Stainless Steel

[waterfxmatt]

I solely cut 10ga and 12ga SS using a Hypertherm1650 on a dynatorch table.

I am wondering what I should be expecting from my consumables. Presently I am only getting about 1000" and 100 pierces from each set. I am using the fine cut 40amp with the 220404 cap as suggested in other posts.


Is this normal?

[jimcolt]

You should be able to do better than that. I would expect 300-400 starts with the FineCut consumables assuming:

1. Clean, dry, oil free air
2. Proper pierce height for every pierce (good torch height control)
3. Operating at the recommended amperage.
4. Proper pierce delay time.
5. Proper cut height.

If the air is clean and the torch height control is working correctly (all pierces at correct height) then your consumables will perform best.

Jim Colt

[waterfxmatt]

I wish I could get 300-400.

I have tried settings in manual, and while cut quality is superb, I am only getting 40-50 starts. In some cases i have to changes the tips out several times per sheet of material cut.

Leon Drake @ Dyantorch questioned the low Set Point (63 per the manual), so I started at 90 and started working down. At around Set Point 72, 45amps, 95IPM I get a decent cut that I can live with (though only half as good as the cuts with the Hypertherm manual settings) and I can get about double the life from my tips.

In response to your comments:
1.) We are located in Vegas, so air is very dry. I also have air filters/water traps at the compressor, at the end of the manifold where the table and plasma plug into, and the Hypertherm air filtration kit (#128647) on the unit.

2.) We do have the DASH sensor from Dyantorch for our torch height control. I have gotten at cut level with a welders mask and steel rule and it is piercing at the set height (3/16")

3.) I am running at 45 amps.

4.) I have 0 pierce delay. I did not see one listed one listed on the fine cut page.

5.) I am cutting at the right height. With the 220404 cap on, it is just barely off the sheet, and I believe the cap extends past the nozzle by about the .0100" listed in the manual.

I am at wits end here. I guess I just need to resign myself to purchasing consumables by the pallet load.

[jimcolt]

As I said, you should be doing better. Use the Hypertherm air pressure setting...as that is the way our engineers designed the torch.

A pierce delay setting is 100% necessary....this allows the torch to stay at pierce height until the arc is stable, and the molten metal is blowing down through the kerf. I would use about .4 seconds pierce delay on 12 gauge.

Torch to work distance when using the 404 shield should be .01" on SS, if you have a way of referencing arc voltage it should be in the range of 77 to 82 arc volts. Pierce height should be in the .120" area......if the pierce height is too high it keeps the pilot arc on for a longer period of time, and erodes the front of the nozzle orifice more rapidly.

I would suggest operating the Fine Cut consumables at no more than 40 Amps for best life.....I know the manual shows them running up to 50......but trust me, the life will be better at lower power levels.

Regardless of the relative humidity, keep a close watch on your air supply for moisture. This time of year it is the number one cause of calls to our tech service line in regards to consumable life. Most users do not believe this and would like to find something else that affects consumable life.

Can you provide some good digital photos of the outer nozzle orifice, the outer shield orifice, and the hafnium emmitter end of the electrode (a used up set). This may help me troubleshoot what is going wrong here.

Don't buy that pallet load of consumables yet!

Jim Colt

[waterfxmatt]

Here are some pictures and some background. This was half a 4x8 sheet with 19 parts. Some as small as 3"x2", largest about 18"x18". I put completely fresh setup on the torch; Cap, Electrode, Cover and swirl ring.

Was able to cut the first 16 parts with only 2 stops, software said lost arc voltage. Happened both time when piercing. Was able to restart both times. The 3rd stop was mid part, right over support rib on the table underneath. Could not get it to restart, failed twice, so I changed the tip (electrode and nozzle).

Finished cutting the 3 parts with no stops.

Here are both sets of electrodes, nozzles and the cover:




Here is first set with 25 starts:




Here is second set with 3 starts:



Click on the pictures for a much higher res version

[jimcolt]

I cannot see the condition of the orifice on the nozzles from your pictures. There is no way that these parts are even 1% used up.....I would have to say that there is likely a momentary anomaly that may be causing a misfire. Could be a restricted airline causing a momentary pressure drop.....or an electrical noise issue that is causing the start input to bounce.

The electrodes look new. From the blurry pics of the nozzle they look ok, but hard to tell.

Do you have the front panel selector switch in the cut position? If it is in either the gouging or the continuous pilot condition you could get abnormal wear.

Do you have a ground rod driven for the machine? What is "setpoint 72".....does that mean 72 arc volts?

Jim

[waterfxmatt]

The nozzle openings are still round and about the same size as when new.

I do have the front panel set to cut.

I do have a 6ft grounding rod driven into the ground.

Yes..s.et point is voltage...the Dyantorch software refers to it as SetPoint, sorry for the confusion.

I am intrigued that you feel these are barely worn in any way. When I change to new tips it will cut fine until about the same amount of wear is present.

I have verified all my airlines...and even have a pressure gauge on the hose going from the wall connection to the plasma unit itself..and have monitored it and seen no drops in pressure to the machine. The cable from the plasm to the torch is ran nice and straight and there is no kinking when the gantry is travelling about the table.

I have spoken with Leon at Dynatorch about possible noise, and he told me to watch for the "plasma" icon on the software to see if there is an flickering. I have stared at that icon for so long that the image was burned into my skull and see no flickering.

