Benbox Laser Machines/CO2 Lasers/3D Printers

Kit Assembly => Spare Parts Sources => Topic started by: crazeuk on June 14, 2019, 04:36:01 AM

Title: Laser head
Post by: crazeuk on June 14, 2019, 04:36:01 AM
Hey guys. I bought a 1.5 watt Qiilu laser Engraver on a whim, just to play with. I have really enjoyed it.

So decided I want something bigger.
I was going to buy one of those k40 machines, but happy to wait until a cheap one comes up.

A few days ago, I bought a brand new vigotec VG-L3 kit. Mainly because I wanted just to build something (adults mechano set).

Anyway, I know I can get a 5.5W laser for it, but for the same price, I can get a 450nm 15W laser off Ebay.

So, should I just look at paying the 90 for the 15W.

What is the best source for laser heads?
Can I buy acrylic "filter sheets for around the laser head (don't want to risk people's eyes).


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Title: Re: Laser head
Post by: Zax on June 14, 2019, 05:26:37 AM
In my opinion a "cheap" 15W laser from ebay is a waste of money. It is most likely a 6W diode over driven and "pulsed" to output double it's design limit, this makes it useless for cutting and it will have a very short lifetime. They also have a large spot size and possible a non-circular one which makes it very poor for engraving.

There are exceptions such as the Endurance lasers but they're expensive.

The CO2 option is much better in most cases although it depends on the materials you plan to engrave / cut.

Yes you can make an enclosure using suitable acrylic (you want OD4 or higher at 450nm for the diode lasers which isn't cheap), or use solid panels and a viewing window of acrylic to keep costs down. CO2 laser wavelength (near-IR) is much easier to block, almost any acrylic will work however being invisible it's also potentially more dangerous to your eyes (and home).
Title: Re: Laser head
Post by: crazeuk on June 14, 2019, 05:41:42 AM
Hey Zax.
Thanks for the quick reply.

The one I was looking at is https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F333198515764 (https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F333198515764)

I thought this maybe the case.

To be honest my use would be hobby and varied.

Mainly I wanted to engrave personalised gifts.
However, if I can cut, I will!! - although I also have a CNC machine.

Are the 40W Co2 lasers any good? I read their tubes are cheap and burn out quick!!


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Title: Re: Laser head
Post by: Zax on June 14, 2019, 06:22:15 AM
I love their ad, it can work for a long time... then, after 30 minutes leave to cool down.

If your primary use is engraving, get a good quality 2.5W or even 1.6W laser module. The EleksMaker modules are some of the best low power modules I have found.

Yes, the CO2 (K40) lasers are very good in my opinion but they do require a bit more maintenance. My tube lasted ~6 years (it was still outputting nearly 30W, it was 36W when new so had lost less than 20%) because I never ran it at 100% power and added important features like a flow rate switch and thermal cut out, these saved my tube on several occasions when the cheap pumps failed.

I prefer the diode lasers for grey scale and long engraving jobs and the CO2 for cutting and deeper line engraving. Each tool has it's purpose, just like anything.
Title: Re: Laser head
Post by: crazeuk on June 14, 2019, 06:28:07 AM
Thanks again :D

I'll look into that.

I do really want a co2 laser, only problem is storage of everything lol.

I should just make my own hacker space. Lol

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Title: Re: Laser head
Post by: ggallant571 on June 14, 2019, 05:42:26 PM
I bought one of those about a year ago. Fired it up last month and suspect it is more like 3W. There is an adjustment on the electronics board which seems to have an effect on the amount of current consumed but the lack of documentation makes me leary to fiddle with it. On the plus side, it has a great sharp focus. I asked and received no reply as to the recommended use time. So far the heat sink stays cool.
Title: Re: Laser head
Post by: crazeuk on June 14, 2019, 06:06:11 PM
I bought one of those about a year ago. Fired it up last month and suspect it is more like 3W. There is an adjustment on the electronics board which seems to have an effect on the amount of current consumed but the lack of documentation makes me leary to fiddle with it. On the plus side, it has a great sharp focus. I asked and received no reply as to the recommended use time. So far the heat sink stays cool.
Do you mean a 15W diode head?
Not selling it are you? Lol

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Title: Re: Laser head
Post by: ggallant571 on June 14, 2019, 08:09:26 PM
It is supposedly a 15W diode. The ebay entry is no longer available but looks like:

https://www.ebay.com/itm/15W-Laser-Head-Engraving-Module-with-TTL-450nm-Blu-ray-Wood-Marking-Cutting-Tool-/352691706357?oid=332486735606

As Zax said, a quality 1.6 or 2.5 module will outperform this grossly exaggerated POS for etching. I have yet to see it outperform the 2.5 for cutting. Perhaps playing with the adjustment will do something.

