configurations question

[noplacetosail]

Hello,
Great forum! Thanks to all of you who post such valuable information. I am a newbee here. I am a welding instructor and own the http://www.weldguru.com site. My school just purchased a plasmacam DCH2 machine and a hypertherm 1250. I am still in the learning curve part of this project. I guess something that has surprised me is that the plasma companies haven't brought forth a complete configurations listing for different metal thicknesses. However, It is highly possible I am naive in saying this and if so I apologize. So, with hat in hand i shall ask;

Is there somewhere on this planet a chart for different metal thicknesses which lists start suggestions for the following; (yes i have the hypertherm manual cutting chart)

Cut speed (ipm):
Cutting height (inch):
Height for rapid travel (inch):
Height for pierce (inch):
Material thickness (inch/ga):
Time spent piercing hole (sec):
Continue cutting after stop (sec):
Z shift (inch):
Arc voltage shift (inch):

thank you for your time!

[Loyd]

You will find most of the info you request in the manual that came with the Hypertherm 1250. That is the machine I have
along with a plasmacam dhc.
Loyd
Here are some rough guidlines that work for me:

Cut speed (ipm): 120 ipm for 16ga mild steel 150 ipm for 20ga stainless .040 aluminum 50 ipm for 3/8
Cutting height (inch): .06 for most thin stuff .02 for thin stainless
Height for rapid travel (inch):
Height for pierce (inch): I usually pierce at .1 to.08
Material thickness (inch/ga): put in ga or decimal equiv.
Time spent piercing hole (sec): .05 for thin material .5 to .9 for 1/4 to 3/8 you just have to get a "feel" for it
Continue cutting after stop (sec): 0 is good
Z shift (inch):
Arc voltage shift (inch): You need to follow the instructions in the P.C. manual. Loosely, I have found if you are using a fine cut .7 is a good place to start. All other tips start at 1.2 and go from there.

[jimcolt]

Actually...the guidelines you are asking about....some are specific to the PlasmaCam machine you are using, and some are specific to the Powermax1250 you are using. All of the parameters for the 1250 can be found in the Hypertherm manual. The ones listed in red are out of the Hypertherm manual....although Hypertherm may use a different term for some of these specs!

Cut speed (ipm):
Cutting height (inch):
Height for rapid travel (inch):
Height for pierce (inch):
Material thickness (inch/ga):
Time spent piercing hole (sec):
Continue cutting after stop (sec):
Z shift (inch):
Arc voltage shift (inch):

Cut speed actually has two listings in the Hypertherm manual....optimal and Maximum.....for mechanized cutting the optimal speed will provide the best results.The cutting height is listed at the top of the Hypertherm cut charts...that is the recomended physical torch to work distance during steady state cutting. Height for rapid traverse is a PlasmaCam function that makes the torch retarct this distance before it allows a move to the next cut...to avoid collisions with tipped up parts. Height for pierce is important to get the best consumable life...it is listed in the Hypertherm cut charts...or you can just double the cut height for this. Material thickness is for the PlasmaCam height control to adjust its baseline settings...it eeds to be set before every differnt thickness is cut. Continue cutting after stop....this is a PlasmaCam function that keeps the arc on after the motion stops....it is useful if you are cutting thicker materials that cause the plasma arc to lag....this function allows the parts to disengage from the base metal. Z shift and Arc voltage shift should be left at default settings....use the "calibrate height before next cut" function in your PlasmaCam settings/THC menu to click this function...and it auto calibrates the z axis.

I have a DHC2 as well....so I'll be happy to help you out as you go!

Jim Colt

[noplacetosail]

Wow, thanks so much. another few quick questions;

1- what is the advantage/disadvantage of fine cut consumables with this machine versus the regular consumables?
2- corner acceleration setting
3- slower on circles under setting
4- we will be cutting primarily hot and cold rolled steel 3/16" and lighter (but mostly 14 gauge and lighter). I am all about minimizing various stocked consumables. Why would I not use strictly fine cut consumables?
5- In the hypertherm manual under fine cut consumables item shield # 120979 and shield # 220325 are listed but # 220325 is for CE systems. Hmmm, what is a CE system?

