What can I do to improve the life of my consumables?

[Hworks]

Hi, I just did some analysis to see what was causing these aweful cuts. Today I cut some circles with different settings using a used 85A tip that was in the torch since last week and may have 20 mins cutting time and then removed and cleaned all components and tried again, still ugly, next I replaced it with new and there was much improvement. So i believe the tips are at fault. I have a long, clean airstream about 200ft, dried then filtered, 20ft then regulated at the plasma, I have never seen oil residue, however my tips don't last.
Here are some pictures of bad cuts from tips. You see the cut profiles on the first 5 pics then a new tip beside old one and pic 7 shows new tip cut and last photo shows last hole being new tip.
I have a Dynatorch machine and up to now have used the THC default settings and pierce at Hypertherm specs but run my set point a few #s high to keep the tip out of the weeds so to speak. I also cut at best cut speed unless material is dirty then i will go slower.
My issue is i get these concave/convex edge profiles which i believe now comes from slight deterioration (oval orifice) of the tip. As is i would need to change tips every hour if cutting for a living, is that normal? Is it me piercing too low for my application?
Any suggestions??
P.S. One more thing for all you experts, my picture of tip components was before i started as i now see from my own preview picture that the retainer cap has several dirty orifices also which i cleaned after the first test cut.

[Stout]

Can you see any deformation in the nozzle? Is the electrode arc point in the dead center?

I had a similar issue that after about 10 minutes or so cutting 3/8" mild steel I'd start to get and angled kerf on one side. The electrode showed wear off-center which i guess caused the arc to be off-center and in turn caused arc wear on one side very quickly. It turned out to be a bad swirl ring. A quick replacement and I was surprised and happy at the same time.

I wondered why Hypertherm considered the swirl ring to be a consumable. I had never replaced it on this system.

[Hworks]

Stout,
I definately get deformation of the nozzle but my thing is it happens so quickly and the 85A nozzle i started with today had a 'nick' .
Now i have used a hand torch for years and only have a handful of spare consumables.
The machine torch, i buy a mininum of 10 in each size and i only cut 3-4 brackets in any given week.
I have read before about the swirl ring and have inspected it.
Thanks, Andy.

[jimcolt]

Can you provide more information....and I'll be happy to help you get the system dialed in?

-Shall I assume it is a Hypertherm plasma? What model?

- If Hypertherm...there is no consumable part called a "tip". Can you elaborate on what consumable parts (part numbers) you are using. A description....such as "85 amp shielded consumables" will help me understand what you are doing as well.

- any chance that you can identify the thickness of the materials being cut in the pictures....and at what specifications you are using to cut each material? (consumable set, amperage, pierce height, piece delay, cut height, cut speed)

- closeup pictures of a used nozzle showing the exit orifice (towards the plate), a used electrode and a used shield will help me dtermine the issue.


First thoughts.....but I need info above.....are that you are cutting with way too much amperage for the material being cut. I have been using a Powermax85 for over a year...and I don't think I could make it cut as bad as your pics show!

I have limited email access this week....but if you respond I'll work with you as I can. Attached pictures show wat you should expect out of a Hypertherm Powermax system....consumable life should be in the range of 600 to 1500 starts.

Jim Colt Hypertherm

[Hworks]

Jim,
I have a Pm1650 power source , purchased last June with a Duramax machine torch upgrade. I base my cut specs from literature for a Pm85 unless i use 100A consumables then i go back to the 1650 settings. I have attached pictures of my charts.
By 'tip' i am refering to the nozzle, my apologies.
My test cuts were using the 85A consumables but i get similar results from 45A and 65A also.
I followed chart specs as follows yesterday for 1/4" plate,
3/16" for pierce height
0.5 sec delay
cut at 100 in/min and also at 130in/min
Voltage = 123, 125, 127
I also can get a good clean edge like you show with new parts but not for long, I think i get premature wear.
I read this forum everyday, I have had this issue for months, I read that others get hundreds of pierces from a single nozzle, so i ask myself what am i doing wrong.
Recently i checked my torch with a square to make sure it was perpendicular which it is.
What i get with the nozzles are wear very quickly or a CRATER all on one side (WHAT CAUSES THAT) and that really shows up cutting circles eg, you get undercut at 3 o'clock on the outside of the kerf and also on inside if the kerf at 9 o'clock. Cutting larger shapes, i will keep my cut speed on the slow side and use these nozzles with wear, even then all of a sudden the arc will fail to penetrate fully.
Attached are pics of the only nozzles i have left that are used that i didn't throw away.
Thanks for your help,
Andy.

[ASTRO_AL]

How dry is your air?

Al

[jimcolt]

Andy,

The damage I see on your nozzles is clearly damage caused by piercing too close to the plate, in adequate pierce delay time, or operating the system in the expanded metal cutting mode (mode switch on front panel not in the cutting position. This only has to happen a couple of times, especially at higher power levels....the resulting blowback spatter damages the nozzle orifice....and you can not expect good cut quality after this damage occurs.

