I’ll be upping my number for sure, Erik @72Pony. I just somehow never came across that recommendation, and most of the stuff I cut, the air doesn’t ever seem to switch off at 10 seconds.
1 Like
Yeah I doubt you would ever have a rapid longer than 10 seconds… so unless you program in a pause… or pause to remove a tip up the only time the long post flow would be relevant is at the end… still important tho.
So that begs the question why allow an option less than 30 seconds if that is the minimum suggested?
I know a guy that’s pretty good about calling the manufacture and asking questions…. 
2 Likes
if you look at my picture of the pierce count the size of the material is 16’ x 21"…lol…
1 Like
yes…the only time the cooling post flow runs the full time is at the end…while the torch is running the air is going through the torch pushing the heat out with the plsama.
As soon as the torch stops cutting the post flow is there to cool off the interior of the torch…
’
Think of a furnace or other things that create heat…they all run fans after the heat source is turned off to cool the components slowly…
Cutting the cooling air off sudenly leaves the remaining heat to remain and cook , warp, melt, damage other parts…
take a infared camera or even a basic thermo-gun and look at the temp of the torch when it stops…watch it cool down with the air flow…it is pretty cool…no-pun intended…
4 Likes
I’be been thinking about your points for the last couple of days. I agree with you in terms of instituting a “best practice”, but my very unscientific experience contradicts what you’re saying a little bit, and I’d like to expand upon that some.
I changed my consumables four times during this cut. The first time I changed them was immediately after my 10 second post flow had shut off, and they were pretty hot still; not too hot to handle with bare hands, but a bit too hot to do so comfortably. Still, they were not nearly hot enough to warp or melt anything. The second time, I waited probably 30 seconds after my 10 second post flow had shut off, and while they were certainly still warm to the touch, they weren’t hot enough to offend my skin.
I’m certainly not arguing that a 20-30 second post flow wouldn’t still benefit the torch by allowing the consumables to completely cool down to ambient temperature at the end of a cut, but that’s not why yours lasted so much longer than mine. I’m going to guess you’re cutting at 30 amps!? I’m cutting at 45 amps. I think that’s the number one factor. And I think I remember you having a pretty extensive air drying setup, that’s the other biggie.
Like I said, I’m going to go to 30 seconds on post flow from now on, because air IS cheap. And I want to thank you for bringing this to my attention, because in all the settings I have discussed, nobody else has ever brought it up with me.
I think the next time I do a batch of these signs I’ll try to run them at 30 amps and see how the consumables look after 250 pierces, and maybe try to push them to 500 on the next part of the cut.
1 Like
I think when they’re worrying about heat and cooling down the consumables they’re worried about cooling down the hafnium. The hafnium during the cut and slightly after the cut will be in a liquid state. This is why running off a sheet and blasting an open area can cause the hafnium to be expelled from the nozzle. This is also the reason why very high cut Heights or just running your torch in open air can be really harmful to the consumables. The hafnium is usually why a electrode will grenade and then screw up the copper.
2 Likes
As @TinWhisperer stated the hafnium will become basically liquid. When the torch fires the hafnium gets to 3500 to 4000 degrees. The only thing keeping it in the electrode is the air keeping the copper cool as copper melts at around 2200 degrees. So if its that hot and the air is cut off to soon it will start falling out and melting the copper part of the electrode.
3 Likes
would this also cause the elecgtrode to warp ever so slightly and then in turn result in a deformed or off center arc that then in turn deforms the cap and produces angled plasma cuts?
so I have no idea where you get this assumption from?..and you are way off…way off…
yes I do…and this is one of the main reasons I get great pierce counts on material not matter what gauge I am cutting.
so FYI…I have been cutting 3/8"…1/4"…and 3/16" a lot in the last few weeks and am still around 1000 pierces
good luck with your future cuts.
1 Like
Ok. Fine. I guess it’s all about the air then. Anyway, it was just an assumption based on the widely circulated cut chart and the fact that you said this was 16ga.
Alas, it is a shame that my 3 stage Motorguard setup doesn’t do a better job, because it wasn’t cheap, but even at 3x the consumable life, it would take a long time to offset the cost of an upgrade. But thank you for the advice that you have given. You’re really pushing the envelope of what’s possible with this equipment.
a great read on air drying…
I know you are trying…but remember it is not just your consumable cost to worry about…
time changing consumables
the cost of wrecked metal from a blown tip
time wasted resetting metal…and tips when things go wrong…
pennies add up to dollars very quickly…
3 Likes
I like this (in the article you referenced):
Adding a small desiccant dryer at the input of the plasma cutter to act as an indicator in the event of moisture in the supply air. If the beads even begin to show signs of moisture, then change them and also service the primary desiccant dryer by changing those beads.
What a great idea!
1 Like
if you look at most systems, like mine, you will see that is what I have…
but remember to put a micron filter just after the desiccant…this will keep any possible bead breakdown from getting into the plasma air line…very important.
my desiccant beads will last over 3000 pierces before I even consider changing it…and even then it is only about 1/3 changed…
1 Like