[jimcolt]

Wow, thanks so much. another few quick questions;

1- what is the advantage/disadvantage of fine cut consumables with this machine versus the regular consumables?
2- corner acceleration setting
3- slower on circles under setting
4- we will be cutting primarily hot and cold rolled steel 3/16" and lighter (but mostly 14 gauge and lighter). I am all about minimizing various stocked consumables. Why would I not use strictly fine cut consumables?
5- In the hypertherm manual under fine cut consumables item shield # 120979 and shield # 220325 are listed but # 220325 is for CE systems. Hmmm, what is a CE system?

1. The FineCut consumables are a takeoff from our high end high definition class industrial plasma systems...they are patented and only available for Hypertherm Powermax systems. They are designed for cutting 3/16" and thinner, at power levels under 40 Amps......these consumables produce a higher energy density arc as compared to the standard consumables...meaning less kerf width, a stiffer arc for less edge angularity.
2. Corner acceleration setting....a higher number will help minimize the start stop ding/divit caused by the lead in kerf. If the number for corner acceleration is too high...the machine will have jerky motion, too low.....and you will seee sluggish performance in corners. On my PlasmaCam...I found the factory default setting is perfect. It is set at .1G on my machine.
3. Slower on circles under (inch).....I have this set at 1.25" on my machine.....the machine will automatically slow down on circles under the preset size....this helps to eliminate the taper that is normally evident in small diameter holes due to the lag in the plasma arc. Some plasma system lag less than others....however I think 1.25 is a good number for this setting for most applications.
4. The cut speed for Fine Cut consumables will be slower than the cut speed for the 60 and 80 Amp consumables. The cut quality in terms of edge squareness and small feature quality will be superior. Do you need parts fast with more edge taper or do you want better quality parts slower? I also find that the Fine Cut parts do not last as long as the standard parts....I guess that is the price of having better cut quality!
5. You need to look at the Fine cut consumables as used for mechanized cutting in your manual.....and yes, they will fit on your hand torch. The PlasmaCam has an Ohmic contact function.....there is a wire that needs to make electrical contact to the shield on the front of the torch in order to use this valuable method of finding the surface of the plate before every cut. You must use the 220404 shield and the 220061 retaining cap with the Fine Cut parts to make this function work. That retaining cap must also be used with all of the standard shielded parts for cutting at higher power levels...and , you should use the machine shields for machine cutting. The hand shields are for drag cutting with a hand torch. The 120930 shield works for the shielded 40, 60 and 80 amp consumable sets in conjunction with the 061 ohmic retaining cap.

Hope this helps!

Jim colt

[noplacetosail]

You are truly a wealth of information, thanks so much.
We dont need perfect cut quality and want to save money. I am thinking of going exclusively with the 40 amp mechanized shielded consumables since 3/16 is the thickest we will be cutting and most of the time we will be cutting thinner gauged materials.

Does that sound wise?

Now, I see there are 40 amp mechanized shielded consumables and 40 amp mechanized UNshielded consumables. What are the pros and cons involved?

Thanks again!

[jimcolt]

The pros and cons of shielded vs unshielded consumables....

Unshielded consumables for air plasma cutting are old technology.....cut quality is no better than todays shielded parts...and consumable life is much worse. Hypertherm offers the unshielded consumables as they are used in some applications where clearance on 3 dimensional parts is better with the shape of the unshielded nozzle.....such as automated (robotic or other fixtures) cutting of pipe saddles, trimming stamping/forming flash, hard to reach areas on castings, etc. If a shielded nozzle contacts the workpiece at amperages over 40 Amps....the nozzle will be damaged....cosequently, shielded parts can drag on the plate all day without double arcing damage.

You say you are going to use the 40 Amp shielded parts since all of your cutting is under 3/16"? I would steer you to using the FineCut parts.....slightly slower cut speeds but dramatically better cut quality. Try them both...let the cut quality speed equation make the decision for you....my money is o the FineCuts!

