A few things I learned in hindsight... I should have made the Y axis rails extend beyond the end of the water table enough so the torch head could reach all of the water table. A little more Z travel would have been nice. My slats are not rigid enough to keep thin material from moving when cutting at high speeds so I have to clamp it down to a frame rail with a piece of scrap.
I don't have a downdraft table but I assume you will have to move huge amounts of air to capture the dust from the plasma. Quite a bit of the dust flies up from the cut point so to be efficient the table will need to be completely enclosed to capture the dust. The amount of dust depends on the material condition as well. It seems to me that the more rust, crap, and dirt on the plate the more dust I see. A marking device like a spring loaded center punch with a pneumatic cylinder to push it down would be a nice addition if the plasma cut parts need any machining like drilling after cutting. That would save the second op a ton of time in not having to lay out holes. John On 6/27/2012 11:18 AM, Viesturs Lācis wrote: > Hello, folks! > > I have 3 small things. > First one is a question for any useful plasma-specific tips, when > designing plasma cutting machine. I just got a contract for building > one and I would appreciate a chance to learn from other people's > mistakes rather than my own. > Following things are on my to-do list: > 1) use shielded cables for encoders AND for motor power; shield is > grounded only on one end of cable, most probably the drive end; > 2) connect the machine frame and all the moving constructions and > everything possible to earth grounding; > 3) route plasma cable separately from motor/encoder/signal/whatever > cables wherever possible; > > I would appreciate, if plasma machine owners could share their > experience and some problem areas they have encountered, when > designing their machines. > > Second question - I would appreciate some advices for good and > efficient downdraft table design. I have one brochure, where one > concept is shown, but, guess what, it is not very detailed. So maybe > there is some webpage with useful information on this matter. > > And last one - I would like to share a video of Anthony's 5 axis > plasma cutting machine. I think that he has built very nice machine > and I find his design of the rotary head to be very interesting (well, > take a look at other of his videos for some closeups). Actually it > showed me a solution to the problem I encountered, when designed the > head for the waterjet. > I helped him out with 2 kinematics modules: > With the first module the machine can take the angle of torch tilt, > given in the g-code as A word, and keep the direction of the tilt > perpendicular to the XY movement. I do not know about plasmas, but for > waterjet this concept handles the kinematics for taper compensation. > The second is "usual" 5 axis module, which compensates for torch > length offset along x, y and z as the torch is rotated by rotary > joints. > Both kinematics modules will also adjust torch height along central > line of the torch instead of just moving along Z, which is crucial for > 5 axis cutting. > > The video shows the taper control module in action, running a > testcode, consisting of 2 arcs. > http://www.youtube.com/watch?v=myNtcNJBcTA > ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