One thing...you mentioned earlier that at 73 arc volts, when piercing i should be in the 77 to 82 range....after watching the cuts...i am piercing in the 58 to 62 range, then the voltage comes up and flickers between 72-73 for the cut.

Any ideas, suggestions...anything I will try and get back with you.

[jimcolt]

Something is strange with your arc voltage settings. Arc voltage means nothing during the pierce, only during steady state cutting at constants speed. For piercing your Dynatorch system uses optics or sonar type device to find the surface of the plate, then should index down to whatever you set for pierce height. I recomend this to be in the .012" range for 12 gauge stainless. As soon as the plasma arc transfers to the plate, the pierce delay timer starts, and if you have .4 seconds set for this function...then the torch should index down to a preset cut height after.4 sec. The cut height should be .01 " (measured from the lowest part of the torch to the plate). At this same thime the x and y motion should start, and once the motion gets within about 20% of the full programmed speed (set by you), then the THC will start monitoring arc voltage, and adjusting the torch height by maintaining the arc voltage setting that you have set.

Arc voltage is proportional to height, but is affected by cut speed, material thickness, power level (amps) and consumable wear. In the Hypertherm manual we provide a recomended arc voltage, but with so many variables the operator must learn to adjust the arc voltage in order to maintain the recomended cut height (.010" for cutting stainless with FineCut consumables). A higher voltage will increase torch height, a lower voltage will decrease height. Once again....this arc voltage height control function is only correcting torch height during steady state cutting.....and is just a redundant readout during piercing. From your arc voltage setting....it seems to me that the torch is not running at .01" off the plate, and incorrect height will cause poor cut quality as well as damaging consumables.

It sounds as though you are changing consumables due to the fact that they stop firing......after as little as a few starts....and from the pictures I see no issues with the consumables that should cause this misfiring. Hypertherm consumables should not start nisfiring until near the end of their usable life, which shoule be in the 250 to 500 start range depending on what you are cutting as well as the average duration of each individual cut cycle. Here are some things that cause premature misfiring on a blowback style plasma torch:

1. Overtightened retaining cap. Should only be snug.
2. incorrect torch air pressure.
3. moisture in the air. (the only true moisture free air systems will have either a refrigerated air dryer or a properly maintained dessicant dryer system)
4. Damaged swirl ring
5. Used up consumables....usually the electrode will have a pit depth of .030" or more as compared to a new one, and the front of the electrode will be carbonized, as well as carbonization on the inside of the nozzle.....often these parts can be cleaned with a gentle abrasive such as scotchbrite, and will continue to operate.
6. Defective or damaged torch plunger mechanism.

Jim

[WereWoof]

I know this is a little bit out of date.

You state you are only getting a certain number of starts per consumable (tip and electrode), but what indicates to you that they have reached the end of life? Is the torch failing to start reliably? Is cut quality becoming unacceptable?

If it is the torch not starting reliably then there are several possible reasons for that, that I know of, with the hypertherm plasma units. I have a hypertherm 1250 which is the cousin of the one you are using and has several idiosyncrasies that about drove me nuts when I was first setting up this machine, with failure to start on certain cuts until I finally figured out the causes. (which I really should discuss in a new thread)

Please let us know how its going and if you got it resolved.

Also, I use the same consumables and would totally agree with Jim Colt, in that those shown in the picture have much MUCH more life left in them.

LUCK!!

dave

[waterfxmatt]

The unit would just stop cutting with any consistancy unless I changed the setup.

I tried all combination of settings as recomended by Jim Colt and Dyantorch. I have finally got it working much better. I can cut anywhere from 15-20 full sheets of parts with a single setup now.

I am piercing much higher and with a longer delay than recomended (3/16"-1/4" pierce height and 1 second pierce delay). This seems to help the arc stabilize and not bring the torch too close to the material at the start of the cut. I am also varying my voltage anywhere from 82-90 during the cut to keep the torch about 1/8"-3/16" above the material. If I try to cut any closer The torch has many starts and stops from losing the arc.

I am not sure why I have to vary so much from the recomended settings...but it is working for me and the edge quality of the cut is acceptable.

[WereWoof]

howdy!

good that you got it working better, but there is still something that isnt right about how its working for ya... I mean great that you are getting by with much better consumable life.

Perhaps if you keep working with it as you get more experience, something will come to light. One thing that seems obvious, but is easy to overlook is making sure that there is a good ground to the work. By that, I mean all the way from the ground terminal in the plasma to the work piece.

Piercing at that height does sound a bit high too, but as long as you are getting good arc transfer to the work, its not a big deal. Why you would have an unreliable arc at lower tip height is quite puzzling tho. I will continue to think about it over a few days and post if anything pops into my head. Using the same consumables, I have also found that cutting within that voltage range works well for us. Generally we keep the voltage set to about 85 volts. It still cuts well below that voltage, but with galvanized and lasergard coated stainless we tend to accumulate a ball of slag on the torch tip that can cause problems and annoys the heck out of me.

Good luck!

dave

[jimcolt]

The pierce height sounds excessive compared to my Hypertherm Powermax45.....however the voltage settings vary from machine to machine (different THC calibration) as well as different feedrates, gas pressures and consumable wear conditions. The voltag recomendations in the manual are generally close starting points....the more important height control parameter is physical height...adjust the voltage until the physical standoff recomended in the manual is correct.

Jim Colt