Question for Jim Colt

[grgdmsn]

Jim you responded to a post of mine and I then asked you a question in it. My guess is you did not go back and read anymore responses in the post so you did not see the question. At least two of us would like to see what you have to say about the question. I have copied it here from the orignal post/threads.

Originally Posted by grgdmsn
Jim, I am very confused. Nowhere do I see amperage settings on the charts. I am not using fine cut at this point so I have not looked at those charts. The chart for the 65, page 3-33 of manual shows settings for 1. Material Thickness 2. Torch-to-work distance 3. Initial Pierce height 4. Pierce delay time 5. Best quality settings (cut speed and VOLTAGE) and 6. Production Settings. In another post I saw this comment from you on the HT PM65 "Let me know what cut specs you are using.....and yes, the cut charts are designed for use at max amperage (65 amps for a 65 amp nozzle)....the exception to that is with the FineCut parts that use different amperages for different materials, as listed on the charts." Also the chart on 3-33 shows the 65 starting at 16ga and has settings for it. So now I am very confused. You say the chart is for use at the setting 65amps but you also say to use the charts and to adjust the amperage and that 16ga should be at 45amp? You also say I won't get best quality if I use the 65A setting on everything, but I don't see amp settings anywhere else and you say the chart is for using at 65Amps. I am not sure what to think at this point. Can you please get me straightened out. Thanks.
Greg Mason

I'm looking forward to Jim's reply on this one too !!

I tried cutting some fairly complex artwork the other day on some .060 aluminum, and I used the setting recommended by Hypertherm. Even though I dialed back the amperage (to 35amps using 45amp consumables) I was unable to get fine detail. What I mean by this, is that if a cut path was within .060 of an edge, the arc would just melt into the edge.
Another thing I'm confused at is the pierce height on real thin material. Tom at CandCNC told me to just ignore the pierce height and just use the cut height with no delay. The cuts were much better( no keyholing) but I'm concerned about spray back into my tip , thus reducing it's life. Thicker material doesn't seem to be an issue.
I would like to try the 30 amp consumables to see how small of a kerf it will produce. Afterall, cutting real thin material using 45 amp consumables is like using a 5 lb sledge hammer on a finishing nail

Hopefully you can clear this up for Dan and me and maybe others. Thanks in advance for checking this posts and responding with your expertise.
Greg Mason

[jimcolt]

For the first questions....and I don't recall if I ever answered this specific post..

The mechanized cut charts in all of the Hypertherm manuals...including the Powermax65 list the cutting amperage. I am reading the Powermax 65 chart right at the moment....it says "65 Amp shielded consumables" at the top of the page....then scrolls down to individual settings for various thicknesses from 16 ga to 1".....all of which are cut at 65 amps but at different speeds, pierce heights and pierce delay times. If the chart is for using the 65 amp consumables....then all of the specifications in the chart are for an amperage setting of 65 amps.

The issue that a lot of users run into....is that there are a lot of different cnc plasma cutting machine designs....and many of them simply cannot cut with any level of accuracy at high speeds. One of my cnc machines cuts well at up to 320 inches per minute, the other gets unstable above 140 inches per minute.

So.....if you have to slow the machine down to get the best cut path following ability....you then should reduce the amperage in an attempt to match the plasma process to the cut speed capability. If you are using a 65 amp nozzle and you turn the amperage below 65 amps....the plasma arc loses energy density (rated as amps per square inch) and is not as stiff, and has lower gas velocity. This tends to produce a wider kerf, warpage and a less square cut edge.

The cut chart in front of me says to cut 16 ga steel at 65 amps at 370 inches per minute. neither of my cutting machines will do that.....so my choice is to simply reduce the amperage and try cutting slower.....or to put in a nozzle that has a smaller orifice and a lower amperage rating.....allowing me to cut at a speed that my cutting machine can handle.

The choices with a Powermax65...use the 45 amp shielded parts on that 16 ga.....the chart says 350 inches per minute....still too fast.....so I look at the FineCut consumable chart and it says 250 inches per minute for 16 ga. This is my best choice....it will allow the cutting machine to be stable and the cut quality will be nice.

Could Hypertherm provide cut data that provides the best speeds for cutting 16 gauge with the 65 amp shielded consumables at slower speeds....perhaps 150 ipm? yes.....however we likely would have a couple of hundred pages of cut charts at many various amperage/consumable/thickness ranges and it would make the process even more confusing! I suggest choosing the consumable and amperage and consumable sets that best matches your cutting machines speed capability...and use that combination. Experiment with amperage and speed to fine tune.....but always leave the amperage for a given nozzle at or below its advertised rating....and always cut at the recommended height.

