Lotos LTP5500D CNC Cut Chart

Hi All, I’ve finally gotten my CrossFire table operational and have come up with the cut chart for the LTD5500D CNC plasma cutter I’m using. Since I’m new to this forum, I’ll try to upload the cutchart here, but if that doesn’t work, the cut chart and related info is at https://github.com/TomWS1/CrossFire
To determine cutting parameters, I used G-Code scripts modified from those contributed by @Mike_C in Test cut program to find the ideal cutting speed and have placed those files in the repository as well.

For what it’s worth, the cutter, delivered, was $529 on Amazon (uwelding lists at same price, but I don’t know if they have free shipping). Make sure you specify the CNC version as the other version don’t have the right connectors on the back. It took all of 5 minutes to set it up as the cutter includes the CNC connector needed to control it from the CrossFire controller and I’ve had no issues with noise.
Lotos LTD5500D CNC Crossfire Cut Chart.ods.dxf (600.1 KB)


I just bought the same plasma and would like to see if you would share some pictures or schematic on how you connected CONTROL SIGNAL (on/ off), VOLTAGE OUTPUT and CONTROL SIGNAL (left and right).


Here is the sheet, documenting the CNC connectors on the back panel, that came with the CNC version of the LTP5500D. As you can see, the Start (CONTROL SIGNAL) is connected to pins 1 & 2 of the 4 pin connector. These two pins connect to the free end of the CrossFire torch control cable - the order isn’t important - it’s just a switch contact.

The Voltage output, which I don’t use yet as I don’t have THC yet, is on the separate 2 pin connector. NOTE: this voltage is a 1:1 divider so is FULL voltage and would need a divider board to process it.

My unit came with the mating connectors, so it was easy to hook up.

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Thank you for the reply. To use the THC, i would need a THC controller module, correct?

To use THC on a CrossFire (not Pro), you’ll need more than that. You’ll need to add Z Axis track and motor, Z Axis driver, some SW changes to your configs, and, yes, a THC controller. See @Dicky’s thread to see what’s involved. (THC Installation Step by Step)

Thank you.

Hi tomws how can i contact you for some question about lotos ltd5500D ?

Since you’re new to the forum and aren’t allowed to send personal messages, using posts is the only option. So, what do you want to know?

Thanks for respond
Do you are using lotos LTP5500D in your langmuir?
I recently bought a crossfire and I have no idea if it works or not because this plasma is blowback start as they recommend on the langmuir page .but they also have a message that says they do not recommend it but I think that the one they do not recommend is the old machine what is hf.

Yes, it works well with no interference.

The information on the CrossFire compatibility page is incorrect and probably relates to an earlier version (LTP5000) as you suggest. The LTP5500D is specifically made for CNC systems and @langmuirsystems should update their compatibility information.

Perhaps if @langmuirsystems took a forum poll on what plasma cutters people are using at this point they would be able to easily update their list.


Thank you very much for the information I am new to this and it is the plama that I would like to use since I have it for a year and it is very good for the value it has and the quality anyway I would like to be in contact with you here my email by If you can send me more information I will be thanking you very much
Macho-ag@hotmail.com thanks, thanks

Hi Tom, How’s your LTP5500D going? Did you change a new one?

The LTP5500D is still going strong (at least well enough :wink:
I haven’t had a bit of problem with it. It’s certainly not a ‘professional’ cutter, but it works for me. With material, I figure if I can’t lift it, I have no business trying to cut it!

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Hi Tom, Really appreciate your sharing!
I am wondering how thick it can(mild steel) cut with LS table?

I haven’t cut anything thick with it, probably the thickest was 1/4". It can probably cut through 1/2" of steel in the right circumstances, but I wouldn’t expect to cut a pattern in anything more than 3/8. Maybe I’m shortchanging it, but I wouldn’t make any claims on anything I haven’t tried.

Thanks Tom,
Once I get the cutter I will try to figure it out. Maybe I will need your help then.

Hey Tom,
Im running the same machine as well and was curious if you are running the recommended settings and what consumables you are using. I have personally had to reduce feed rates down to 70 - 50 percent depending on the material when I didnt have to before.

‘Before’ what? What did you use ‘before’?

Here are my current SheetCam tools settings.
Default.zip (1.2 KB)

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I am trying to run the Lotos LTP5500D with my crossfire pro and not having any luck. Customer support says it is not compatible. I am curious what settings you use or how you get this to work with your Langmuir?



I’ve been using the Lotos LTP5500D -CNC for the last 2.5 years. The LTP5000 is NOT compatible, the LTP5500D (if it’s the CNC version) is. I use the CNC port for Torch control and second connector for THC sensing.

UPDATE: Apparently there is a difference between the LTP5500D and the LTP5500D-CNC. The CNC version has external connectors on the back panel for a CNC hookup, the LTP5500D does not. HOWEVER, the LTP5500D IS blowback start so will be compatible, but you’ll have to hardwire in Torch On/Off Control and THC voltage (it you use THC).

Both of these sets of signals can be readily found on the Torch connector.