Another plasma component...

JTknives wrote:

is that a genuine machine torch or fabricated?

thanks very nice

Pretty wild enhancement Phill. It will be good to see feedback about hole cutting as users get into testing it.
So now you need to add a feature to spot hole centres if less than a user specified diameter (eg < 6mm). This will be dependent a bit on the user's build quality re backlash, rigidity etc. Probably needs to be able to set from gcode to allow for variations in thickness.

phillc54 wrote:

Would you need to be able to adjust current to do this or would a timed torch pulse be adequate?

I just turn it off when I get an ArcOK. Thats nice and simple. Possibly timing would be useful as ArcOK can put a fair divot in thicker material. Not many people can control current but perhaps its an option too. Robertspark or Stefan would have a better idea. I know Beefy in Melbourne has played around with monitoring the current with a current sensor and killing the arc at a certain threshold but that requires adding electronics inside a plasma cutter.

With regards to plasma center punch, I'd suggest having a read of the Hypertherm 45XP Operator manual as the 45XP does plasma marking and dimpling.

Yes I know this may not apply to you, but my point is that you at least consider how they do it. i.e. set the amperage on the lowest setting, increase the pierce height and for dimpling, giving the pulse a VERY fast pulse.

www.hypertherm.com/Download?fileId=HYP172110&zip=False

PDF page 117

ALSO the cut table is on 137 (for air)

For dimpling, the recommended current is 10A, at a pierce (dimple) height of 6.4mm (0.25"), with a delay time listed as 0.05 Seconds.

Also if you look the air pressure may need to be lowered, given for something like "standard shielded 45A consumables" the airflow is 390scfh (standard cubic feet / hour [cold]), and for the marking / dimpling it is 300scfh. the "may need to be is based upon the airflow being lower, but the 45XP has marking consumables and cutting consumables...... they "may" have different orifice sizes.... which will lower the flow too. The point being have a play and see what works for you, but if you machine can fire the torch on and off fast you are most of the way there.

Hmm, Phill, you helped me find a bug in my post processor.

This is three spots at 40 amps on 2mm mild steel, no pierce delay.


To actually cut something, you need a movement between M3 and M5 so the post processor moved 0.001mm which is insignificant. The post processor I based mine on used 0.0254 mm for the move.

Remembering that a plasma is more like a blunt axe than a precision milling machine, these have proved accurate enough for drilling if you use the normal 1.0mm larger drill than the bolt. But clearly you are not going to spot to drill 1mm diameter holes but 4mm has proven OK.