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Information needed before buying what I need

Posted by Ohmarinus 
Information needed before buying what I need
December 17, 2014 07:30AM
Hi guys, I have been looking at DIY lasercutters lately. I have build a CoreXY-frame planning to make yet another 3D-printer, but now I realize that it's better to turn it into a laser cutter for more versatility.

In another topic I've already found out some of the things I need. For example a 445nm laser.
Planning on getting this one:
[www.ebay.com]

Now, it doesn't come with anything else, so I would need to get a driver, I've found this one to be good:
[www.illumn.com]
However, it delivers 4W max and it's quite expensive compared to other drivers I've seen around. There must be a cheaper and more fitting solution.

I'm very much lost in the woods, as I have no idea why the Hz on a driver is important. Furthermore I want to use my Ramps that I had planned to use for the printer, to run the lasercutter now.

What I have:
- CoreXY frame ready to play
- Ramps 1.4 with SD Ramps and LCD
- 12v PSU with multiple power outputs

So, I guess what I will need:
- Laser Diode 2W inside a housing
[www.ebay.com]

- Driver board (TTL?)
[www.ebay.nl]
(what is the NTC needed for?)

- Heatsink + Active cooling + fan blowing away the smoke
[www.ebay.nl]

- Protective glasses - or with preference, protective encasing material
Haven't found for the 445nm range

What else am I missing here? Is the Ramps capable of sending the signal for the laser to the driver board as well?

I've been reading a lot, but it's very hard for me to find 'exact' information and most guides are a bit vague about the exact items needed to build a laser cutter. I see a lot of cheap lasercutters, but now that I'm looking into the parts, I see it isn't as cheap as advertised, the parts I've found will probably set me back another 150 euros, so I'm curious if I'm really finding the correct things.


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 17, 2014 08:23AM
... with the 2W-diode you'll need 1.7Amps max, so any >2A-driver would be OK ... but the cooler on your first driver link is much to small! ... either way, better 'oversize' your coolers for safety ... and the NTC/thermal protection is to shut down the driver, when the diode starts overheating (>30degC)

You'll need TTL when driving the diode with PWM, as analogue driving isn't trivial when dealing with acc-/decceleration at line-start/end and in curves. I'm driving all my lasers for engraving and sintering with pulses -- only for cutting analogue is better, when driving slow enough without acceleration ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 17, 2014 09:57AM
Aha, so TTL tells the laser to turn on and off at a certain speed. So, my guess would be that the driver converts the PWM-signal into on(5v) and off(0v) signals at a maximum speed of the specified Hertz the driver can support?

Basically I can set one of the Ramps pins up so that this sends the correct PWM signal to the driver? Curious if it will already work as-if by just using the D10 output.


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 17, 2014 10:25AM
... my actual drivers can handle clocking speeds of up to 500kHz (=> a pulse every 2 microseconds with 1 microsecond duration) for max. engraving speeds of 1,25m/s with a resolution of 0,0025mm ... but as my CNC-mill can only drive with 150mm/s, this is a bit 'overdefined' -- but I too have a servo-XY-scanner in the build, where I'm closing to 1m/s winking smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 17, 2014 02:35PM
Lots of good info at J Tech Photonics

See

[jtechphotonics.com]

and the blog

[jtechphotonics.com]

SAFETY
I have a set of the Jtech red glasses
and
a 16" x 16" red acrylic 9% transmission

Mostly I watch my laser via a webcam


confused smiley
Re: Information needed before buying what I need
December 20, 2014 09:38AM
Quote
VDX
... and the NTC/thermal protection is to shut down the driver, when the diode starts overheating (>30degC)
The diode should not be powered when its temperature is over 30C? If the ambient temperature is around 24C, you would only have 6C left until shutdown.


http://www.i3d.ro
VDX
Re: Information needed before buying what I need
December 20, 2014 07:16PM
... even if you'll cool down the diode housing to 30degC, the crystal can get several degs hotter -- and typical diodes starts degrading when over 30degC crystal temperature ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 21, 2014 04:10AM
Is it even possible to prevent it from going over 30C, when it is operating in a room with a 24C temperature? Maybe a Peltier pad attached to the heatsink.


