How Many Pierces per consumable?

[SONIC]

Hey Guys,
How many pierces do you guys get before you change consumables?
I run the same file a lot (production of brackets) and I'm only getting about 270 starts per consumable set (1 sheet)
While this is not terrible, it seems too low to me, I'm going through a lot of consumables as I have to change them every time I load the machine to get it to reliably cut.

Once they are "done" they look fine and cut fine, but they start misfiring/stuck consumables code.
I've done all the troubleshooting for stuck consumables. Have a nice new air dryer, new swirl rings, new o-ring, full pressure at plasma, etc etc.

I've seen posts where guys are getting several thousand pierces from one set, so my 270 seems way too low.

I could probably get 1000 pierces, but I would have to constantly babysit and hit "torch fire" every other pierce.

I have to say so far I am just unimpressed with this level of plasma cutter. Yes it's cool to be able to do this stuff, but if I have to sit there and babysit the damn thing all day it's cheaper to pay someone else to cut stuff rather than pay myself to sit on my ass at the computer pushing go all day.

[little blue choo]

I have never counted how many pierces I get but have often wondered when I see post like this. I will start a log to night when I change them. Last night I cut 2 4x8 sheets of artsy stuff with a set of consumables that have cut several sheets before. I just did a job report on one of the larger files I cut last night and it had 374 pierces. I would guess I have over 1500 on this set. I had a couple of lines that didn't cut all the way through on my last piece so I will be changing them tonight.

Rick

[Brand X]

I am just guessing you have a 45XP?... since you did not include that info.. I would use the copper plus electrodes. It's not hype that they last over twice as long as standard stuff (to .500)

[SONIC]

BrandX, correct 45XP. Same issues with the PM65 before.
The problem I'm having is not that the electrode is worn out, in fact there's hardly a dimple.
The nozzles look okay too, not out of round and the cut quality is fine. It's just the damn misfires!

[motoguy]

Do you have debris or air in your lines? I know you have a new air dryer, but do you actually have dry air at the torch? Any chance debris could have been blown through the torch air lead at some point?

[little blue choo]

Are you running a water table? At one time I had a lot of misfires and found that after changing the anti-corrosive that I was using in my table the misfires all but went away. Until I change it, I would clean my consumables daily and that helped a lot.

Rick

[SONIC]

Motoguy, yeah the torch air is clean. It did have water in it before, but goes through 4 particulate filters before getting to the torch so it's clean.

Rick,
That's a thought. I am using sodium nitrite as a rust inhibitor in less than perfect (probably high) concentrations.
I also cut with the water touching the bottom of the sheet (to stop any warping) and it blows through the holes onto the torch often. However never when the post flow is off, so no water should be getting into the torch that I can imagine.

[SONIC]

Also how are you cleaning consumables? I can clean the electrode with a wire wheel, but can't get into the inside of the nozzle.

[tnbndr]

I can not say exactly how many pierces I get but my guess would be approximately 400-500 on 12 gauge and 10 gauge. Count goes down when I move to thicker material.
I am waiting on Dan at LDR to add a pierce counter to my Mach 3 screen so that I can accurately keep track.
UPDATE: Dan reads these forums and reached out to me and completed my Mach 3 Screen with pierce counter!!!! I'll have better infor in the near future.

[jimcolt]

The stuck consumables error code indicates (in most cases) that you have an air flow starvation at the inlet to the plasma. The other things that can cause the stuck consumables error code is when your pierce height is too low and the nozzle is in contact with the material....this blocks the airflow and does not allow the electrode to slide back, hence the "stuck consumables and misfire. A worn or damaged swirl ring will cause the same issue.It is more prone to occur if the consumables have a bit of wear, however the air inlet pressure issue should be fixed. I typically get over 1000 pierces with Finecut consumables before any misfires, I have gone to as many as 3000.