I am not familiar with thye settings on the Dynatorch height control....however I would suggest that you go back and review the pierce height, the cut height, and the pierce delay times and ensure that they are set exactly as the cut charts in your Hypertherm operators manual specifies.

The proper settings for cutting 1/4" steel with the 85 amp shielded consumables (these are right out of the manual) are:

Pierce height: .15"
Pierce delay: .5 seconds
Cut height: .06"
Best quality cut speed: 130 ipm
Arc voltage is suggested at 123....however you need to adjust this setting so that the cut height throughout the cut remains at .06". The voltage setting varies from torch height control manufacturers...the physical height is most important.

The above settings....as long as your machine is truly setting the torch at these heights....will provide for a uniform high speed cut with the 85 amp consumables on 1/4" steel....and assuming you have clean dry air should provide for hundreds of starts before the nozzle is worn to the point that it affects cut quality.

For best cut quality on 1/4" steel....follow the specifications exactly as the manual states for use with the 45 amp shielded consumables. These cuts will be much squarer and sharper....and due to the lower amperage you will get more starts out of a set of consumables. The 65 amps shielded consumables will provide cut quality in between the 45 amp and 85 amp processes.

The electrode in your picture appears to be about 1/2 consumed....under most conditions the electrode will last twice as long as the nozzle.

The actual cutting specs you should be using came with your Duramax torch on the provided CD....you should print out a copy and follow them exactly. I am away from my office all week, have limited access and could not easily access the Duramax torch specs....sorry!

Remember....the nozzle orifice shapes the plasma arc. The pierce heights, pierce delays and cut heights are carefully engineered by Hypertherm to properly preserve the life of the nozzle while providing the highest energy density. It only takes one or two bad pierces to reshape the orifice (blown back molten steel) and the energy density drops, and the shape of the arc changes with the orifice shape. If the orifice wears always to one side...often that indicates too short of a pierce delay (the torch starts moving before the pierce completely penetrates the plate).

Hope this helps...I'll work with you to get this resolved.

Best regards, Jim Colt

Originally Posted by Hworks Jim, I have a Pm1650 power source , purchased last June with a Duramax machine torch upgrade. I base my cut specs from literature for a Pm85 unless i use 100A consumables then i go back to the 1650 settings. I have attached pictures of my charts. By 'tip' i am refering to the nozzle, my apologies. My test cuts were using the 85A consumables but i get similar results from 45A and 65A also. I followed chart specs as follows yesterday for 1/4" plate, 3/16" for pierce height 0.5 sec delay cut at 100 in/min and also at 130in/min Voltage = 123, 125, 127 I also can get a good clean edge like you show with new parts but not for long, I think i get premature wear. I read this forum everyday, I have had this issue for months, I read that others get hundreds of pierces from a single nozzle, so i ask myself what am i doing wrong. Recently i checked my torch with a square to make sure it was perpendicular which it is. What i get with the nozzles are wear very quickly or a CRATER all on one side (WHAT CAUSES THAT) and that really shows up cutting circles eg, you get undercut at 3 o'clock on the outside of the kerf and also on inside if the kerf at 9 o'clock. Cutting larger shapes, i will keep my cut speed on the slow side and use these nozzles with wear, even then all of a sudden the arc will fail to penetrate fully. Attached are pics of the only nozzles i have left that are used that i didn't throw away. Thanks for your help, Andy.

[Hworks]

Jim,
Thanks for the technical info, that helps me determine the root of the problem, i am currently working on some samples to post, I cleared the table and removed and cleaned the slats today and had a 10x6 sheet of 3/16" steel nice and level and the torch perpendicular and had good results at 45A.
Over the previous weekend i tried modifying my lead-in's on 1/2' plate but have too much taper at 65A settings, will try again and post pics.
You can see from my previous post that my laminated charts are the correct ones for my torch, i got them from the Hyp website.
Thanks, Andy.

[Hworks]

Jim,
I just wanted to follow up and thank you for your help, since our last correspondence regarding poor cuts and damage to nozzles I had not lost a nozzle due to damage until yesterday (my fault) while piercing multiple holes in 1/4" stainless brackets.
So when did you say the NEW 1650 replacement is coming out with true hole technology?
Thanks,
Andy.

[jimcolt]

I am glad things are working better for you!

In regards to a replacement for the 1650....I know nothing about that.....and if I did I certainly could not talk about it unless we had already released a product. True Hole technology requires more than a plasma system....it requires CAM software, Torch Height control, CNC control and a Hypertherm HPRxd (not an air plasma!) in order to produce taper free, bolt ready holes. We will not see this technology with air plasma systems.

Best regards, Jim

Originally Posted by Hworks Jim, I just wanted to follow up and thank you for your help, since our last correspondence regarding poor cuts and damage to nozzles I had not lost a nozzle due to damage until yesterday (my fault) while piercing multiple holes in 1/4" stainless brackets. So when did you say the NEW 1650 replacement is coming out with true hole technology? Thanks, Andy.