The power module that came with it is a Chinese 5A, 12V or 60W supply. Assuming a 15% output to input power efficiency we would need a 100W supply to power the critter.  Next time I use it I will hookup a 10A supply and a current meter.

I did not see any significant voltage drop while testing with the 5A supply.
Title: Re: Laser head
Post by: crazeuk on June 23, 2019, 06:02:41 AM
Hi. Thanks for the responses.
I found someone selling a 15w head and supply privately, from a project he never completed. So bought it, to play with while I search for a k40 (need to keep costs low).

I'll sell this once I get a k40, although I like that it is portable.

I have a question:
The Vigotec VG-L3 frame I have, comes with a control board.
In the manuals, it mentions up to a 5.5w laser.

Does this mean, if I connect the 15W head with a TTL cable, it will only give out 5w of power?

If so, how do I run power direct to the laser with the included adapter, and still use the TTL function.

I've tested the laser, everything works well, but I don't feel it's doing a any where near 15w  job (I read the above comments, and understand about the quality, so not expecting that.) - I just want to see if the control board is throttling its potential.

Thanks

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Title: Re: Laser head
Post by: crazeuk on June 23, 2019, 06:07:24 AM
This is one of my burns I am doing.
P.s. I think it's being throttled as the heat sink case isn't even getting warm. - even without the fan I am using near it to circulate air.(https://uploads.tapatalk-cdn.com/20190623/0881d4d87e09e45fa50d3c0afea1059e.jpg)(https://uploads.tapatalk-cdn.com/20190623/6d57550e72e12688e3d1819603141304.jpg)

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Title: Re: Laser head
Post by: ggallant571 on June 23, 2019, 06:51:41 AM
Welcome to Chinese specmanship!! Perhaps the 15W is the bulk power consumption. That would equate to a 1.5W diode and work fine with the included power supply.
Title: Re: Laser head
Post by: Zax on June 23, 2019, 08:21:46 AM
They aren't quite that inefficient, at 15W it should be just over 3W.
Title: Re: Laser head
Post by: crazeuk on June 23, 2019, 09:04:41 AM
Wow. I 5 fold inefficiency?
Outside of a laser meter (does anyone have one). Is there any way to measure the output from the controller and driver?

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Title: Re: Laser head
Post by: Zax on June 23, 2019, 11:41:32 AM
I have a laser power meter but typically stop at 8W which is 5.0~5.5A depending on diode so it's not quite that bad but 0.28~0.35 efficiency is typical.
Title: Re: Laser head
Post by: crazeuk on June 24, 2019, 11:33:57 AM
Oh you do do you

Where do you live again? I may have to make a trip lol.

I am really curious about what power this gives out, and to see if the control board is limiting it.

(https://uploads.tapatalk-cdn.com/20190624/be2b63442e328510eeab2ba78028ad12.jpg)(https://uploads.tapatalk-cdn.com/20190624/360771a31a128d9eacd4a4f0c98e94da.jpg)

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(https://uploads.tapatalk-cdn.com/20190624/263a0048cf314968b12a93427bfd73ad.jpg)
Title: Re: Laser head
Post by: Zax on June 24, 2019, 11:43:54 AM
Either you have really big hands or that's a tiny laser module  :o

There's no way that heat sink would work for 15W, take a look at the Endurance Laser modules http://endurancelasers.com/endurance-10w-laser/
Title: Re: Laser head
Post by: crazeuk on June 24, 2019, 12:46:49 PM
Lol. Bit of both maybe. The laser it self is 30 x 30 x    75 mm. The control power supply for it is the black heat sink (blue board).

My hand is 120 x 200 x 30mm and displaces 500ml.


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Title: Re: Laser head
Post by: ggallant571 on June 24, 2019, 03:46:35 PM
Do you have an oscope or logic analyzer?

From an ad on Aliexpress:

Parameter:
Wavelength: 450NM
laser power: impulse=15W, average 6-7w output.
Voltage: DC 12v 6a
TTL frequency=0v on 5v off; less 50k
LD currect input:2-2.5a
Title: Re: Laser head
Post by: crazeuk on June 24, 2019, 04:18:00 PM
Nope, what are they?

Ya I figured it Maybe lower, then maybe they over drive in pulses.

I don't feel like I am even getting 5W.

Also, I noticed the power driver says 5W in the model number. You can see it in the pic.

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Title: Re: Laser head
Post by: crazeuk on June 24, 2019, 04:19:03 PM
Oh oscilloscope? Lol no.

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Title: Re: Laser head
Post by: ggallant571 on June 24, 2019, 04:41:15 PM
I also have a "15W" and suspect it is a 3W because it draws about 3A at full on and the burn is similar to some other "known" 2.5W units.