Jim

[noplacetosail]

Ok you talked me into it I have ordered the fine cut consumables

120926 electrode
223029 nozzle
220404 shield
220061 ohmic retaining cap

[mdwalker]

Here is a MicroSoft Word form I made to record my settings in PlasmaCam. I just print off several copies then when adjusting settings for a specific material I record the settings then file the form in a notebook that I keep by my computer. It helps to track changes that you make to your settings and it also makes a nice backup for your settings if your computer crashes. I'm not familiar with other cutting software but the form may be adaptable to other software.

Danny

[noplacetosail]

Wow that chart is amazing !
I wish I knew what all that means!
Much to learn!

What machine do you have mdwalker?

[noplacetosail]

Ok, I have to ask this question

if a person had the same machine (hypertherm 1250 and a plasmacam) and used the same tips (fine cut) and used the reccomended amp settings and cut height then they could fill that chart out for the different thicknesses of mild steel and anyone could use it?

is that true?

[srp]

Remind me of a great cook. Others may use the same recipes and utensils but one who has developed the "art " - Ah - There is no comparison. With time and good practices good cut quality will come.

[mdwalker]

I have a PlasmaCam DH2 with a Hypertherm Powermax 1000. Consider your cutting system to be like a gasoline engine. You can take ten of the same engine, set them up identical and get them to start, but each one has to be fine tuned for optimal performance. This sheet is handy for making those fine tuning adjustments once you get your machine set up to cut a particular material. The most important thing I have learned is to pay attention to the small details that you don't think matters, because they do. Cut height, cut speed, clean air, quality material, new or good condition consumables have to be right, "almost right" or "close enough" doesn't cut it. Also when dialing in your settings you have to start with the basics first. Make sure your air is clean, your consumables are in good condition, and the basic functions of your machine and table are working correctly otherwise you are wasting your time trying to make the fine adjustments. Once you get the basics taken care of sacrifice a piece of metal and make lots of test cuts. Adjust your settings one at a time so you know what is making a difference. Another important thing I have learned is to read the cuts. Learn to read the kerf to tell if your cutting too fast or too slow and pay attention to what type of dross you are getting, high speed dross or low speed dross. I have only used PlasmaCam and Hypertherm so I am not familiar with other systems but you need to learn what each setting does on your system and how they relate to cut quality. You can learn alot from a book but nothing takes the place of time and experience. I have been involved in metal fabrication for almost 20 years, had a plasma cutter for about 12 years (started with Hypertherm Powermax 800 which I still use), and a cnc table for 2 years this coming Jauary, and I still learn something new almost every day. Just don't get discouraged. Tip: To set cut height go to your local auto parts store and get a set of feeler guages, like spark plug gap guages (the thin metal strip kind, not the round ones), start a test cut on a straight line and stop the cut halfway through and measure the distance between the tip and material, then make your adjustments.

Danny

[noplacetosail]

Thanks so much for the replies. Dear Jim Colt and mdwalker I have to ask would it be possible to purchase the configurations you have? Teaching 125 kids makes my time more than stretched and I would gladly pay for starting places for different gauges of material! I must admit as an educator I am pleased with the hyperthem and pleased with the plasmacam but less than pleased with the hypertherm parellel port cable hookup and training materials for training multiple users. I am also amazed I cant select a plasma cutter and material gauge in the software and it give me starting configurations. As an educator I am amazed plasmacam has not embraced these much needed changes. Anyways I will repeat my plea.

I have to ask would it be possible to purchase the configurations you have? The starting places would be a godsend!

[mdwalker]

I wouldn't be interested in selling you my settings but I will gladly give you what I have. It will take me a little time to get it together for you. I can't imagine trying to teach a class on cnc plasma cutting while trying to learn it myself. I would recommend taking some time during the holidays when school is out to go in and spend lots of time "playing" with the machine and learning as much as possible. I will be glad to help all I can.

Danny

[noplacetosail]

I will be the first to admit that I am one small step ahead of my students!
I would greatly appreciate any assistance I can get!
We primarily cut steel (hot and cold rolled) between 20 gauge and 3/16"
We use exclusively finecut tips on our hypertherm (per jim colts suggestion)

I will do my best to repay your assistance!

thanks so much! Don

[trump9721]

Remind me of a great cook. Others may use the same recipes and utensils but one who has developed the "art " - Ah - There is no comparison. With time and good practices good cut quality will come.