You need a pretty sizeable air compressor – 3hp / 100 litre sort of scale – cutting 10mm steel requires a pretty slow feed rate so you’ll be get through an awful lot of air on each cut. To prevent ruining a lot of cutting consumables too quickly (like one set every cut) you need decent quality air-drying equipment too – bog standard air filters from machine mart don’t cut it- And you need a meaty power supply – my cutter has has to be wired into a 40amp supply and thats running in addition to the draw for the compressor, so really both those machines need to be on different phases / circuits. You also need the right kind of breaker fitted otherwise the surge when you strike the arc will trip it anyway.
Mines a Hypertherm Powermax 45. Cost about £2k which I bought to use for CNC work – Some of that cost is internal electronics for hooking up to the CNC equipment though. The original £100 odd quid air dryer I bought (hypertherm’s own product) didn’t cut the mustard with a compressor running in wet and windy west scotland but a much larger £300 one is cutting down the expense of replacing tips and nozzles. I now run both dryers in series and that set up still isn’t as good as it should be. The compressor was about £450.
That set up can pierce at 10mm, and cut at about 1 foot per minute – anything thicker – upto 16mm it can only cut from an edge rather than in the middle of a plate.
Whatever cutter you buy factor in that the respective consumables need to be obtainable easily too and check what they cost – the tips and nozzles for mine can cost about a tenner each unless I buy them in bulk – and they have to be replaced in pairs – so £20 per tip change. And don’t forget you’re basically short circuiting the national grid while you’re cutting – so electricity bills are quite juicy too.
The fume from plasma cutting is properly horrible – I work over a water table to keep the filth under control but without that then you’re creating clouds of atomised steel that you definitely don’t want to breath and its going to coat everything else in the room.