I always suggest a pressure gauge installed (hard plumbed) at the plasma inlet. Watch the gauge right as the torch starts.....when your compressor is at the low pressure point in its cycle. If the pressure gauge ever drops below 90 psi then that may be the issue. You cannot rely on the gauge back at your compressor. So, be sure your pierce height is actually achieving the height recommended in the cut charts for the material you are cutting...every time (ohmic contact works best for this), try changing your swirl ring, and install a pressure gauge at the inlet. Jim Colt Hypertherm

[SONIC]

Jim,
The first thing I did when having issues was read everything you ever said about stuck consumables on about 20 forums. I've done it all and no real improvement. The air dryer helped a lot, but still realistically I'm not over 300 before it's not reliable anymore.

[urbnsr]

Running 65 amps, I can get over 1100 pierces (if the moon is aligned with mars). But get one bad pierce and I only get a few hundred. If that.
The finecut nozzle seem to run forever, though, running at 40 amps +/-

[jimcolt]

Next time you start getting misfires on a set of consumables with less than about 600 starts....post good closeup pics of the nozzle orifice, the shield orifice, the inside of the shield and provide us with your cut specs....Amperage, pierce height, pierce delay and cut height. I can usually get an idea of the issue when I see this. In regards to the error codes....if you have tried everything I suggest and continue to get these codes...then a call to Hypertherm tech service is your best bet. In 6 years I have never seen the stuck consumable code on my Powermax85 in my home shop....I use Finecut consumables often. Misfires are very rare, but do happen near the end of consumable life.

Jim Colt Hypertherm

Jim,
The first thing I did when having issues was read everything you ever said about stuck consumables on about 20 forums. I've done it all and no real improvement. The air dryer helped a lot, but still realistically I'm not over 300 before it's not reliable anymore.

[SONIC]

Jim,
These started misfiring about 350 pierces in.

[little blue choo]

I just changed mine again today. My log shows 2448 pierces.

Rick

[SONIC]

I just changed mine again today. My log shows 2448 pierces.

Rick

Ya Bastard

[jimcolt]

I wanted to see the inside of the shield, inside down near the center orifice you will see some steel that has blown back inside the shield. It will coincide with the chuck of steel that can be seen on the face of the nozzle you show....and you will also see a notch in the nozzle shape. The only two things that allow steel to blow back inside the shield are 1. Piercing too close (even once), 2. Piercing with inadequate pierce delay time.

Too close or in contact with the material forces the molten metal from piercing inside the shield orifice. The pierce heights listed in the operator manual allow the molten metal to hit the shield, but not enter the shield orifice. If material goes inside the shield, it shorts the shield to the nozzle.....which completely negates the purpose of the shield....which is to electrically insulate the nozzle from becoming the same electrical potential as the material being cut. So...once the shield and the nozzle are at the same potential...the very next pierce allows an arc from the electrode to the nozzle/shield (same potential now) and another arc from the shield to the material (this is called "double arcing)...this double arc then notches the nozzle, changing the energy density of the arc and causing rapid nozzle wear.

The fix? Ensure that your pierce height is always correct. Not just set correct, but be sure that if it is set at .015" that it always rises to .015" above the material before the arc fires. Be sure that the pierce delay time is set at least to the delay listed in the cut charts in the operators manual. Some machines start their timing at different times...the number in the manual start the pierce delay time from arc transfer feedback (when the plasma arc transfers to the material, and is sensed by current flow on the work lead), while others start the timing signal from the arc start command (this will cause too short of a pierce delay). Be sure the pierce is fully complete and all the sparks are under the material before movement in the x, y or z axis occur. Increase pierce delay if necessary.

Your nozzle will still work if you clean the steel out of the shield and off the front of the nozzle, however it will cut with varying angularity because of the notch caused by double arcing.

If the shield orifice is round and is clean inside reuse it. Replace the nozzle. Your electrode still has about 90% life left.

I don't know what you have for a machine and height control. If you can use ohmic contact surface sensing....that is the best way to improve pierce height accuracy and repeatability.

Jim Colt Hypertherm

Jim,
These started misfiring about 350 pierces in.

[SONIC]

I wanted to see the inside of the shield, inside down near the center orifice you will see some steel that has blown back inside the shield. It will coincide with the chuck of steel that can be seen on the face of the nozzle you show....and you will also see a notch in the nozzle shape. The only two things that allow steel to blow back inside the shield are 1. Piercing too close (even once), 2. Piercing with inadequate pierce delay time.

