CNC Plasma Cutter

CNC Plasma Cutter
Name	Retina Ripper 9000
Zone	Welding Area
Reservation Address	Link
Reservation Calendar URL	Link
	HOWTO Reserve Time on Equipment
Owner	i3Detroit
Make Model	Langmuir Crossfire Pro
Part Number	4'x3'
Date Acquired	2/9/25
Storage Location	Welding Zone
Authorization Required	Yes
Status	Down
Value	3000
Documentation	https://www.langmuirsystems.com/pro https://store.langmuirsystems.com/products/razorweld-razorcut-45-with-machine-torch https://www.langmuirsystems.com/software https://www.langmuirsystems.com/software/fusion https://www.langmuirsystems.com/firecontrol/guide https://arclightcnc.com/wp-content/uploads/2022/09/Plasma-Green-9010-Green-Guard-SDS.pdf
Other References

Intro

Langmuir Crossfire Pro bought used from a sign shop over on John R. 

This machine has a machine torch, automatic torch height control and a water table for production work.

This machine should be continuously monitored while in use -- it can generate fumes, do damage to eyes and cause fires with little notice.

Learning Resources

• SheetCam: This is the software where you will build your GCode file to run the machine and set most of your settings for your cuts.
  • It is highly recommended that you watch AT LEAST "SheetCam Tutorial 1 Basics" and "Sheetcam Tutuorial 4: Moving Parts and Basic Nesting" from This YouTube Playlist but all of the videos in this playlist are super helpful to learning the ins and outs of SheetCam as it is the most important software to know for the CNC Plasma.

• FireControl: This is the software that takes your gcode and actually runs the machine. Please watch both of the following videos.
  • Intro to FireControl
  • FireControl Manipulations

Rules

• Authorization is required to use the CNC Plasma Cutter
• Use proper safety measures (i.e. Proper Eye Protection) at all times when the plasma is running.
• Never leave the machine unattended while running.
• Make sure to either "close the door" to the Welding Zone with the shield or use the red shield curtain on the machine when in use as to not blind anyone who is in or might walk into the zone.
• Never use the machine while under the influence of drugs, alcohol, or any other intoxicant.
• Never reach into the machine while it's running.
• This machine throws lots of sparks. If you're going to stand in front of it and watch without the curtain, don't wear synthetic clothing.
• The metal will be HOT! when the cut is finished. Please use proper safety precautions when handling (hot gloves, pliers, etc).
• Before discarding any metal from the plasma, please quench it in water to cool before adding to scrap bin or trash can.

Instructions

Start Up Procedure

• Hook up the air line drop that's attached to the 220v line to the air filter system on the back left side of the machine wall. Ensure the air compressor is on and the regulator on the filter system is set to ~70psi.

• Plug in the surge protector strip and turn on the individual switches on the strip.
• Before powering on the Plasma Cutter, make sure it is set to 45A (knob all the way to the right).

• Turn on Plasma Cutter switch on back of machine (Plug in to 220v outlet hanging above if unplugged first) 

• Check Water Table Level. Water level should be just above the bottoms of the knife edge rails. If lower, add water until it reaches this level.

• Make sure the ground clamp/magnet is attached to the machine (front face or underside of the water table will work best)

SheetCam Instructions

SheetCam accepts multiple vector format file types with .dxf files being the most common. Design your object in any 2D (Inkscape, Illustrator, etc) or CAD software (Fusion360, OnShape, etc) and export your file as .dxf or .svf and set your unit of measurement/scale to inches.

1. Import Design File

1. Open SheetCam and select File > Import Drawing.
   1. A dialog box will appear regarding scaling. Make sure 1:1 scaling in inches is selected.

