A bit of reality time for me.
The cut40 is never, never going to compete with the likes of Hypertherm, TecArc, Lincoln Electric and the other systems costing close to a few thousand pounds just for the cutter. I am always going to have issues with the machine!
So stop trying to get it infinitely better, figure out what it can do and get on with it.
I have to figure the limits of the machine, what it can, and can not do? Trying to find information on capabilities is hard. Found a guide for a Versa cut 40 machine on line and it said these are 20 Amps up to 5mm, 30Amps over 5mm up to 7.5mm and 40 Amps from 8 to 9.5mm (was actually all Imperial) It goes on to say the speed is typically from 10 inches per minute (250 mm per min) as that is what a person can do smoothly. So that sort of gives me a ball park idea.
So today I had a play at just running 200mm cuts in some Hot rolled Mild steel sheet, the gauge said it was 3.8mm.
I decided to run at 20 Amps starting off at 600mm per minute and the cutter would not hold pierce through the metal at this rate, so I had to go up to 30 Amps, this time no problem.
I also tried a few voltages on the THC controller, I dropped it to 88.5Volts (87 to 90 Volts) and it constantly ran on the metal, so I lifted back up to the 94.5Volt range (93 to 96 Volts) to get the Tip off the metal.
I started at 600mm per min and went up 700, 800, 900, 1000, and 1100 mm per min. At 1100 mm per min the arc would not hold pierce and spewed metal back against the tip and generally across the sheet. From the top of the sheet 600 to 1000 speeds looked OK, I suspect my torch is not perfectly square, but close.
Here is a picture of the top of the cuts.
The true story is on the back side of the sheet.
This is prior to removing any dross, it all came off easy, I could slide a chipping hammer across the back and all would chip away, easily. It does tell me I will not get rid of the hassle of removing it from the back side of anything I do, but 900 mm per min was the least to remove on this test.
Next I ran a flat flap disc over the back side to determine what the cut slots looked like without being hidden and we have this final picture.
Again to my mind 900mm looks the better cut to me at least, so I have a base setting for one thickness.
I also noted from the Mach3 screen how high the torch was running when set at the voltages above and we have
600mm 1.4 to 1.7mm Average 1.55mm
700mm 0.7 to 0.9mm Average 0.8mm
800mm 0.4 to 0.7mm Average 0.6mm
900mm 0.4 to 0.5mm Average 0.45mm
1000mm 0.4mm, not a lot of variance at all.
1100mm ran at 2.2mm above the metal when not piercing through.
All pictures can be made full size to view if you wish to view them better.
I am wondering if plasma cutting is like other metal removal processes, the best results for 3.8mm thick plate 1 mm cut width is removing 3,420 mm3 per minute, so if I do thinner if it is a linear relationship, do 1.4mm and double the speed, do 7.6mm thick and half the speed?
I need metal of different gauges to try.
Sorry for the long rambling post.
Adrian
The cut40 is never, never going to compete with the likes of Hypertherm, TecArc, Lincoln Electric and the other systems costing close to a few thousand pounds just for the cutter. I am always going to have issues with the machine!
So stop trying to get it infinitely better, figure out what it can do and get on with it.
- It is a cheap machine, sub £200 so I must put up with it.
- It is close, or over the rating of the mains outlet it runs on, but as yet not popped the 13Amp fuse.
- It has a Max 60% duty cycle at 40 Amps, (30.8Amps @ 100% ?) So keep at or under 30Amps.
- The torch & consumables are basic, and cheap by that I do not mean cost I can mean quality depending on where you buy them. But cost has a lot to do with it.
- They are designed as drag only machines and as such they have the simplest of interfaces, the only two variables is air post flow and Amps.
I have to figure the limits of the machine, what it can, and can not do? Trying to find information on capabilities is hard. Found a guide for a Versa cut 40 machine on line and it said these are 20 Amps up to 5mm, 30Amps over 5mm up to 7.5mm and 40 Amps from 8 to 9.5mm (was actually all Imperial) It goes on to say the speed is typically from 10 inches per minute (250 mm per min) as that is what a person can do smoothly. So that sort of gives me a ball park idea.
So today I had a play at just running 200mm cuts in some Hot rolled Mild steel sheet, the gauge said it was 3.8mm.
I decided to run at 20 Amps starting off at 600mm per minute and the cutter would not hold pierce through the metal at this rate, so I had to go up to 30 Amps, this time no problem.
I also tried a few voltages on the THC controller, I dropped it to 88.5Volts (87 to 90 Volts) and it constantly ran on the metal, so I lifted back up to the 94.5Volt range (93 to 96 Volts) to get the Tip off the metal.
I started at 600mm per min and went up 700, 800, 900, 1000, and 1100 mm per min. At 1100 mm per min the arc would not hold pierce and spewed metal back against the tip and generally across the sheet. From the top of the sheet 600 to 1000 speeds looked OK, I suspect my torch is not perfectly square, but close.
Here is a picture of the top of the cuts.
The true story is on the back side of the sheet.
This is prior to removing any dross, it all came off easy, I could slide a chipping hammer across the back and all would chip away, easily. It does tell me I will not get rid of the hassle of removing it from the back side of anything I do, but 900 mm per min was the least to remove on this test.
Next I ran a flat flap disc over the back side to determine what the cut slots looked like without being hidden and we have this final picture.
Again to my mind 900mm looks the better cut to me at least, so I have a base setting for one thickness.
I also noted from the Mach3 screen how high the torch was running when set at the voltages above and we have
600mm 1.4 to 1.7mm Average 1.55mm
700mm 0.7 to 0.9mm Average 0.8mm
800mm 0.4 to 0.7mm Average 0.6mm
900mm 0.4 to 0.5mm Average 0.45mm
1000mm 0.4mm, not a lot of variance at all.
1100mm ran at 2.2mm above the metal when not piercing through.
All pictures can be made full size to view if you wish to view them better.
I am wondering if plasma cutting is like other metal removal processes, the best results for 3.8mm thick plate 1 mm cut width is removing 3,420 mm3 per minute, so if I do thinner if it is a linear relationship, do 1.4mm and double the speed, do 7.6mm thick and half the speed?
I need metal of different gauges to try.
Sorry for the long rambling post.
Adrian