Too close or in contact with the material forces the molten metal from piercing inside the shield orifice. The pierce heights listed in the operator manual allow the molten metal to hit the shield, but not enter the shield orifice. If material goes inside the shield, it shorts the shield to the nozzle.....which completely negates the purpose of the shield....which is to electrically insulate the nozzle from becoming the same electrical potential as the material being cut. So...once the shield and the nozzle are at the same potential...the very next pierce allows an arc from the electrode to the nozzle/shield (same potential now) and another arc from the shield to the material (this is called "double arcing)...this double arc then notches the nozzle, changing the energy density of the arc and causing rapid nozzle wear.

The fix? Ensure that your pierce height is always correct. Not just set correct, but be sure that if it is set at .015" that it always rises to .015" above the material before the arc fires. Be sure that the pierce delay time is set at least to the delay listed in the cut charts in the operators manual. Some machines start their timing at different times...the number in the manual start the pierce delay time from arc transfer feedback (when the plasma arc transfers to the material, and is sensed by current flow on the work lead), while others start the timing signal from the arc start command (this will cause too short of a pierce delay). Be sure the pierce is fully complete and all the sparks are under the material before movement in the x, y or z axis occur. Increase pierce delay if necessary.

Your nozzle will still work if you clean the steel out of the shield and off the front of the nozzle, however it will cut with varying angularity because of the notch caused by double arcing.

If the shield orifice is round and is clean inside reuse it. Replace the nozzle. Your electrode still has about 90% life left.

I don't know what you have for a machine and height control. If you can use ohmic contact surface sensing....that is the best way to improve pierce height accuracy and repeatability.

Jim Colt Hypertherm

Jim,
These started misfiring about 350 pierces in.

Jim,
pierce height is .15 (not .015 which I assume was a typo). I've checked it countless times. No ohmic but using 3/16 material so very little if any deflection.
I do cut a lot of .20" holes and the blowout of steel touches the shield sometimes when the machine proceeds to cut height, but I can't see any way around that?

[Jeffery71]

Is that metal blow back in the nozzle or is it arcing from the electrode? I can't tell from the picture.

I've never had metal blow back in the nozzles but have seen arcing on the inside of the nozzles. Also on the end of the electrodes..

[jimcolt]

It is normal to have dark gray swirl marks inside the nozzle, however from the pic of the inside of the nozzle the arc marks look like the first arc (electrode to inside of the nozzle) of a double arc, the second goes from the shield to the material being cut....this occurs when the shield is electrically shorted to the nozzle. The shield will short to the nozzle when piercing too close or inadequate pierce delay occurs.

The normal dark gray swirl marks are at pilot arc current levels, roughly 10 amps....so they do not damage the nozzle orifice. When you see deep gouges like the ones in the pic, that is a double arc that occurs after the current ramps up to cutting current....and it does damage the nozzle orifice.

My experience....which as of next week is 39 years of working for Hypertherm and plasma cutting...is that all materials under about 1/4" will move when sensing the material occasionally. It only needs to happen once. This is the reason Hypertherm developed the ohmic sensing on our height controls about 20 years ago. Why everyone doesn't use it is beyond me!

You can try a higher pierce height, though too high and the nozzle will develop a crater around the perimeter of the outer orifice exit. With a higher pierce height the pilot current (DC plasma arc from electode to nozzle) stays on for a longer duration and wears the nozzle more rapidly. You should be able to pierce at about .2" (sorry for the typos before!) without too much issue.

Jim Colt Hypertherm

[SONIC]

Thanks Jim,
I'll try changing the pierce height, but if there's any metal getting in I'm fairly certain it's from the plunge to .06 and not from piercing. Sometimes the metal doesn't go straight through and a small "ball" of molten metal will still be near the hole when it plunges. I can't see any way around this unless Its not an issue?

I appreciate the help.

[jimcolt]

It could get in from the " plunge" from pierce height to cut height only if your pierce delay time was too short. If it is not fully pierced and the plunge occurs, then you will get blowback inside the shield. Try a longer pierce delay if you think that is the issue. Jim

[SONIC]

I Ordered an ohmic setup so we shall see if that helps.