You can purchase low frequency USB oscilloscope and logic analyzers quite cheaply. Good enough to measure most Arduino generated signals.
Title: Re: Laser head
Post by: crazeuk on July 27, 2019, 05:11:27 AM
Hey guys.

An update..
So I contacted the seller to return the head.

They checked with their supplier who said it was in fact 2300mw - Although I suspect they knowingly sold it hoping people would not realise.

Just for the sake of it (to give the frame purpose), I purchased a 5.5w head (fleabay (http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=202665419328&category=46742&pm=1&ds=0&t=1558432075000&ver=0)).

Here are pics comparing the two:
Original 15W (2300mw) Left - Replacement 5500mw Right
(http://benboxlaser.us/index.php?action=dlattach;topic=3702.0;attach=14104)

Original 15W (2300mw) Left - Replacement 5500mw Right
(http://benboxlaser.us/index.php?action=dlattach;topic=3702.0;attach=14106)

Original 15W (2300mw) Left - Replacement 5500mw Right
(http://benboxlaser.us/index.php?action=dlattach;topic=3702.0;attach=14108)

The VigoTec VG-L3 frame driver board.
(http://benboxlaser.us/index.php?action=dlattach;topic=3702.0;attach=14100)

The laser driver module. - Notice it doesn't have a connector for the PWM / Pwr / Laser slot on the above driver.
(http://benboxlaser.us/index.php?action=dlattach;topic=3702.0;attach=14102)

My Problem is when I connect the Laser driver module to the Frame driver board, i via Laser (on the frame driver board) - I do not think there is any power getting to the laser (the fan doesn't turn on, nor does the low power laser).

Title: Re: Laser head
Post by: Zax on July 27, 2019, 07:27:57 AM
You have a separate power supply for the laser driver board, correct?

You have the TTL input connected to the controller board, correct?

I guess seeing your final wiring would be helpful but typically the fan runs when power is on whether or not the laser is on.
Title: Re: Laser head
Post by: crazeuk on July 27, 2019, 08:39:23 AM
You have a separate power supply for the laser driver board, correct?

You have the TTL input connected to the controller board, correct?

I guess seeing your final wiring would be helpful but typically the fan runs when power is on whether or not the laser is on.
Thanks for the response.
The laser didn't come with it.

I did notice the polarity of the white and yellow cable from the frame driver to laser driver was replaced.

I've swapped the wires on the connectors, and it works.

My new question is what is ttl, Ttl+, Pwm and analogue. - which it better to use?

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Title: Re: Laser head
Post by: Zax on July 27, 2019, 11:05:56 AM
TTL designates the voltage levels (logic) which in this case is 5VDC.
PWM is pulse width modulation a method of switching the voltage.

In most cases the Chinese use these interchangeably although they are very different, so when it says TTL it means a TTL/PWM and when it says PWM it means the same. You could have PWM at 12VDC (e.g. the MOSFET output) or TTL without any PWM, just on and off logic.

Analog would refer to a variable input voltage, probably 0 to 12VDC which is translated to a TTL/PWM output. I haven't seen this very often but if you had a simple potentiometer you could use that to control laser power manually.

It's not really a question of "better" but what you have available, since the Nano output is TTL with 8-bit PWM that's "best" in this case.
Title: Re: Laser head
Post by: crazeuk on July 27, 2019, 11:24:38 AM
TTL designates the voltage levels (logic) which in this case is 5VDC.
PWM is pulse width modulation a method of switching the voltage.

In most cases the Chinese use these interchangeably although they are very different, so when it says TTL it means a TTL/PWM and when it says PWM it means the same. You could have PWM at 12VDC (e.g. the MOSFET output) or TTL without any PWM, just on and off logic.

Analog would refer to a variable input voltage, probably 0 to 12VDC which is translated to a TTL/PWM output. I haven't seen this very often but if you had a simple potentiometer you could use that to control laser power manually.

It's not really a question of "better" but what you have available, since the Nano output is TTL with 8-bit PWM that's "best" in this case.
Great. Thank you for the explanation.
That laser driver has a analogue input (blue connector) and a switch to switch between the two.


What I was amazed at between the two heads is the lower power one has a much bigger driver set in an aluminium heatsink box with a fan.

The 5500mw driver it's much smaller, in a plastic case. No fan.

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Title: Re: Laser head
Post by: ggallant571 on July 27, 2019, 05:33:15 PM
Diode lasers are about 15% efficient. For a 5.5W module you need to supply about 36W (12V, 3.0A) of raw power. The other 85% is dissipated as heat . Some vendors do a better job than others at reliably handling this heat. They all work for the first 2 minutes, you want one that will work for 2 days.