http://www.i3d.ro
VDX
Re: Information needed before buying what I need
December 21, 2014 05:58PM
... yes, common 'safe' diode-modules are equipped with a Peltier cooler ... have some old pretty big (shoe-box size) 20W-modules with 14(!) Peltier elements and a gigantic cooler sitting under the module box eye popping smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 21, 2014 06:38PM
The thing is I never seen any of the common 2W diodes being sold with a Peltier. At most I saw them with some heatsink or maybe a heatsink and cooler on it. That is why I am amazed they would start degrading at only 30C. Even so, a torrid summer day exceeds 35C, that would mean they degrade without even cutting.


http://www.i3d.ro
VDX
Re: Information needed before buying what I need
December 21, 2014 08:02PM
... you can store them with temps up to 70degC without problems ... but if run, then the expected lifetime will shorten drastically, when heated above 30 degC eye rolling smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 22, 2014 07:55PM
After reading on, it seems that this is the kit I need:
[jtechphotonics.com]

I have gotten a bit of extra money from second-hand things I've sold this month and can afford to buy this laser. It will be $384.49 including tax. So I would have to calculate how much extra tax I would have to pay, it probably will be another 100$ for the Netherlands... Hmm, maybe I have to find another product... I realize this is getting very expensive.

It will cost me €409 euros, this is $500 USD. Hehe, okay, nevermind, I will forget about this.

Can I directly run this laser through my Ramps 1.4 or do I need to buy additional parts? I've seen Cozmicray's lasercutter and he seems to use the 1.7W version, so I would assume that I can use this 2.8W laser with the same setup as Cozmicray.

The 1.7W version will cost me 306 euros, or 375 dollars.

Edited 4 time(s). Last edit at 12/22/2014 08:03PM by Ohmarinus.


http://www.marinusdebeer.nl/
Re: Information needed before buying what I need
December 22, 2014 08:42PM
That is why I opened the other thread regarding seeing the diodes in action. It's a lot of money, considering it gets close to a small CO2 laser and it should help seeing some cuts before spending.

The price is probably ok for the US, but once you add the shipping cost and custom fees, it stacks up pretty high. Diodes are kinda limited in materials they cut, so it would probably be harder to recover some of the invested money by offering a cutting service, at least compared to a CO2. Either way, I hope you get the 2.8W so we can see what it can cut.

jtech has a user around here I think, probably he will provide more details about the RAMPS connection.


http://www.i3d.ro
Re: Information needed before buying what I need
December 22, 2014 09:35PM
Run it thru RAMPs
?? 12V supply out of D8, 9, 10 ?
I don't think it will like PWM input?

Normally 12V is turned on then 3-12V logic level applied to trigger port
to light off the laser

No G-code for laser ON/OFF

I use micro switch to trigger mine ON with Z down

2.5A driver should be good to drive 2.8W diode

$$$ The Jtech 2.8W kit (diode, driver, red glasses) is $335
$165 for shipping and tax to Netherlands ??? Thats' worse than Obama tax

??? Where can you buy a CO2 laser rig (with optics, mirrors) for $335???

confused smiley


Quote
Ohmarinus
After reading on, it seems that this is the kit I need:
[jtechphotonics.com]

I have gotten a bit of extra money from second-hand things I've sold this month and can afford to buy this laser. It will be $384.49 including tax. So I would have to calculate how much extra tax I would have to pay, it probably will be another 100$ for the Netherlands... Hmm, maybe I have to find another product... I realize this is getting very expensive.

It will cost me €409 euros, this is $500 USD. Hehe, okay, nevermind, I will forget about this.

Can I directly run this laser through my Ramps 1.4 or do I need to buy additional parts? I've seen Cozmicray's lasercutter and he seems to use the 1.7W version, so I would assume that I can use this 2.8W laser with the same setup as Cozmicray.

