up getting a set of plans for a 2x4' table from Pierre at Hotrodfab.com. The kit includes very detailed plans in .pdf format as well as laser cut gantry and carriage plates. The end result is supposed to look like this (hotrodfab stock photo).
After ordering the plans, Pierre offered to sell me one of his existing gantry assemblies that he had used in his prototyping (I think he is now offering fully built out gantries as an option), and I figured that since the gantry would be the most fiddly part of the build and not having that much free time these days, I went ahead and bought it.
The plans include a comprehensive bill of materials and when it came to the steel, the dimensions of each. One thing that I ended up doing which has saved a fair amount time, and which was was well worth the extra cost (if any) was to order all the steel from metalsupermarkets.com. I literally just went on their website, selected the material, entered all of the dimensions listed on the bill of materials, and went to their location in Fort Worth a few days later and loaded up all of the (very accurately) pre-cut materials. They ship to your door as well, if needed.
Running list of tools used/needed for this build.
So I had a pile of metal, a gantry, and a set of plans. I set out to building the plasma table top, which is a pretty critical piece and very important to construct correctly. Fundamentally, its just a rectangle made out of tubing, but because it is what is going to both hold up the metal you want to cut and also be the framework upon which your gantry rides, its got to be square and level.
Another builder of this table that I have been following was constructing his table on a very nice layup table called a Stronghand (which I would love to have), but which am happy to report is not strictly necessary. My garage is limited in that I have very few wide flat level surfaces upon which to build things, so I wheeled by toolbox out on to the most level part of my driveway and with a lot of leveling and four HF 90 degree clamps, I got it tacked up.
At this point I realized that I skipped a step which would make things much harder than it should have been. There were supposed to be bolt holes drilled in the tubing all along its length. The bolts support the steel pieces upon which the gantry rides. I'm not one to backtrack, so I didn't go back and cut all of the tack welds out and start over so I did this (which I'm not very proud of, but worked).
The angle iron pieces on the interior of the frame are supports for the slats upon which the work will sit, its important that these get at least semi-installed prior to fully welding the frame up to help against warping inward (which still happened to me, and at least two other builds I know of), but probably would have been much worse if I hadn't. One thing to be aware of is that you will be determining the height of the slats and therefor the height of the work. This is mostly personal preference, but your slats will either sit flush with the top of the table or a bit proud as a result.
At this point, I moved to drill the holes in the cold rolled (for accuracy) steel which support the v-rails upon which the gantry rides. I needed to make sure that these match the tubing holes exactly, so after clamping the rails according to the plans, I tacked welded the ends and then, using the tubing holes as a guide, drilled through the CR rails. Don't start this project without some solid drill bits, there's a lot of steel to be drilled. I grabbed a set of cobalt bits from HF and they performed excellently.
Once these holes were drilled, I cut the tack welds holding the CR rail to the frame, set the rails aside, and went ahead and slowly finished welding up the frame joints, trying to keep as much heat out of the steel as possible. From there, I installed the sheet metal pan which will hold the water (the water cuts down on cutting fumes/particles in the air) by welding a bead around the perimeter, again skipping around to manage heat. I'll be installing a drain and running silicone on the inside of the pan as well to prevent leaks.
After measuring, I noticed that my frame was bowing slightly inwards. If not corrected, this can cause premature wear in your v-rails and bearings. So, I rigged this up and pressed it out a bit.
I forgot to take a closeup pic, but the 32 or so slat retainers (short pieces of round bar) were welded to the slat supports, you can see them sticking up here. Now its time to cut those v-rails to size and get them mounted.
You could probably bolt these v-rails on, but I went ahead and welded them on the ends and a couple along the bottom. Note that if you weld along the bottom you will need to go back and grind the weld flat so that it won't interfere with your gear rack.
At this point, this build thread is caught up with me. Next planned steps are to build the table bottom, and as my CNC control package has arrived, document the installation of those components on the table. I'll also be putting together a component cost summary and adding it here. I'll leave it for now with a photo of the table as it stands.
I've always been interested in CNC (I mostly work with metal so specifically, plasma tables, mills, lathes, etc.). Mostly, from a functional aspect... the pieces these machines can create typically could never be pulled off by hand... so the expansion of potential projects I'll theoretically be able to attack with this tool once finished is pretty attractive.
So I started doing research on how I could get my hands on one. Obviously, turn key solutions are very expensive... far more than I wanted to lay out for something that I don't intend to use commercially... so cost was a consideration. The other constraint I had was space. With all of my other half finished projects I have in my garage, I definitely don't have room for a plasma table the size of a small car.
