CNC Plasma cutters, DIY, building info and guide

lots of ways to do it
without air soker it is not workabel over 15min

and a water bed is the best to keep all things clean
5mm below part it is good the spray can cool the part down
with at least 2inches of water at 100+Amps
1inch at 50A

Usually i have 7cm (3") from the material and another 3 to 4cm (1 to 1.5" roughly) above the material.
Usually the water level is up to the material or a bit under, but i very often fill above the material so the torch nozzle dives in and fires under water and cuts under water. This way i get no smoke at all.
Usually when i do that i hear a lot of people screaming that it is not possible or safe or many other opinions, and that is always nice for some laughs.
All the plasmas i [strike]have[/strike], hmmm, had work under water.

rodw wrote: [Anyway, it will be pretty trivial with mesa cards providing enough outputs. The beauty of LInuxcnc is its so extensible. Here is all the code you need for 2 zones utilising a 2 position flap so 4-6 zones would not need much more.

pin in float position "Motion signal for Axis position";
pin out bit trigger "True if downdraft segment should be triggered";
param rw float cutover "Absolute axis coordinate above which triggers zone change";
...

You could have just used the "comp" HAL component, or maybe "wcomp"

Just wondering if anyone had considered using coreXY for a plasma table. Since Tom is suggesting using GT2 belts for the smaller machines, a coreXY setup would eliminate some of the moving mass of the gantry and potentially help with acceleration. My concern would be the durability of the GT2 belts with respect to the sparks from the plasma torch. In a traditionally driven machine, you can place the belts so they would have minimal exposure but I'm not sure how you would do that with a coreXY machine. Am I too worried about the belt durability? Have I missed an easy way to protect the belts?

you can go with cheep ballscrew as of 12m/min up to 1m table 80cm cat area

then considder Rack pinion with 1:5 gear cheep and good for 8m/min cuts

the Timingbelt woudt be a AT5 the best to use no flex on 10m Width 750KG of tention

my 4 plasams and the 5th are on Rack pinion with 30:1 wormgear at 3Nm 72V
running 20m/min at 0,1mm/step
this is the setup tighten with a spring to the rack
it runs for a full shift with no steploss at 8m/min cut G64 P0.3
Double shielded ROBOT Cable 4x 0,75mm² in e-chain length 12meter at 72V 4,2A M880 7i76

Hi

If you read on some of the 3D printing forums you will find that corexy has it's own set of implementation challenges. Plasma cutting is dirty and does throw hot slag bits around so all belts need really good protection. Rack and pinion is cheap, easy to get and pretty forgiving of all the plasma debris that will be around your table. If you are going to be cutting 1.5mm or thicker you should have no problems with getting high enough speed with 3NM steppers and a power supply of 48V or greater. Your Z axis assembly with float switch and torch will be heavier than you first think. A rule of thumb I once heard for stepper driven plasma is to have your total reduction so 1 revolution of the stepper yields about 25mm of travel on your X and Y axis. Mine is a little less than that but within an order of magnitude.

John