Woohoo! I finally bought a plasma cutter!

[gwagensteve]

I've been promising myself one for a long time, and I just got myself a plasma cutter- a BOC 40A model - runs on 240V, 15A socket.

There's a bit of a knack to using them - I'll need some guides etc to get nice straight cuts - otherwise it tends to look like you've scribbled all over the plate like a toddler , but it's so quick and quiet it's amazing.

Thing is, I have to learn how to make things again - lots of things are possible now that were very hard before - like tight inside radii - not easy to achieve with a jigsaw or grinder.

I'm a happy chappy!

Steve.

[mightymouse]

They are a good bit of gear - and you don't have the gas bottle useage of the traditional oxy torch.

I've been pondering a purchase for some time but just havn't got around to it as usual.
And it good to be able to cut alloy/ stainless etc etc.

[cj!]

It's already been put to good use

[gwagensteve]

And it good to be able to cut alloy/ stainless etc etc.

for sure - I've already cut the relief in Chris's skidplate for the front driveshaft. That's 5mm alloy in some sort of crazy grade - very hard to cut conventionally- and a tight inside radius too- 10 seconds work with the plasma cutter.

Steve.

[cj!]

It also seems to cut 10mm steel ok too.

[christover1]

You will have lots of best friends now

[gwagensteve]

Only if they want want whatever they have to cut stuffed up (at the moment)

There's a fair knack to using one, and it's fair to say I don't have it yet.

Steve.

[dank]

Hey Steve some people might not know exactly how a plasma cutter works...including myself... . All i know is that it cuts using something like a superheated jet of gas? Does it give a neat edged cut or does it need work to finish it?

[mightymouse]

"There's a fair knack to using it"........

One that I dont have unfortunately, on some cuts I get it right first time with an almost sawn edge finish and then on others its a mess. it seems that the start is critical ( at least for me ) get that right and its cool.

Surface finish also seems to play a big part as the tip contacts the material whilst cutting. Spend a little time getting a smooth surface before you start and the evenness of the cut is improved significantly.

Its also interesting just how efficient the little beasties are - even small single phase units will cut surprisingly thick material.

Yonks ago had a plasma attachement for a TIG unit, used argon instead of compressed air. Worked very well but cost a fortune in gas so its not an option I consider nowadays.

[gwagensteve]

Hey Steve some people might not know exactly how a plasma cutter works...including myself... . All i know is that it cuts using something like a superheated jet of gas? Does it give a neat edged cut or does it need work to finish it?

from reading the manual, there's a hafnium (really!) electrode inside the torch. when in use, an arc is struck onto the part surface inside the flow of air, the flow of air becomes unstable in the arc and the resulting flow of plasma or superheated gas reaches around 15000˚C

http://en.wikipedia.org/wiki/Plasma_cutter

If held steady against a guide, the result is quite clean. It does have a wave like contour across the cut edge, but it's quick to clean with a flap disk. There's also some oxy cut like dags of material on the back of the cut, but these tap off with a cold chisel.

Obviously the real key is moving the torch is a smooth, controlled way, but this can be done against a guide.

Generally, the item being cut doesn't get anywhere near as hot as with gas cutting - it's about on a par with grinding, if the plasma is being done properly. You can touch the workpiece shortly after cutting, and while it's hot, it's not hot enough to burn.

Steve.