CNC plasma cutter options

**routercnc** · 02-07-2024

Hi,
I'm not fully committed to this, just looking into it for now, but does anyone know of a low cost plasma cutting machine suitable to use with a CNC machine. I think HF start is too risky - although I did think about running the control system, steppers, monitor, NUC PC all off DC power (e.g. 36V LiPo battery) and enclosed in a metal cabinet, installing the steppers on plastic/3D printed mounts and couplers to ensure no electrical connection to the machine. But it would be a gamble I think.

I'm looking for the low frequency blow back style, not the high frequency pilot arc, otherwise I think the CNC control system will have issues even with my best attempts at shielding and grounding.

I think the hypertherm and other high end models will probably blow the budget. I've seen models like the HeroCut CUT55X blow back machine with CNC connections (for arc voltage, and torch control) at £288.25 + £128.63 delivery [in September!] on AliExpress. Not sure about that one.

I've also seen the Hynade CNC CUT60DN blow back machine but it was only available on the US Amazon Website ($499.99), not the UK one. If it had been on the UK Amazon site I guess it would have been around £500 (they tend not to price them as per the exchange rate!) and this would have been tempting.

Has anyone seen anything in this sort of price range with blow back LF start and THC/torch start output connectors?

Thanks

**routercnc** · 11-08-2024

OK, I finally found a well priced and well featured plasma cutter. Here we go again on another CNC project!

**Desertboy** · 12-08-2024

Check Rtech out

I had one and I remember it had a port for cnc related functions

So I assume it must be compatible

Was about 600 quid

I sold it for 400 in the end because It didn't cut what we wanted, we were scrapping

We weren't CNC

Oxy is kind of bullet proof

**routercnc** · 12-08-2024

Originally Posted by Desertboy

Check Rtech out

I had one and I remember it had a port for cnc related functions

So I assume it must be compatible

Was about 600 quid

I sold it for 400 in the end because It didn't cut what we wanted, we were scrapping

We weren't CNC

Oxy is kind of bullet proof

Thanks, I did look at RTech but the CNC blow back style ones were over £1000. The high frequency ones were around £600 but I don't want to use that for CNC due to interference.

**Muzzer** · 12-08-2024

That connector is actually a German "Schuko" Type F plug which is rated at 16A - it's not a US plug as you believe you were told.

Our UK plugs are massively overdesigned and won't break a sweat at 13A or even 16A if you buy a decent brand and of course the ring main behind the socket will be fine supplying 30A. However, your plasma cutter will only have a limited duty cycle anyway and even that will be specified at full power. Bottom line, Just put a decent quality 13A plug on it and be done. The fuse won't blow unless you subject it to over 30A continuous.

Those airline fittings are almost certainly "Euro" (aka XF) style ones, like you get on Lidl gear - I have quite a few of them in my workshop as a result. I swapped some of them for the more normal "UK Standard Adaptor" (aka PCL) fittings found on our air tools but the thread at the rear was the same, presumably 1/4" BSP or similar. You could probably just unscrew the XF and replace with a PCL.

I'm pretty certain you've got a German spec machine there....

AliExpress is offering me this for £265 all in, inc delivery to the UK. Only one left currently but I'm not looking to buy.

**routercnc** · 12-08-2024

Hi Muzzer.

Sorry I didn't explain it that well in the video. They sent me a US spec machine (they were sold out of EU and AU style), but they did not include the adapter plug which goes from EU (German Type F) to US style plug since they knew I was based in the UK. This is a separate part they throw in the box for US customers as the plasma has an EU plug as standard build.

But I do believe the airline male is type 23 (Rectus) and is maybe more common in the US? My workshop has Euro fittings and they do not fit the plasma male fitting. My understanding is the 'PCL fittings' are the most popular in the UK closely followed by Euro, but a fitting which I believed to be PCL also did not fit the plasma. The industrial shop I went to sold me a fitting marked Type 23 made by Rectus to connect to the plasma so that must be it.

The other end of the plasma fitting (into the air filter inside the machine) is listed at 1/4 NPT in the manual, which is US spec (so not 1/4" BSP unfortunately). All told I think you are right though and I could have unscrewed the male fitting and replaced it with a 1/4 NPT to Euro male, if that exists, not checked . . .

On the electrical front I've just called an electrical company today we use for a quote on the 32A commando, where I would do all the cable prep work, dig a trench (it has to come from the other side of the house) etc. and they would do the connections and checks. But our solar panel system complicates things and the CU is full, so it needs yet another mini CU outside the house (there are 2 there already). I'm thinking it is going to cost more than the plasma! So, thinking about your comments; the double sockets are MK metal clad, so quality units. The garage has quite a few doubles on a dedicated ring from the CU (at 2.5mm2) but it all runs off a 20A breaker in the CU. Perhaps I could ask him if he would agree to fit a 32A breaker in the CU and confirm he can see 2.5mm2 cable on that circuit (as he did not install it). The plasma is 60% duty cycle, and I expect to cut thin sheets, but my plan is to cut at max power and cut quickly. This means 50A out of the plasma and ~30A from the socket. Everywhere I look the 2.5mm2 is ~15A or so on a 15A-20A breaker. I'll sleep on it as I don't want a fire!

£265 delivered is a great price though!

**routercnc** · 07-09-2024

OK here is the next installment. I designed the Z axis to have up and down, touch off sensing, and torch breakaway. But I didn't like how it turned out . . .