Laser Comparison – Cutting Speed And Rate of Feed

[Final installment in a series of three articles comparing metal-cutting lasers.]

In two previous articles we examined the differences in electrical costs and resonator operating costs between the various types of metal fabrication lasers.
We can recap the previous articles by looking at chart #1 below. It shows the operating cost over 8 years for a 4kW laser.

Chart 1
We can also see by chart #2 the actual differences of energy consumption for solid state lasers.

Chart 2
The differences in the operating cost are based on the maintenance and the efficiency of the style of laser being used. Chart #3 illustrates the different efficiencies for the various cutting lasers.

Chart 3
The final piece of the puzzle for laser processing is the cutting speed. Approximately 80% of the time while the program is running the laser is cutting, this is the majority of the processing time. The cutting capabilities of the laser is directly proportional to the beam quality and beam waste of the laser. Chart #4 illustrates the characteristics for the four cutting lasers.

Chart 4
Things to be aware of are the mode quality, beam waste, spot size, and depth of field. The depth of field generated by the laser will affect the cut quality and the thickness of the materials processed. The depth of field is the usable portion of the unfocused beam. This occurs on both sides if the beam waste (smallest spot size). As the focal position is shifted up and down to enhance cutting the operator must always keep the material within the depth of field or the material will stop cutting.

Finally I would like to share some comparative cutting charts to show the difference in feedrates for the CO2, Disk, and Fiber lasers.

STEEL (USING O2)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Steel	0.040	1.0	280	340	319
O2	0.060	1.5	210	252	260
	0.080	2.0	170	200	224
	0.100	2.5	130	173	173
	0.120	3.0	120	150	151
	0.180	4.5	110	130	132
	0.250	6.4	100	110	110
	0.375	9.5	70	75	85
	0.500	12.7	56	52	60
	0.625	16.0	38	41	45
	0.750	20.0	32	30	33

STEEL (USING N2)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Steel	0.040	1.0	360	1682	2362
N2	0.060	1.5	260	1186	1417
	0.080	2.0	200	910	760
	0.100	2.5	170	500	550
	0.120	3.0	140	374	380
	0.180	4.5	80	200	213
	0.250	6.4	50	89	95

STEEL (USING AIR)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Steel	0.040	1.0	720		2126
Air	0.060	1.5	470		1417
	0.080	2.0	350		756
	0.100	2.5			472

STAINLESS STEEL (N2)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Stainless	0.040	1.0	400	1682	2362
Steel	0.060	1.5	290	1160	1654
N2	0.080	2.0	230	886	886
	0.100	2.5	195	610	610
	0.120	3.0	160	334	354
	0.180	4.5	100	177	197
	0.250	6.4	80	120	138
	0.375	9.5	28	25	59
	0.500	12.7	16	16	39
	0.625	16.0	14	12	28

ALUMINUM (N2)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Aluminum	0.040	1.0	420	845	2126
N2	0.060	1.5	320	501	1417
	0.080	2.0	260	354	756
	0.100	2.5	215	265	425
	0.120	3.0	170	177	402
	0.180	4.5	60	132	170
	0.250	6.4	40	92	100
	0.375	9.5	10	40	45
	0.500	12.7		20	21

ALUMINUM (AIR)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Aluminum	0.040	1.0	460	2165	2165
Air	0.060	1.5	300	1219	1417
	0.080	2.0	210	680	756

COPPER (O2)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Copper	0.040	1.0	N/A	765	1701
O2	0.060	1.5	N/A	472	898
	0.080	2.0	N/A	315	591
	0.100	2.5	N/A	215	378
	0.120	3.0	N/A	115	236
	0.180	4.5	N/A	47	113
	0.200	5.0	N/A	35	80

BRASS (N2)

*MATERIAL*		*FEEDRATES*
			CO2	Disk	Fiber
	inch	mm	4.0Kw	4.0kW	4.0kW
			in/min	in/min	in/min
Brass	0.040	1.0	N/A	787	2126
N2	0.060	1.5	N/A	472	1063
	0.080	2.0	N/A	335	591
	0.100	2.5	N/A	242	378
	0.120	3.0	N/A	150	236
	0.180	4.5	N/A	80	106
	0.250	6.4	N/A	42	42