Plasma Digital Torch Height Controller

A microprocessor controlled DTHC specifically designed to work exclusively with selected models from the Hypertherm Powermax range of plasma cutters and where your table is controlled by Mach3.

Special Note: I'm getting early reports from a user that this THC works well with his Thermal Dynamics plasma cutter. If I can get confirmed detail of this then I will add it to the range of supported cutters.

Please read carefully to see if this THC is suitable for your system.

Other aftermarket THC systems need either interface electronics or the whole system to be installed inside the plasma cutter power supply. However, most Hypertherm models come with an interface already built in as standard. (Hypertherm refer to this variously as the robotics interface, the mechanized cutting interface or the machine interface). This THC is exclusively designed to connect to that existing interface so you don't need to install anything inside the plasma cutter power supply case. If you have one of these Hypertherm models then this THC is the one for you.

So which models are supported?

The current models of the Powermax45, Powermax1000, 1250 and 1650 have the interface as standard with a plug brought out on the rear panel. However, note that there are some early models of the Powermax1000, 1250 and 1650 that were not equipped with the divided (50:1) output. These earlier units would not have connections on pins 5 and 6 of the interface connector. I am told there is a Hypertherm upgrade part for this (Hypertherm part# 123892) but you should contact your Hypertherm dealer to confirm that yours can be upgraded.

The newer Powermax65 and 85 are shipped with the interface as an option. If yours doesn't have it you can upgrade with the addition of Hypertherm part# 228696.

I have absolutely no affiliation with Hypertherm so there may be other plasma cutter models or options that they sell that have a similar interface. If in any doubt I suggest you contact your dealer and check whether your system has the same robotics interface as the Powermax45.

Whichever model you intend to use with this THC you will need a machine interface cable available from your Hypertherm distributor (part# 123896).

The above plasma systems all come with the option of having a hand held torch or a machine torch. To use this THC you MUST have the machine torch. This is because for safety reasons, Hypertherm disable their robotics interface when the hand torch is connected. Also, in general most hand torch system configurations don't have the interface, whilst most machine torch configurations do.

What else is needed in order to use this THC?

  • A Machine Interface Cable with a D-sub Connector that includes the wires for the Voltage Divider Signal. If you don't already have one of these then they can be purchased from your local Hypertherm dealer. (Ask for part# 123896)
  • A CNC table controlled by a licenced[1] Mach3 (VR3.043.022 or later) via the parallel port or one of the external motion control cards that FULLY support THC functionality.[2]
  • Some method of performing Initial Height Sensing (IHS). Floating head and/or Ohmic sensing are two popular methods. You should be doing this anyway even if you don't yet use a THC.
  • 1 spare SERIAL (RS232) port on your PC or USB with a USB to RS232 Converter Cable.
  • 1 spare output pin on your parallel port/BOB.
  • 3 spare input pins on your parallel port/BOB.
  • Note that you don't need a second parallel port to use this THC.
  • A REGULATED 5Vdc supply - what you use for the logic supply of your motor drivers is fine.

[1] Mach3's internal THC functionality is crippled in demo mode.

[2] A user has reported that the CSMIO fully supports THC and that this THC works very well with it. However at the moment you will have to supply the interface between the 5V signalling of the THC and the 24V signalling of the CSMIO. If this proves a popular option then it is my intention to add in the level shifting to the next release of the THC. I am also told that the Ethernet SmoothStepper fully supports THC but as yet I have been unable to confirm this with the makers of the ESS.

What do I get if I buy the THC?

  • The THC card itself of course, which measures approx. 100mm x 90mm (4" x 3.5").
  • A 1.8 Metre DB9 male to female RS232 Serial Extension Cable.
  • A custom Mach3 plasma Screenset with associated setup and control files.
  • Comprehensive and easy to follow hardware and software installation instructions.


Digital Torch Height Controller

Mach3 Screenset

Custom Mach3 THC Screenset

How do I operate the THC?

  • Set the required voltage for your job. You can do this either in the Mach3 screen DRO, set it in gcode with the S word or use the "Sample & Hold" feature.
  • Switch on Mach3's THC control via the on-screen button.
  • Optionally, switch on Mach3's anti-dive control via the on-screen button.
  • Run your job.
  • If neccessary, you can fine adjust the required arc voltage on-screen in real time whilst your job is running.
  • The actual arc voltage is displayed real-time throughout the cutting process. This makes tweaking your optimum arc voltage and hence your optimum torch to work height a snip.
  • Once you've tweaked your system you can pretty much enter your required voltage or even better put it in your g-code and forget it, the THC will keep your optimum cut height without further intervention. No knobs to twiddle or madly flickering LCD displays to try to chase.

The Razordance Digital Torch Height Controller costs £190 (GBP). This price includes FREE shipping worldwide.

Shipping normally takes from 1 to 3 working days. However some countries seem to have slower than average customs clearance so depending on your location it may take a few days longer.

Razordance working hours are 09:00 to 17:00 GMT Monday to Friday. Orders placed at the weekend will be shipped on Monday.

Please note:

  • Any local import taxes or duties are your responsibility to pay.
  • The item must be signed for on delivery.
  • Please read the Terms & Conditions of Sale before you buy. (If you don't have a PDF reader I suggest Foxit PDF reader)

Payment is via PayPal. If you don't have a PayPal account you can pay with your debit or credit card as a PayPal guest. Just click Buy Now and follow the instructions.


All material © Copyright 2007-2013 Razordance

The right is reserved to alter any information on this web site without notice.

Errors and omissions exempt

Please report any website issues to the Webmaster


Product names used herein are for identification purposes only and may be trademarks of their respective owners.

Razordance disclaims any and all rights in those marks.

Valid XHTML 1.0 Transitional Valid CSS!