Plasma cutting,first attempt

[Superbad]

Not very good,just molten metal on 10mm thick mild steel,using my recent purchase
http://www.pcsimports.com.au/products/2-mitech-50-amp-plasma-cutter.aspx
I don't have single phase sockets in my unit,so I've bought one of these
http://www.ebay.co.uk/itm/UK-13amp-...4261?pt=UK_Cables_Hookups&hash=item3a70142f95
Keeps blowing fuses.
suggestions most welcome

 

[Shox Dr]

Well for a start you are wandering all over the place, so that will not help. and because your leccy is tripping I'd say you are not getting enough power either

 

[astro_al]

Oof!

To test it out, only cut in straight lines. Use a guide and try various thicknesses of steel at various amp settings and various travel speeds. Be methodical and you'll find the good combination. You should have travel speed and machine setting info in your manual.

Other than that, keep an eye on consumable condition, with cuts like that, they won't last long, and try not to use wet air.

Al

 

[rtbcomp]

From the spec sheet

"Rented input power (KVA) 6.5"

That's about twice the rating of a 13 Amp plug. Looks like you need a 32 Amp single phase circuit installing.

Moving the torch too quickly is one cause of gouging rather than cutting.

 

[gordon stephenson]

Start off on some thinner plate, 3mm.And as already suggested cut straight lines using a staight edge as a guide,Does the manual recommend dragging the torch on the metal or use a small stand off, And yes, Dry air is a must for good results and long consumable life.

 

[frd906]

Have you got the right air pressure set up

 

[astro_al]

Also, get some appropriate eyewear (NOT sunglasses!!!) and, just like welding, try to watch the arc / cut taking place - like watching the weld pool. You should be able to see it cutting nicely at some speed, and adjust your travel rate accordingly. The direction of the sparks flying out the bottom also indicate how correct your feed rate is. You're definitely going too fast on that plate.

Try to actually monitor how its going during the cut, rather than swiping the torch across the metal and hoping it comes out ok.

Al.

 

[Drains]

Have you got the earth lead attached? A plasma will just about manage to gouge (or even cut very thin sheet) without the earth lead on, but it'll ruin the consumables.

If that's not the problem - then you're making the mistake of not getting the cut started but banging on regardless. As Al says - you need to get those sparks coming out from underneath the metal, and keeping it that way. The trick with plasma is to get the speed exactly right - not too fast, not too slow.


BTW, I like this quote from the spec sheet

"If you are having trouble comparing this machine to others being sold their is no comparison. This Mitech Plasma Cutter is the top of the line"​

 

[astro_al]

Good grief... You couldn't make it up.

Al.

 

[rtbcomp]

Have you got the earth lead attached? A plasma will just about manage to gouge (or even cut very thin sheet) without the earth lead on, but it'll ruin the consumables.

............

There is usually a timer to limit the time the HF pilot arc runs for, so if it runs for a few seconds and then stops, and releasing the trigger and starting again restarts the arc, the earth could be bad.

 

[astro_al]

I don't think the earth was bad (maybe not great, but functional). Lots of plasmas cut out on a bad earth anyway. I think its just very bad feed rates / settings. It ran too long and was a bit too effective at cutting 10mm to be the pilot arc alone.

Al.