I don’t think I could cite chapter and verse. It is more from accumulating a mass of info, then trying to put it all together into something that makes sense to me.
Mostly it is seeing how the delay in smart voltage handles the initial unstable period of the cut as explained by Langmuir, and seeing also that inserting a delay manually when using nominal doesn’t seem possible, I concluded (perhaps incorrectly) that the first portions of each cut loop could be a bit wonky.
Are you saying that this is not the case?
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They will work very similar see with smart voltage you have a sample period in which it determines the voltage reading. It is necessary to have the correct height at that point. My understanding it is within a very short time frame. With nominal when the torch fires and fire control sees the voltage isn’t correct it will change to make it.
One time I had hunting happening and it was because I changed the speed that the torch will correct itself. This did cause issues cutting a.radius
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That was how I reasoned it out too. Firecontrol ignores the first wild voltage swings for about 1/4" by default, then samples for the next 1/4" when the flame is Hopefully stable, then turns thc on after about 1/2". These settings are adjustable if one wants.
However there is no such delay when using nominal, the thc is turned on as soon as the torch drops to cut height. The thc will then be trying to compensate during this unstable time,raising and lowering the torch untill it finally does stabilize.
From what Langmuir says, I concluded this distance to be about 1/2" or so.
With all your stuff, have you found it to be inconsequencial?
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I have never seen any issues at all. I can understand your reasoning in a since. Me on the other hand I think the torch stabilizes faster ( during you lead in) and it’s all good. With that I generally use as long of a lead as possible up to say 1/4 on thin material.
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Yea, I try to use as long a leadin too, for that very same reason, even using smart voltage.
But with some of my more insane contours I have had to drop the leadin to 0.03" to fit it in and was too chicken to not use smart voltage!
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I understand. Design a small trip piece to mimic the contours you are concerned with and do a few tests cuts. I believe you will be surprised.
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While I don’t use nominal, I can’t see how it’ll affect intricate designs in a negative manner.
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That was going to be my next question to you Phillip. With all the artwork you have done using nominal you havent had any untoward results? I use mostly 14ga. Maybe i will try it after all, as I mentioned , I have just been going on book learning!
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Unless you have a issue with your setup you won’t see any unwanted effects from nominal. Even with intricate details.
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Where did you get this information?
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The part about smart voltage is from Langmuirs own information on their THC module. It is at the end of the installation section and it gives a run down of what all the bells and whistles do in their system.
The part about nominal is from looking at any G code file in notepad++. You will see that the THC on command (H1) comes immediately after the torch drops to cut height ( G1 Zxx Fxx). It does not come after either an X or Y move.
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The Hypertherm nominal voltages have been dead nuts on; my cut heights are .059-.060 every time I have checked with feeler gauge. You are over thinking…
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This makes more sense than the fixed delays implied by your note. This would then be directly tied to pierce delay.
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Ok my first cut was 1/2”.
I tried smart voltage for the first set of parts and it was reading 141Volts
2nd set, I set nominal 140V (what Hypertherm calls for)
So my take away was, I must have the settings in fusion set pretty much dead on for smart voltage, if the 2 were so close. Am I correct thinking that?
I will continue to test when I am cutting some thinner sheet.
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I would say yes you should be very close. I don’t know but am curious to know how the correlation between say how many volts between say .010 in cut height.
I have these figures somewhere in an older post of mine, describing exactly how many volts = how many tenths it’d change.
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Yep, exactly why I stuck with smartvoltage.
Especially for anything thicker than 16 gauge, material just doesn’t flex much to worry about IHS probing incorrectly.
Also, source of said metal can have the tiniest effect on conductivity which is why that 1v difference makes less of a change than say, the condition of the cartridge/consumables being used.
Hi Tom,
It is only tied to pierce delay in that it follows directly on its heels.
When selecting smart voltage, Firecontrol manipulates the G code in order to insert these fixed, but selectable, delays. It does not show up in the G code however. How they do this I do not know, I have contacted Langmuir with this very question but haven’t as yet received a reply.
The fact that they do do it is evident from their explanation of how the smart voltage works.
What I am trying to discover is how to do something similar when using nominal voltage to avoid all the things that smart voltage avoids as described in their explanation.
@curmudgeon I promise you are way overthinking this. The thing to understand you don’t need the as you call a delay the sampling period with nominal. Nominal doesn’t have do determine and “lock in on a voltage”. Tht voltage is predetermined by you setting the voltage.
With smart or nominal it will adjust in the same timeframe.
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With nominal there really wont be any adjustment would there? It would be what ever you set instantly.
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