2: Create Cutting Operations

1. Creating the Operation
   1. From the top navigation menu, select Operation then choose Plasma Cut from the list.
   2. Once the settings window opens, select the layer from the drop-down menu you wish to apply settings to.
2. Setting Offsets (Inside/Outside):
   1. For compound shapes, choosing Outside Offset will cut from the outside of your outer shapes and from inside of your inner shapes.
   2. Outside Offsets (Contour): For external shapes, select Outside Offset under the Offset section. This tells the machine to cut just outside the line, preserving the dimensions of the final piece.
   3. Inside Offsets (Holes/Cutouts): For internal cutouts (like holes or internal slots), select Inside Offset. This tells the machine to cut just inside the line, preserving the dimensions of the hole.
   4. No Offset: Occasionally used for etching or marking where the center of the plasma stream follows the line exactly.
3. Tool Selections
   1. There are some preloaded tool settings in SheetCam. These will get you close but feel free to experiment. The main thing here is to choose the material and thickness that closest matches yours.
   2. Once you've chosen a tool, a feed speed setting will appear in the box below. Feel free to change this setting to speed up or slow down your cuts if desired.
4. Lead-In / Lead-Out Selections:
   1. The lead-in and lead-out determine how the torch starts and stops the cut to avoid starting on the final line and leaving a gouge.
   2. Type: The most common is Perpendicular (a straight line lead-in) or Arc (a curved lead-in). Arc is often preferred for smoother starts.
   3. Length: Set a length (.5" is usually good here). This is the length of the approach path before the torch reaches the main cutting line.
   4. Kerf Compensation: (Advanced Users Only) Ensure the correct Kerf (cut width) for your 45A plasma is set in your Tool definition, as SheetCam uses this for accurate offsetting.
   5. Click OK to create the operation. Review the cut path (indicated by colored lines) to ensure it looks correct.

Repeat any steps as necessary for any other layers you have in your file.

3. Export G-code File

1. In the main navigation menu go to File > Run Postprocessor and save your file with the .tap file extension (which it should be default).

FireControl and Cutting Instructions

1. Load the G-code File
   1. Open FireControl
   2. Click the green Load File button near the top left of the screen where it says “Load Program”
   3. Navigate to and select the .tap file you just exported from SheetCam.
2. Prepare the Program for Running
   1. Click “Set Program Origin” from the left hand menu and choose where you would like your cut to start in relation to your design. Click any of the green boxes to select any corner or the center as your origin.
   2. With your material on the table, use the X, Y and Z controls in the bottom right corner to move the plasma head where you would like it to start above your piece.
      1. You can change the speed the head moves by changing the Job Speed selector on the right side of the screen.
      2. This machine has an auto Z-Height feature and will automatically check the height every time it makes a cut. As a general rule of thumb, do not put the plasma head any closer than 1/2" from your work piece when using the Z-Height controls for the safety of the plasma head. You only need to set your X and Y positions before cutting.
   3. Once the plasma head is in the position you want it to start from, click the “Zero All Axes” button below the Coordinates Grid near the top right of your screen. You should see the white X and Y Axis lines move on your cut preview screen to the program origin you set.
   4. To confirm you’ve done everything correctly, click the blue “Go To Work Zero” button from the left-side menu. If the head doesn’t move, you’re ready to cut.
3. Dry Run (Optional but Recommended):
   1. Select the Dry Run toggle button and make sure it’s toggled on!
   2. Make sure the plasma head Z axis is off the piece by about ¼” or more to prevent it from knocking into any bows you might have in the metal.
   3. Click Start Program.
   4. The machine will run through the entire G-code path, but the Z-axis will remain up, and the plasma torch will not fire. This lets you visually check for path collisions, ensure the design fits the material, and confirm all motions are correct.
   5. Click Stop or let the dry run finish.
   6. Important: Remember to uncheck the Dry Run box before running the actual program!
4. Run the Program
   1. Ensure Safe Setup:
      1. The origin point is properly set. Select “Go To Work Zero” to make sure the head is starting where you want it to.
      2. Make sure the starting point on your material is supported by slats on both sides.
      3. Make sure the water table is filled to the proper level (roughly the bottom ¼” of the slats are submerged)
      4. Air is on and connected and the pressure is correct (70psi)
      5. The plasma cutter itself is turned on at the back of the machine.
      6. Ground clamp is securely attached to the plasma chassis or work table.
      7. Dry Run is OFF.
   2. Click the Start Program button.
   3. The machine will execute the G-code, firing the torch and cutting your design. Monitor the machine closely during the entire process.

