CNC Plasma FAQ
DIY control systems and retrofit kits
What is a CNC plasma retrofit kit?
A retrofit kit replaces the electronics on an existing plasma table: the controller, stepper drivers, stepper motors, power supply, wiring and control box. You keep your frame, gantry and plasma cutter. It is usually the most cost-effective way to bring an older or unreliable table back to life.
Will your control system work on my plasma table?
CNC X WRIGHT kits fit most entry-level to mid-range CNC plasma tables, including original Wright CNC tables, Wright-style tables from other builders and most DIY builds. Motor shaft size, mounting and wiring vary, so send us your table details or book a diagnostic session before ordering.
Do you support Wright-style tables built by other manufacturers?
Yes. Many tables on the market share the same basic layout, motors and electronics as the Wright designs. We can repair, upgrade or fully retrofit them with new controls, motors and torch height control.
What comes in a CNC plasma controller kit?
A pre-wired control box with the controller, stepper drivers, power supply, E-stop and main power switch, plus stepper motors depending on the kit. Options include automatic torch height control, homing switch kits and communication cables for Hypertherm, Everlast and PrimeWeld plasma cutters.
Mach3 or MyPlasm: which control system should I choose?
Mach3 uses a standard G-code workflow with SheetCAM and is very flexible. MyPlasm by Proma Elektronika has built-in torch height control and ohmic sensing with a simpler, drawing-based interface, a good fit if you would rather not learn G-code. Not sure? A 1-hour diagnostic will point you to the right one.
What software comes with your kits?
Mach3 kits can include a pre-configured Windows PC loaded with QCAD, Inkscape, SheetCAM and Mach3; check each kit listing for exactly what is included. MyPlasm kits use the MyPlasm CNC software with its built-in MyMiniCAM module.
Can I build my own CNC plasma table with your parts?
Yes. Our DIY build kits and individual parts give you a matched set of controller, drivers, motors and wiring. Add a block of tech support hours and we will help you from first power-up to first cut.
Do your control systems work on CNC routers?
Many components, such as controllers, stepper motors and drivers, are shared between plasma and router machines, and Mach3 runs both. Contact us for a router configuration.
Mach3, SheetCAM, QCAD and Inkscape
Which SheetCAM post processor should I use with Mach3?
Start with the basic Mach3 plasma post to confirm the table cuts correctly, then move to a THC post such as Mach3 THC with scriber and set its options, like the switch offset for a floating head and your pierce and cut heights. The right post depends on your torch height control and touch-off method; we can set it up with you in a support session.
Why does my torch dive into the material when THC is on in Mach3?
The usual causes are the wrong target arc voltage, THC up and down signals wired in reverse, or the Z axis losing steps because the THC rate is set too high. Test with THC off first, then use the Mach3 diagnostics screen to confirm the up and down inputs respond as the torch moves.
Why doesn't my Z height in Mach3 match the real torch height?
Either the Z axis is losing position, usually from stalling under too much speed or acceleration, or the steps per unit are wrong. Lower the THC rate and Z acceleration, check couplers and pulleys for slip, and verify the Z calibration.
QCAD or Inkscape: which should I use for plasma designs?
QCAD is 2D CAD software suited to precise parts with exact dimensions, like brackets and plates. Inkscape is a vector drawing program suited to signs, artwork and tracing images. Both export files that SheetCAM turns into cut paths.
How do I calibrate my table so parts come out the right size?
Command a known move, such as 24 inches, on each axis, measure the actual travel and adjust the steps per unit to match. If the size still drifts, look for mechanical slop: loose pulleys, worn bearings, belt or rack slip.
Can I use SheetCAM with MyPlasm?
MyPlasm includes MyMiniCAM, which handles most jobs, and it can import G-code. To use SheetCAM you need a post processor that formats the code for MyPlasm. We can help configure it.
MyPlasm, MyPlasm Pro and Proma torch height control
Do you support MyPlasm and MyPlasm Pro systems?
Yes. We set up, configure, troubleshoot and repair MyPlasm and MyPlasm Pro systems, and we can upgrade older controllers to either one.
What does an Arc OK error mean in MyPlasm?
The controller did not get the Arc OK (arc transfer) signal from your plasma cutter. Check the Arc OK wiring at the cutter's CNC interface port, look for loose connections, replace worn consumables and make sure your cut height is not set too low.
My axis won't stop at the home switch. What's wrong?
Test the switch itself, check its wiring and make sure it is connected to the correct input for that axis. On dual-motor gantries, each side's switch has to be on its own assigned input.
What is a Proma torch height controller, and do I need one?
A torch height controller (THC) reads arc voltage during the cut and moves the Z axis to keep the torch at a constant distance from warped or uneven plate. A Proma THC 150 is a standalone unit often paired with Mach3; MyPlasm has THC built in. For consistent cut quality, THC is strongly recommended.
