[ImpactAxis]

Hi there folks, as promised some time ago, I have created a review of my experiences with a Chinese Laser Engraver. It is all detailed in an article on my website, and for anyone interested, the machine in question is a Jinan Derek 9060 80w CO2 Laser Engraver. You'll notice that the design of the machine is much the same as many other laser engravers on the market presently.

Anyhow, here is the link to the article.

Chinese Laser Engraver User Experience | Beyond Trophies

[ArtHeatSign]

A very great review you've written there about your new 80W CO2 Laser Engraver.

We’d both agree that CO2 lasers are most popular for their high efficiency and great beam quality.

You could check out my write-up on CO2 Laser Marker in the link below

https://www.heatsign.com/heatsigns-c...rking-machine/

[ledaero]

You mention the lower speed of the Chinese laser, but is this not a function of the material being cut and power of the laser?

An 80W Trotec cutting 10MM acrylic should run at the same speed as an equivalently-configured Jinan-made RECI-tubed unit, shouldn’t it?

Or does the Trotec 80W perform much better than a RECI 80W tube?

[ImpactAxis]

You mention the lower speed of the Chinese laser, but is this not a function of the material being cut and power of the laser?

An 80W Trotec cutting 10MM acrylic should run at the same speed as an equivalently-configured Jinan-made RECI-tubed unit, shouldn’t it?

Or does the Trotec 80W perform much better than a RECI 80W tube?

Hi there, unfortunately no. Chinese machines tend to be slower due to using stepper motors instead of servo motors (as is found on expensive machines). I'm no engineer or expert, but to my knowledge stepper motors can't move quickly beyond a certain point without creating problems, like loss of quality in what you are engraving.

I'm not sure how similar a Trotec 80w and a RECI 80w tube would be with cutting. Logically they should be of similar performance with something 10mm thick, as neither machine would be exceeding any speed thresholds whilst cutting (even the Chinese one with the stepper motor). 3mm and thinner material, and I could imagine the Trotec having the opportunity to run at faster speeds than a Chinese machine.

Engraving (marking) is a different matter altogether. The X-axis servo motor of Trotecs can run back and forth very vast without loss of quality, which is not the same for Chinese stepper motor X-axis, which generally don't like to be run past 400 - 500.

As far as engraving quality, my Chinese tube is well-aligned and my settings have been fine tuned, and the engraving quality is equal to that of Trotec machines I have used. It's just slower, due to the stepper motor restriction on speed.

- Grant

[ledaero]

Gotcha.

Not an engraver, so I suspect I will be limited by the cutting speed, not the steppers.

Smarter controllers using s-curve motion control improves speed on CNC using steppers. Not up to servo speeds, but significantly better than grbl, for example.

For what I want, using a smarter controller and not a Chinese DSP one might be worth the effort.

[Storen]

Chinese machines tend to be slower due to using stepper motors instead of servo motors

Not just the motors alone. The whole drive system will be slower. Replacing the steppers on a Chinese machine with servo motors (easily doable) wouldn't help much.

I'm not sure how similar a Trotec 80w and a RECI 80w tube would be with cutting. Logically they should be of similar performance

Well, both lasers use completely different technology. You should expect the difference in the performance to be quite substantial. An RF laser would perform better in any scenario.

[ledaero]

For the purposes of argument, the motion control system can be treated separately from the light-emitting system.

Having used tons of different motion-control controllers in my time, most of the issues I see with Chinese laser speed is down to the awful motion algorithms used.

Keeping all the wiring and drivers and steppers the same, but replace the controller with a 32 or 64 bit one with advanced kinematics can seriously improve speed while keeping vibration and overshoot in check.

Recently there have been some significant changes in controller firmware, where the motion-control is offloaded to an advanced processor for doing all the kinematic equations and the on-board controller just tells the steppers which direction and how high.

Another issue is non-optimised toolpath, where the head is no back over areas it’s previously been to and performing additional cuts - all wasted effort and additional time.

If you watch a Trotec at work, it doesn’t do this.

Of course an RF laser is going to perform better than a DC laser, but for what I want, which is cutting, it’s not 5x better - more like 20%.

Im going to buy a cheap K40 and play with tuning kinematic sand see how much of an improvement I can make.

[Storen]

To ledaero - I agree completely with everything you wrote. Just wanted to add - it is critically important to pair the motion-control system, with adequate mechanical drive components and enclosure structure. The servo systems use different actuators, designed to operate at higher speeds and more rigid housing structure reducing vibrations. That is why I suggested upgrading the motors alone (to servo) on a stepper system wouldn't help much.

I am not very experienced with the software side of the problem. Are all the Chinese controllers 32 bit?
Do you intend to upgrade some of the mechanical components and the controller on the K40 or just tweak it?

As for the DC vs RF sources - There is no general rule, it really depends on the application. There are products that require very high-quality cutting where the fluctuations of the DC lasers are not acceptable so the only option is using RF lasers. However, these cases are rare. Most of the time DC lasers are fine for low-speed cutting. The advantages of the RF technology really shine when engraving.

[Stewey]

Exactly- RF tubes can switch on and off far more rapidly, so can engrave accurately at far faster speeds than CO2 lasers with their high-voltage low current tubes and PSUs.

[ledaero]

Exactly- RF tubes can switch on and off far more rapidly, so can engrave accurately at far faster speeds than CO2 lasers with their high-voltage low current tubes and PSUs.

If you need any of that, I’m sure it’s a plus.

if you don’t, it’s a LOT more money than you need to spend.

My 150W Reci EATS 15mm plywood. What would an RF laser of the same price/performance ratio give me?