The 1.7W version will cost me 306 euros, or 375 dollars.
Re: Information needed before buying what I need
December 23, 2014 04:07AM
Quote
cozmicray
??? Where can you buy a CO2 laser rig (with optics, mirrors) for $335???

confused smiley
My remark was for the $500 that Ohmarinus estimated. A random example of CO2 close to that price: [www.ebay.com]
Of course, you can probably find it cheaper on taobao or if you dig further.


http://www.i3d.ro
Re: Information needed before buying what I need
December 23, 2014 06:02AM
Haha yes I mean that I want to use Ramps 1.4 to control the stepper motors, and to turn on the laser. Of course the driver that comes with the laser kit will power the laser. I only want to know if and how Ramps is able to configure the power output to the laser as sometimes you don't want to run it at full power. For example when the material is thick, you will make multiple passes over the material. I have the idea cuts come out nicer when you do two passes with 3/4th of the power than cut through in one go at 'full' power. It looks as if the material gets hotter when you do full power cuts and it looks more scorched somehow.

Maybe I should stick to the reseller I've found in the UK. They can offer me the same parts for around half of what it would cost to import it from the US. I could also try and finding an equivalent kit in Germany, as it has a well-developed industrial market. Only problem is that I don't speak German natively, aber ich bin Holländisch, und es ist möglich fur mich um ein bitchen Deutsch zu lehsen. Not sure if that was correct, but 'spoken' German isn't too hard to understand for me, the words we use are related to each other most of the time so you can make up for the words you don't understand, however, when it comes to e-shopping... hehe, well, let's just say that terms used in e-shopping don't sound anything like the Dutch words.

Time goes on, I'll check again if I can find any other sellers for 445nm lasers. In the Netherlands it's near impossible. Haven't found a single shop yet. All they sell is 445nm party disco lasers winking smiley


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 23, 2014 06:13AM
... be carfull with the 2.5Amps! - my 3.5W-diodes are rated to 2.3 Amps and give close slightly more then 4Watts when powered with 2.5Amps and gets hot after some ten seconds.

For varying powers I'm setting my diodes to the max. wished power (mostly 1.5 to 2Watts) and then adjust the power by pulse-lengths.

My 'lowest' power is done with 1 Microsecond pulses and speeds up to 80mm/s, the max. cutting power (for 4mm plywood) is done with 400µs pulses and speeds of 5 to 10mm/s ... and then in several passes.

Sometimes I have to reduce the power to prevent the fumes start to burn and so dirtying/carbonizing the surface ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 23, 2014 04:18PM
So how does one adjust laser power?
My driver has only adjustment for over current?
No adjustment to adjust current output to diode.

I suppose PWM the trigger port?
How does one know if trigger port can accept PWM
and what pulse with limitations?

confused smiley
VDX
Re: Information needed before buying what I need
December 23, 2014 05:19PM
... my drivers are all constant current drivers.

The first types were based on LM317/LM338 with 'fixed' resistors for the desired current/power or in parallel configuration with more of the LM chips and jumpers or switches to 'add' the current of the single LM's from the smallest value (300mA with the 445nm-diodes or 500mA with the 975nm IR-diodes) to an averaged amount of up to 25Amps for the stronger IR-types.

The newer types were OP-controlled, so I have a trim-pot for adjusting the current.

With changing the pulsing length I can 'average' the effective power for engraving with some Milliwatts to max CW-power for cutting ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 23, 2014 05:29PM
OKay, I've been looking at alternatives.

The first one was this OSRAM PLTB450B
[www.ebay.nl]

Found this datasheet:
[www.prophotonix.com]

Seems to have quite wide temperature tolerances too.

Found this one on a German site, VDX, do you know if this is a good kit? (2W)
[www.insaneware.de]

This one looks good too but I'd rather have more power like the one from the German site:
[www.ebay.nl]


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 23, 2014 05:41PM
... this 1.5W/1.6W-diodes are older types, then used in the DLP-beamers, so pretty cheap.

The 2W-module with driver looks common enough so could be worth the price.

My own 2W-modules are in a similar price range ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 23, 2014 07:28PM
Quote
VDX
... this 1.5W/1.6W-diodes are older types, then used in the DLP-beamers, so pretty cheap.

The 2W-module with driver looks common enough so could be worth the price.

My own 2W-modules are in a similar price range ...

Alright, so the one from the German site might be what I need.