How do I set up a Proma THC with Mach3?
Wire the THC up, down and Arc OK signals to your breakout board, connect a voltage divider at the plasma cutter, set the target voltage and configure the Mach3 THC settings. Get the table cutting cleanly with THC off before turning it on. A setup session is the fastest way through it.
Troubleshooting
Mach3 shows External E-Stop or a limit trips when the torch fires. Why?
That is almost always electrical noise from the plasma arc. Ground the table to a dedicated ground rod with heavy cable, keep signal cables away from torch leads, use shielded cable grounded at one end and use optically isolated inputs for switches.
The torch fires but the table won't move. What should I check?
The controller is likely waiting for the Arc OK signal. Check the Arc OK wiring and settings, look for noise problems and replace worn consumables.
My torch won't sense the plate, or presses down too hard. Why?
Slag trapped between the nozzle and shield can short the ohmic sensor, so clean the consumables first. Then check the ohmic wire, the floating head switch and the switch offset in your post processor or controller.
Why is my cut quality poor, with bevel, dross or bad holes?
Match your speed, amperage and cut height to your plasma cutter's cut charts, use fresh consumables and check cut direction. Small holes need their own slower settings.
How do I know if the problem is electronics or mechanics?
Run the job with the torch off. If motion is smooth and accurate, the problem is likely torch, THC or noise related. If it still misbehaves, look at the mechanics or motion settings. A diagnostic session can narrow it down quickly.
Buying a plasma cutter or table
What should I look for in a plasma cutter for a CNC table?
Look for a CNC interface port for remote torch on and off and Arc OK, a divided arc voltage output for torch height control, a machine torch or CNC-capable hand torch, enough amperage for your thickest material and easy-to-find consumables. We work with Hypertherm, Everlast and PrimeWeld cutters.
Buying a used CNC plasma table: what should I check?
Check that the frame and gantry are square and rigid; the rails, bearings, belts or rack for wear; the condition of the slats or water table; whether the software licenses transfer; and whether parts are still available. Ask the seller for a video of a test cut. We can review the listing and photos with you before you buy, billed as standard consult time.
Can you inspect, test and appraise a used CNC plasma machine before I buy it?
Yes, for the standard consult fee, starting at $120/hr. We walk through the machine with you, live by phone or video while you are with the seller, or from the listing photos and videos. We cover what to look for and what to test, including the frame and gantry, motion on every axis, torch height control, the plasma cutter and a test cut.
Then we estimate a fair value based on its current condition, list what it may need right away and point out which upgrades are worth making later, so you know the real cost before you hand over any money.
Can you help me choose a new or used plasma cutter or table?
Yes. Consulting is billed like tech support, and hour blocks lower the rate. We will talk through what you plan to cut, your space and budget, and recommend a plasma cutter, table size and control system that fit.
Should I retrofit my old table or buy a new one?
If the frame and gantry are solid, a retrofit usually costs much less than a new table of the same size. If the frame is worn out, new may make more sense. A diagnostic session gives you a straight answer.
Tech support, consulting and local service
How much does tech support and consulting cost?
Standard support, Monday to Friday, 9am to 5pm Pacific, is $120/hr. Buy more hours and save $5/hr for every hour you add, down to $100/hr: 2 hours for $230, 3 hours for $330, 4 hours for $420, 5 hours for $500 or 10 hours for $1,000. After hours or emergency support is $180/hr.
Buy your hours online and we contact you within 1 business day to schedule a phone or video call. Hours are non-refundable and valid for 6 months from the date of purchase.
Do I have to use my block hours all at once? Do they expire?
You don't have to use them all at once. Your tech and consulting time is tracked as you use it, so you can spread a block across several calls, such as setup, tuning, troubleshooting or a used-machine appraisal.
Hours are valid for 6 months from the date of purchase, and any unused hours expire after that. Tech support and consulting hours are non-refundable.
Do you do on-site retrofits?
CNC X WRIGHT takes on select on-site retrofits in the Las Vegas area only. Everywhere else, we ship kits and parts and support you remotely by phone or video.
Can you help with a table you didn't sell me?
Yes. Paid tech support covers most entry-level to mid-range CNC plasma tables, including Wright CNC, Wright-style tables and other brands.
What should I have ready before a support session?
Your controller and software (Mach3, MyPlasm and so on), your plasma cutter make and model, photos of your control box wiring and a short description of the problem.
Orders, shipping and repair parts
How long does shipping take?
In-stock items ship within a few business days. Build-to-order kits typically ship in 2 to 3 weeks, and you will get your estimated ship date by email.
How do special orders work?
Custom builds start with a $250 non-refundable deposit. The balance is due when your order is ready to ship.
Do you sell repair parts for older plasma tables?
Yes: stepper motors, drivers, torch height controllers, switches, cables and more. If you don't see the part you need in CNC Parts, contact us and we will help you find it.