So, considering the above, and enjoying building things myself.... what I ended up looking for was a smaller dimension plasma table that I could build over time, spreading the cost as well as the time involved. After getting some samples of the plan documents and talking with the designer, I ended up getting a set of plans for a 2x4' table from Pierre at Hotrodfab.com. The kit includes very detailed plans in .pdf format as well as laser cut gantry and carriage plates. The end result is supposed to look like this (hotrodfab stock photo).
After ordering the plans, Pierre offered to sell me one of his existing gantry assemblies that he had used in his prototyping (I think he is now offering fully built out gantries as an option), and I figured that since the gantry would be the most fiddly part of the build and not having that much free time these days, I went ahead and bought it.
The plans include a comprehensive bill of materials and when it came to the steel, the dimensions of each. One thing that I ended up doing which has saved a fair amount time, and which was was well worth the extra cost (if any) was to order all the steel from metalsupermarkets.com. I literally just went on their website, selected the material, entered all of the dimensions listed on the bill of materials, and went to their location in Fort Worth a few days later and loaded up all of the (very accurately) pre-cut materials. They ship to your door as well, if needed.
Running list of tools used/needed for this build.
- Band saw (could probably use a chop saw, but the precision might frustrate you).
- Grinder and disks (cut-off, grinder, and wire brush)
- Mig welder
- clamps (90 degree and reg.) squares
- Heavy duty drill (Drill Press helps) and sharp bits
- Levels Tape Measure
So I had a pile of metal, a gantry, and a set of plans. I set out to building the plasma table top, which is a pretty critical piece and very important to construct correctly. Fundamentally, its just a rectangle made out of tubing, but because it is what is going to both hold up the metal you want to cut and also be the framework upon which your gantry rides, its got to be square and level.
Another builder of this table that I have been following was constructing his table on a very nice layup table called a Stronghand (which I would love to have), but which am happy to report is not strictly necessary. My garage is limited in that I have very few wide flat level surfaces upon which to build things, so I wheeled by toolbox out on to the most level part of my driveway and with a lot of leveling and four HF 90 degree clamps, I got it tacked up.
At this point I realized that I skipped a step which would make things much harder than it should have been. There were supposed to be bolt holes drilled in the tubing all along its length. The bolts support the steel pieces upon which the gantry rides. I'm not one to backtrack, so I didn't go back and cut all of the tack welds out and start over so I did this (which I'm not very proud of, but worked).
The angle iron pieces on the interior of the frame are supports for the slats upon which the work will sit, its important that these get at least semi-installed prior to fully welding the frame up to help against warping inward (which still happened to me, and at least two other builds I know of), but probably would have been much worse if I hadn't. One thing to be aware of is that you will be determining the height of the slats and therefor the height of the work. This is mostly personal preference, but your slats will either sit flush with the top of the table or a bit proud as a result.
At this point, I moved to drill the holes in the cold rolled (for accuracy) steel which support the v-rails upon which the gantry rides. I needed to make sure that these match the tubing holes exactly, so after clamping the rails according to the plans, I tacked welded the ends and then, using the tubing holes as a guide, drilled through the CR rails. Don't start this project without some solid drill bits, there's a lot of steel to be drilled. I grabbed a set of cobalt bits from HF and they performed excellently.
Once these holes were drilled, I cut the tack welds holding the CR rail to the frame, set the rails aside, and went ahead and slowly finished welding up the frame joints, trying to keep as much heat out of the steel as possible. From there, I installed the sheet metal pan which will hold the water (the water cuts down on cutting fumes/particles in the air) by welding a bead around the perimeter, again skipping around to manage heat. I'll be installing a drain and running silicone on the inside of the pan as well to prevent leaks.
After measuring, I noticed that my frame was bowing slightly inwards. If not corrected, this can cause premature wear in your v-rails and bearings. So, I rigged this up and pressed it out a bit.
I forgot to take a closeup pic, but the 32 or so slat retainers (short pieces of round bar) were welded to the slat supports, you can see them sticking up here. Now its time to cut those v-rails to size and get them mounted.
You could probably bolt these v-rails on, but I went ahead and welded them on the ends and a couple along the bottom. Note that if you weld along the bottom you will need to go back and grind the weld flat so that it won't interfere with your gear rack.
At this point, this build thread is caught up with me. Next planned steps are to build the table bottom, and as my CNC control package has arrived, document the installation of those components on the table. I'll also be putting together a component cost summary and adding it here. I'll leave it for now with a photo of the table as it stands.
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