Dual head lasers What is their selling point?

[Mike Lysov]

Hi guys,

the question is within the topic title. I just do not get it. To get a beam to a second head you need to split it so each head can get roughly 50% of a tube power. Actually it will be less than 50% because of all mirrors that are not 100% effective. Then you are loosing a bit of power on a second head because of its mirror.

How can anyone be convinced it doubles machine production?

And yet a lot of laser makers make them claiming it and customers are falling for it.

[Rich Harman]

The dual head machines that I have seen also have dual tubes, each with its own set of mirrors to steer the beam to the laser head.

[Dave Sheldrake]

Up to quad head usually have multiple tubes as Rich said, after that they go to beam splitters or partial mirrors

[Kev Williams]

My Triumph is a dual-head machine, it has the brackets for the second tube, the mirror mounts, even the second mV meter is installed, I just need a duplicate set of optics and a tube and I'm good to go. With a 51" wide working area you can split into two 25" working areas, it can make sense depending on the jobs you do.

I don't need or want a second cutting head because you're locked into a 25" max width work space, no more cutting up full sheets of Rowmark :)

[Matt McCoy]

I don't need or want a second cutting head because you're locked into a 25" max width work space, no more cutting up full sheets of Rowmark :)

Could one laser head still be used on oversize jobs?

Would the second head resume cutting outside of the first head's zone, on large pieces?

If making lots of small parts, each zone would cut duplicate pieces within its envelope, still utilizing full sheets of material -- right?

Thanks.

[Martin James]

one of the heads is fixed. each end of the drive belt is attached to the head bracket. The other head is screw crimped onto the belt. You can move that head. Most people use the dual to cut 2 pieces at one time. They have the bed size width in the user settings set at about half the actual table size. one tube fires to the right and the other to the left. The actual machine is only about 10 inches wider than the one tube model.

My machine is dual tubes bet one is a 60 and the other 150. I have both heads as close together as possible to give me the most table space. In the software i have to select which tube i want to use for the job.

My laser has 2 heads, 2 tubes 2x mirrors, 2x power supply,2x dials, 2x stop switches. 2x the other electric box that I don't remember what it does and 2 cooling in outs. the cooler is the 5300 seres which has alarms on both in outs. Plan on spending about $700 extra machine plus tube. same footprint.

M

[Kev Williams]

Yes- suppose you're using 49" long Rowmark and need a whole sheet cut into 1x3 pieces, you have enough material plus you can split the extra inch 3 ways to give you a .333" margin space at the edges and in the middle, plenty spare space. You now cut 2 identical halves at once, cutting your work time in half... THAT is the selling point! Odd piece cuts should be able to be seamed together smoothly, where laser2 starts where laser1 leaves off...

My issue is how smoothly the seams would be joining text and graphics together. Because both halves would be different there's no time savings, but IF the 2 lasers are properly aligned, could work!

[Mike Lysov]

I have not thought of two tubes but it is still does not make any sense.

Why not to go with 2-2.5 times more power of a tube and use one head machine only?

However it does make sense for cutting something thin like fabric or etching on something soft where you do not need too much power or cutting with 20-40% of power but cannot increase a speed of cutting because of acceleration limit of machine motion system.

Also it does make sense where you need at least 100-180W per head to cut through at 80-90% of power as a single tube with 200-360W either does not exist or cost much more than two tubes with half of the total power each. If you need only 40-80W to cut through then a single tube with 2-2.5 more of required power and a single tube will give you the same result, let you use the whole bed and will cost cheaper.

[Scott Shepherd]

I have not thought of two tubes but it is still does not make any sense.

Why not to go with 2-2.5 times more power of a tube and use one head machine only?



Because power isn't the limited factor in engraving, speed is. For example, if you have a material that is running at 100% speed and 30% power, what's doubling the power going to do for you? Nothing. You need the extra speed until your power is at 100%, so it might take 400% speed (not possible) to engrave that material at 100% power. Using a dual head would double the production in most cases. If you had a material that used 100% power and 30% speed, then I'd agree with you, you need more power.

[Kev Williams]

If you had a material that used 100% power and 30% speed, then I'd agree with you, you need more power.

and even then, doubling power won't double your cutting speed. It's like making your stereo louder, twice the power won't make it twice as loud, for that you need 10x the power. Lasers are similar, but Sheldrake would know better than me the power/output ratios of these things! ;)

[Matt McCoy]

Good example Steve.


If you had a material that used 100% power and 30% speed, then I'd agree with you, you need more power.

and even then, doubling power won't double your cutting speed. It's like making your stereo louder, twice the power won't make it twice as loud, for that you need 10x the power. Lasers are similar, but Sheldrake would know better than me the power/output ratios of these things! ;)

Two heads cutting/engraving would double your productivity though.

[Dave Sheldrake]

If you had a material that used 100% power and 30% speed, then I'd agree with you, you need more power.

and even then, doubling power won't double your cutting speed. It's like making your stereo louder, twice the power won't make it twice as loud, for that you need 10x the power. Lasers are similar, but Sheldrake would know better than me the power/output ratios of these things! ;)

After a point they follow the inverse square law for cutting ability, my 7.5kW isn't 10 times faster than a 750 watt, it's about 4 times faster. The ability to cut thick materials reduces the thicker you get due to a huge number of factors not least as power increases so does head weight, my mitsu head weighs about 45kg's, you can't throw that around like a feather no matter how big you make the motors

[Dave Sheldrake]

Good example Steve.



Two heads cutting/engraving would double your productivity though.

Surprisingly it doesn't, it works about about 3-1 for productivity, if you want to double your workflow you need 3x as many cutting heads, I found at 4 machines / heads a worker is at the peak of production, after that it becomes too inefficient to bother with more machines.On the odd occasion I'm short staffed I turn machines off rather than try to spread people around to run more kit

[Martin James]

it is true that adding an extra head to your system adds extra weight, and therefore reduces the maximum speeds for a given job.

I use the 150 watt & 60 Watt combo because the 150 was the biggest tube that fits the machine and the 60 is the biggest that still has the smaller spot for much finer engraving.

When they list the specs for a tube highlight the "smallest character" and then compare that figure across the range of tube options. On most co2 tubes that I have seen the 60 gives the smallest character. With a smaller beam coming out of the end of the tube that hourglass shape of the beam where it leaves the head and goes down to the table and beyond is less pronounced than on the larger tube. therefore the depth of field is greater for a given lens than the tubes that have a larger beam coming out of the tube. The 60 only costs 200-300usd. the 150 was 1300-1500usd each.