The second part of the post....regarding intricate cutting:

When cutting thin (.060") aluminum with the 45 amp shielded process....I would expect the kerf width to be approximately .038" to .040" if you are ctting at the recommended cut speed listed in the cut charts. If you have chosen to cut slower, the kerf width will be wider. I am assuming that you have a Powermax45 as you mention using the 30 amp consumables.....if so these consumables will provide a kerf width that is about .006" to .010" narrower as compared to the 45 amp shielded consumables....they should help with more intricate parts.....however, cutting .060" away from an edge is asking too much from the plasma process. The .060" strip of aluminum will get very hot, will likely warp and will have heavy dross. I try to keep my cuts at least 1/8" (.120") away from an edge. A laser or water jet process can handle much finer details than a plasma on thin materials....at a much higher operating cost and purchase price.

We are talking about air plasma cutting systems here on entry level...low cost cnc machines. There is another whole side to plasma cutting with high definition plasma cutting on precision industrial cnc cutting machines....many of which can maintain great accuracy at cutting speeds up to 500 inches per minute!

The questions were rather complex on this post....so my answers can be a bit convoluted....i'd be happy to clarify any areas that need clarification!

Best regards, Jim Colt

Picture of an aluminum cut with the 45 amp shielded process at 45 amps....090" aluminum with good detail.

Originally Posted by grgdmsn Jim you responded to a post of mine and I then asked you a question in it. My guess is you did not go back and read anymore responses in the post so you did not see the question. At least two of us would like to see what you have to say about the question. I have copied it here from the orignal post/threads. Originally Posted by grgdmsn Jim, I am very confused. Nowhere do I see amperage settings on the charts. I am not using fine cut at this point so I have not looked at those charts. The chart for the 65, page 3-33 of manual shows settings for 1. Material Thickness 2. Torch-to-work distance 3. Initial Pierce height 4. Pierce delay time 5. Best quality settings (cut speed and VOLTAGE) and 6. Production Settings. In another post I saw this comment from you on the HT PM65 "Let me know what cut specs you are using.....and yes, the cut charts are designed for use at max amperage (65 amps for a 65 amp nozzle)....the exception to that is with the FineCut parts that use different amperages for different materials, as listed on the charts." Also the chart on 3-33 shows the 65 starting at 16ga and has settings for it. So now I am very confused. You say the chart is for use at the setting 65amps but you also say to use the charts and to adjust the amperage and that 16ga should be at 45amp? You also say I won't get best quality if I use the 65A setting on everything, but I don't see amp settings anywhere else and you say the chart is for using at 65Amps. I am not sure what to think at this point. Can you please get me straightened out. Thanks. Greg Mason I'm looking forward to Jim's reply on this one too !! I tried cutting some fairly complex artwork the other day on some .060 aluminum, and I used the setting recommended by Hypertherm. Even though I dialed back the amperage (to 35amps using 45amp consumables) I was unable to get fine detail. What I mean by this, is that if a cut path was within .060 of an edge, the arc would just melt into the edge. Another thing I'm confused at is the pierce height on real thin material. Tom at CandCNC told me to just ignore the pierce height and just use the cut height with no delay. The cuts were much better( no keyholing) but I'm concerned about spray back into my tip , thus reducing it's life. Thicker material doesn't seem to be an issue. I would like to try the 30 amp consumables to see how small of a kerf it will produce. Afterall, cutting real thin material using 45 amp consumables is like using a 5 lb sledge hammer on a finishing nail Hopefully you can clear this up for Dan and me and maybe others. Thanks in advance for checking this posts and responding with your expertise. Greg Mason

[grgdmsn]

Jim, thanks for the quick response and it all makes more sense to me. If I am understanding this correctly, I could use 45A consumables on my 65 and adjust the amperage accordingly? If that is correct, no need to straighten me out again. I did not know the cutting speed vs amperage was to be considered and would explain why some of my cuts at slower feed rates are inconsistent so I will work on dialing all that in. I get better at this and undertanding it more everyday thanks to people like you. I do know that I am fastlly using up my cut off pile of sheet material. I hope DANNO reads the response to the second question since it was from him but it helped me out too since I plan on cutting AL. Thanks again.
Greg

[jimcolt]

The cut charts supplied in the Hypertherm manuals are the result of our process engineers dialing in the best cut quality in our labs for each power level and thickness of material. The cuts are most often done at the maximum power rating for each nozzle. We could do cut charts for a 45 amp nozzle at 30, 31, 32 , 33, 34 amps....on up to 45.....but as you can easily conclude...that would provide for a lot of confusing cut charts.

Each nozzle has a current rating....that is where the nozzle provides maximum energy density with an acceptable life. If you cut with a nozzle designed for 45 amps....at 50 amps....expect good cut quality for a short period of time as the nozzle orifice will erode. If you cut with a 45 amp nozzle at less than 45 amps....expect effects such as slower cut speeds and increased edge angularity.

Hypertherm provides more than one set of consumables for each of our systems....this allows you to match the power and cut quality as well as possible to the material you are cutting. Sometimes a little bit of experimentation will be necessary.