"Analog modulation means that which a voltage between 0 - 5V moves, the laser diode
between 0 - 100% can adjust their performance.
If, therefore, for example, 2.5V applies it to the modulation input, the laser diode running at 50% of their capacity.
This driver is a "MASS BASED DRIVER", which means the laser diode is Regulated by the mass.
Especially Red laser diodes or lasers which her ground terminal on the housing "MUST" Isolated mounted
be. "

Since it's analog, I guess I can use Ramps to send out a signal to power the laser diode in percentages, is this correct? Or will the Ramps output not be stable enough and fluctuate? Can I even use an analog driver?

And another question, they talk about MASS BASED DRIVER, what does this mean?

Quote

Laser diode

9mm TO5
Wavelength: 450nm ~ (Blue)
Power: max. ~ 3000mW (CW)
Recommended Max Stom: 2000mA
Threshold current: 200mA ~
Life: ~ 20,000 hours (at 480mA)

Max power 3W looks good. I imagine that's why they advertise it as a 2W diode. I will probably run the diode at max 80% power anyway. 20.000 hours of use sounds good. I can imagine this being 10.000 hours when it's run at 80% or 1.6W

The only thing I don't understand still is what I have to do to actually have Ramps give the signal to the laser driver to tell at what modulation and power it should run. Oh, and I should get good glasses, the ones on the German site are a whopping 60 euros. I imagine them being available for a lower price. Do the glasses have to be specifically made for 445nm or, can I use 'general' protection glasses for laser?

Edited 1 time(s). Last edit at 12/23/2014 07:34PM by Ohmarinus.


http://www.marinusdebeer.nl/
Re: Information needed before buying what I need
December 24, 2014 04:01AM
Probably mass as in ground (GND).


http://www.i3d.ro
Re: Information needed before buying what I need
December 25, 2014 02:49PM
Thanks, I feel like such a noob..


http://www.marinusdebeer.nl/
Re: Information needed before buying what I need
December 25, 2014 03:06PM
Think I'm just going to buy from the German site. The only thing I need now are good safety glasses.

These seem good:
[thelittlebox.co]

Edited 1 time(s). Last edit at 12/25/2014 03:18PM by Ohmarinus.


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 25, 2014 05:56PM
... look at the
Quote

Life: ~ 20,000 hours (at 480mA)

This means, ye more current/heat, the shorter the life-time expectations, starting with 0.5A ...

And you'll need glasses specified for 445nm!


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 25, 2014 06:23PM
Quote
VDX
... look at the
Quote

Life: ~ 20,000 hours (at 480mA)

This means, ye more current/heat, the shorter the life-time expectations, starting with 0.5A ...

And you'll need glasses specified for 445nm!

Yeah, the last one I linked have this specification:
Protection again Blue / Purple (190-450nm), Red (635-660nm) and IR (>1064nm-2000nm).


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 25, 2014 07:23PM
... have you more data for them? - looks, as if that's not meant for full protection, but only for 'adjusting' the laser beams.

"Full protection" glasses are less transparent (mostly orange when against 445nm) and more expensive than "adjusting" glasses ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Information needed before buying what I need
December 26, 2014 07:14AM
Quote
VDX
... have you more data for them? - looks, as if that's not meant for full protection, but only for 'adjusting' the laser beams.

"Full protection" glasses are less transparent (mostly orange when against 445nm) and more expensive than "adjusting" glasses ...

I have emailed them for specific explanation on what the glasses do.

Would you know where I can order glasses? I have seen then cheaper than 60 euros, I think 60 euros is a bit of a rip off but the shop where I have found them cheaper was sold out.

Edited 1 time(s). Last edit at 12/26/2014 07:14AM by Ohmarinus.


http://www.marinusdebeer.nl/
VDX
Re: Information needed before buying what I need
December 26, 2014 01:29PM
... 'full protection' glasses are more around 150 to 300 Euros - look here for full protection glasses:
[www.laser2000.de]

... and 'only' adjusting glasses:
[www.laser2000.de]

This 60€-types have reduced capabilities - comparable to the adjusting glasses, but should work for this low-power diodes good enough ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
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