Shut Down Procedure

• Park head at back left of machine in case anyone wants to use plasma table for manual cutting. Please do this slowly for now (either lower the head speed or nudge it as it gets close) until limit switches are installed.
• Turn off all of the switches on the power strip then unplug the power strip.
• Turn off the plasma cutter by toggling the switch to 0 on the back of the machine.
• Disconnect the air line from the air filters.
• Do your best to knock off any slag from the rails (Use a hammer and a crappy chisel)
• Remove all of your metal from the bed and do your best to remove cutout pieces that have fallen into the water table. *The liquid additive to the table is non-toxic but still recommend you don't just stick your hands in. Use gloves or pliers to remove objects from the water table.

Maintenance Info

Most of the maintenance is related to the CNC part -- cleaning and greasing the leadscrews, cleaning the bearings on the box tube, etc. The rest is consumable materials on the plasma cutter itself. Beyond that, the water needs to be checked for appropriate bacteria/algae resistance and replaced every so often.

HOWTO: Change Plasma Table Liquid

(In Progress)

Table Liquid Change Log

• 10/21/2025 (Alex Zurowski and Will Cunningham)

HOWTO: Clean Air Filters

(In Progress)

HOWTO: How and When to Change Out Plasma Consumables

If you're noticing excessive dross or beveling, reduced cut quality, or any other cut quality issues, it may be time to replace one or more of the consumables.

Some of these consumables (mainly the nozzle and electrode) require changing every 1-3 cutting hours if you want to maintain high cut quality. The machine will still cut without changes of these parts at that interval, though cut quality will suffer.

For information on when and how to change consumables please watch this video

FAQ

-Water Table currently using 20:1 Concentration of Plasma Green 9010.

What is the cost to use the machine?

There is a suggested donation amount of $3 per quarter hour of machine run time as the machine requires about $15 in consumables every 2-3 hours of run time (see the section above on plasma consumables). This can be paid to the cash box in the welding zone located on the table in the back left of the zone or via PayPal.

What Can the CNC Plasma Cut?

A plasma cutter can cut any electrically conductive metal, including mild steel, stainless steel, aluminum, copper, and brass.

What can the CNC Plasma Not Cut?

It cannot cut non-conductive materials like wood, glass, ceramic, plastic, or bananas. You heard me right. Bananas!

What Thickness of Material can it cut?

It can typically clean cut up to 1/2" of mild steel. We have not tested other materials or thicknesses of mild steel but 1/2" is about standard for our 45amp machine.

ToDo

1. Install permanent air drop for the machine, check air humidity/oil/etc. (Complete)
2. Install permanent power for the CNC side of the machine
3. Clean out the water table (Complete 10/21/25. Alex Zurowski and Will Cunningham)
4. Seal water table leaks (Complete 10/17/25. Alex Zurowski and Will Cunningham)
5. Install limit switches (included with purchase, not currently installed)
6. Develop class content for training (In Progress)
7. Inventory consumables for the plasma cutter (Complete 10/21/25. Alex Zurowski and Will Cunningham)
8. Determine per-minute rate for using the machine (Complete: $3/Quarter Hour)
9. Put together instructions on swapping to the hand torch on the plasma cutter for hand work
10. Create signs for Down/Training/Etc
11. Email Plasma Green about water evaporation and refilling. (Complete 10/22 Will Cunningham)

Authorized Users and Trainers

Trainer Name	Certified Date
Alex Zurowski	2/9/25
Zach Sutton	2/9/25

User Name	Authorized By	Date of Most Recent Training
Zach Sutton	Zach Sutton	2/9/25
Alex Zurowski	Alex Zurowski	2/9/25

Spare Parts Inventory

Part Number	Part Name	Quantity	Last Updated
RW60305T	HYP Retaining Cap, CUT45	1	10/24/2025
RW51206	HYP Cutting Nozzle Cut 45	5	10/24/2025
RW52574	HYP Cutting Electrode CUT45	5	10/24/2025
RW60041	HYP Swirl Ring CUT45	1	10/24/2025
220669	Razorweld Cutting Electrodes 45A	9	10/24/2025
220671	Razorweld Cutting Tips 45A	9	10/24/2025
None	Knife Edge Rails (Full Set)	1	10/24/2025
None	Unlabeled Electrode and Tip	1	10/24/2025