Jim Colt

Originally Posted by grgdmsn Jim, thanks for the quick response and it all makes more sense to me. If I am understanding this correctly, I could use 45A consumables on my 65 and adjust the amperage accordingly? If that is correct, no need to straighten me out again. I did not know the cutting speed vs amperage was to be considered and would explain why some of my cuts at slower feed rates are inconsistent so I will work on dialing all that in. I get better at this and undertanding it more everyday thanks to people like you. I do know that I am fastlly using up my cut off pile of sheet material. I hope DANNO reads the response to the second question since it was from him but it helped me out too since I plan on cutting AL. Thanks again. Greg

[Danno]

Thanks Jim for that excellent response !
Now that I think of it, what you say makes perfect sense. I guess the electrodes of a plasma machine are no different that the welding tips of an oxy-actylene torch. If I need to weld something very fine, I wont use a number 5 tip and dial back the gas, I will just use a smaller tip.
One question does come to mind though ! If the smallest electrode available is 30 amps, then why make the machine variable down to 20amps?

BTW; you were dead on my kerf width ! it is exactly .040

[mcv300]

I have a PM45 with machine torch, shielded tip , my cuts are mostly thin 1mm MS and SS.

I cut at 30A all the time with PM45 standard consumables , because my machine cannot go as fast as HT 45A cut speed recommendation

Is there any HT alternative consumables that are more suitable for my need ? Can I put PM30 consumables ?

[jimcolt]

If you look at the mechanized cut charts in your Powermax45 operators manual....you will find part numbers and cut specs for using the same 30 amp consumables that are used in the Powermax30.


Jim

Originally Posted by mcv300 I have a PM45 with machine torch, shielded tip , my cuts are mostly thin 1mm MS and SS. I cut at 30A all the time with PM45 standard consumables , because my machine cannot go as fast as HT 45A cut speed recommendation Is there any HT alternative consumables that are more suitable for my need ? Can I put PM30 consumables ?

[mcv300]

Originally Posted by jimcolt If you look at the mechanized cut charts in your Powermax45 operators manual....you will find part numbers and cut specs for using the same 30 amp consumables that are used in the Powermax30. Jim

Thank you Jim,

On page 3-8 PM 45 manual says:

" Unshielded consumables and the T30v ( Powermax30) 30A consumables are also available for use with the T45M "

Please confirm that I need following items to attach to my T45M :
220569 Deflector
220483 Retaining cap
220480 Nozzle
220479 Swirl Ring
220478 Electrode

or just the
220480 Nozzle
220479 Swirl Ring
220478 Electrode

Thank you for your info

[Danno]

Originally Posted by mcv300 Thank you Jim, On page 3-8 PM 45 manual says: " Unshielded consumables and the T30v ( Powermax30) 30A consumables are also available for use with the T45M " Please confirm that I need following items to attach to my T45M : 220569 Deflector 220483 Retaining cap 220480 Nozzle 220479 Swirl Ring 220478 Electrode or just the 220480 Nozzle 220479 Swirl Ring 220478 Electrode Thank you for your info

The consumables you need are all listed in the manual.
I would assume you need the deflector and retaining cap that goes with the 30amp consumables.
Dan

[jimcolt]

You need everything listed. The parts are non shielded and quite different as compared to the 45 amp shielded parts.....they will not interchange.


jim

Originally Posted by mcv300 Thank you Jim, On page 3-8 PM 45 manual says: " Unshielded consumables and the T30v ( Powermax30) 30A consumables are also available for use with the T45M " Please confirm that I need following items to attach to my T45M : 220569 Deflector 220483 Retaining cap 220480 Nozzle 220479 Swirl Ring 220478 Electrode or just the 220480 Nozzle 220479 Swirl Ring 220478 Electrode Thank you for your info

[Danno]

Originally Posted by jimcolt You need everything listed. The parts are non shielded and quite different as compared to the 45 amp shielded parts.....they will not interchange. jim

Jim;
I forgot to ask !! The consumables for the T30, are they designed to be used on the machine torch?
Just wondering if they have the small "lugs" on the cap designed for the hand torch.
Thanks, Dan

[jimcolt]

The Powermax30 is a non shielded torch....so there is no shield for drag cutting with a hand torch like there is with the 45. Because the power is limited to 30 amps the nozzle can be dragged directly on the plate. The Powermax30 consumables fit in the Powermax45 hand and machine torches.....both torches accept all of the same consumables.

I spent a lot of time cutting thin materials on my cnc machine with the Powermax45.....I never found the need to use the 30 amp parts. The machine I used the 45 on is a PlasmaCam DHC2 and it could cut pretty accurately as speeds up to about 250 inches per minute. I suspect the 30 amp parts will work better on a machine that has limitations on cutting speed. You can run the 30 amp parts ant any power level between 20 and 30 amps....you will have to experiment a bit with speeds....faster will minimize dross.


Jim


Jim

Originally Posted by Danno Jim; I forgot to ask !! The consumables for the T30, are they designed to be used on the machine torch? Just wondering if they have the small "lugs" on the cap designed for the hand torch. Thanks, Dan