Adding a Small Laser to the machine

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TReischl
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Adding a Small Laser to the machine

Post by TReischl »

So there I was, surfing around YouTube and sure enough, it has now cost me about $130. This is pretty funny. I spent most of my career in and around industrial laser cutters but I had no idea about small low power (compared to what I had been working with) diode lasers.

My plan is to do some engraving and marquetry, mostly marquetry. From what I can tell cutting veneer is going to be pretty slow with this power level, that is ok, I am in no hurry and I can always purchase a more powerful laser. BTW, none of this if for commercial sales. It is just something I have wanted to do and cutting veneer with a fret saw, or slicing just always seemed really tedious to me.

One of the challenges is that I will have to modify a post for Mach 3. No Z moves, but I need to turn the laser off at the end of each pass (the spindle commands will be used since they are wired in via a relay. And of course I will need to turn it on at the beginning of each cut. I currently use Gerry's most excellent Mach3 Screenset PP which produces:

N0 G00G20G17G90G40G49G80
N10 G91.1
N20 G94

N140 S12000 M3 (the M3 needs to be moved to a line after the G0 on the next line)
N170 G00 X-0.8796 Y1.0225 Z0.2000 (All the Z moves need to be removed)
N180 G1 X-0.8796 Y1.0225 Z-0.0400 F30.0 (This entire line could be removed)
N190 G1 X-3.6723 Y1.0225 Z-0.0400 F150.0
N200 G1 X-3.6723 Y3.3534 Z-0.0400
N210 G1 X-0.8796 Y3.3534 Z-0.0400
N220 G1 X-0.8796 Y1.0225 Z-0.0400

(An M5 needs to be added here to turn off the laser)

N230 G00 X-0.8796 Y1.0225 Z0.2000
N240 G00 X0.9675 Y-1.1545 Z0.2000

(An M3 needs to be added here to turn on the laser)

N250 G1 X0.9675 Y-1.1545 Z-0.0400 F30.0
N260 G1 X3.9361 Y-1.1545 Z-0.0400 F150.0
N270 G1 X3.9361 Y-3.8152 Z-0.0400
N280 G1 X0.9675 Y-3.8152 Z-0.0400
N290 G1 X0.9675 Y-1.1545 Z-0.0400

N300 G00 X0.9675 Y-1.1545 Z0.2000 (Entire line could be eliminated)
N310 G00 Z2.8000 (Entire line could be eliminated)
N320 M5
N330 M883
N340 M30

I am going to go read up on modifying the PP and see what I can come up with, but something tells me I am going to need some help before it is all over.

The laser will not be here for a few weeks. I am looking forward to any input on setting this up. Thanks!

Ted
"If you see a good fight, get in it." Dr. Vernon Johns

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TReischl
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Re: Adding a Small Laser to the machine

Post by TReischl »

Well!!!! This went way better than I expected. Maybe it is because I read the instructions FIRST for a change. Minor miracles will never cease.

I created a new post and it now outputs:

N1 M5
N2 G00G20G17G90G40G49G80
N3 G91.1
N4 G94
N5 F50.0

N7 G00 X-1.2732 Y3.0455
N8 M3
N9 G2 X-3.1115 Y1.2072 I-1.8383 J0.0000 F50.0
N10 G2 X-4.9498 Y3.0455 I0.0000 J1.8383
N11 G2 X-3.1115 Y4.8839 I1.8383 J0.0000
N12 G2 X-1.2732 Y3.0455 I0.0000 J-1.8383
N13 M5

N15 G00 X-0.7125 Y-1.0885
N16 M3
N17 G3 X1.3963 Y-3.1973 I2.1088 J0.0000 F100.0
N18 G3 X3.5052 Y-1.0885 I0.0000 J2.1088
N19 G3 X1.3963 Y1.0203 I-2.1088 J0.0000
N20 G3 X-0.7125 Y-1.0885 I0.0000 J-2.1088
N21 M5
N22 G00 X0.0000 Y0.0000
N23 M883
N24 M30
%

This is no great shakes because most of it consisted of removing things not required for a simple laser cutter. Anyone wondering what the M883 is for at the end: This is a macro call used by Gerry's Screenset 2010. I am not sure I need it so it may disappear too.

Edit: I have looked at the M883 macro. It sends the machine to a "park" position. I really like that, very handy.
"If you see a good fight, get in it." Dr. Vernon Johns

Timvmax
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Re: Adding a Small Laser to the machine

Post by Timvmax »

Looks like you've got that covered. What power is the laser you are getting?

RhoTu
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Re: Adding a Small Laser to the machine

Post by RhoTu »

Should be a fun project. I bought the Emblaser a couple of years ago through kickstarter and have used it for various projects. Their model 2 now has a Z height control so that you can vary the focal point and get deeper cuts. Just a thought, you may want to retain that feature in your PP.

HTH

RT

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TReischl
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Re: Adding a Small Laser to the machine

Post by TReischl »

The laser is 2500mw (2.5w). I am cheaping out on this one just to see what I can do and if it will be useful. It does not have TTL so no PWM. If it proves really useful for cutting veneer I will probably buy more power and features. But for right now I will control the power via feedrate. That should work.

I hear you about the Z. The reason it is gone right now is that it will make the initial testing and operation much easier. Not to mention I would have to figure out how to get the Z positioned and THEN turn on the laser. I run Screenset 2010 and one of the handy things is that it supports a touch off with a retract to an exact height that is configurable. Sooo, the plan is, once I figure out the optimum focal height, I will use that for the retract and presto! I will be able to engrave on different thicknesses without any fooling around. That is the plan anyway. . .
"If you see a good fight, get in it." Dr. Vernon Johns

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Re: Adding a Small Laser to the machine

Post by ger21 »

I spent a bit of time at the User Group meeting looking at the diode laser they had running. I'm not sure it's powerful enough to cut veneer without a lot of burning. I guess it depends on your expectations whether the results will be acceptable. I'm interested in your results.

I'd like to build a standalone machine for engraving using one of these diode laser. As soon as I finish the million other things I have on my plate.
Gerry - http://www.thecncwoodworker.com

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TReischl
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Re: Adding a Small Laser to the machine

Post by TReischl »

Hey Gerry,

I am not sure it is powerful enough to cut veneer either. It seems no one has posted on YouTube doing it. Lots of 3mm balsa, but no veneer. Balsa is a way different animal. The veneer I cut will be about .030 so I am thinking maybe. . .just maybe.

A long long time ago, in my other life several customers were using 1500w CO2 lasers to create artwork, they also had burning issues because they could not run the machine fast enough or lower the power to a reasonable level. The solution was honey comb with a decent suction underneath. Served two purposes, held the material down and it stopped the show surface burning issues.

I am ok if it only does engraving/marking. For the ridiculous low price what the heck!

Just finished up making a mounting clamp that fits around the router with a vertical plate to attach the laser module. I will be able to remove the laser easily and not mess up the router in the process. Once it comes in it should be ready to go in short order.
"If you see a good fight, get in it." Dr. Vernon Johns

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Re: Adding a Small Laser to the machine

Post by ohiococonut »

Sheesh!
Now you've got me thinking I need to add one of these instead of buy a standalone unit. Which in my case may not have a large enough area without spending a ton of money.
I have two thoughts, which gets me into trouble sometimes. First, set the optimum focal point and set my z clearance height as far as I can go to eliminate burning when it moves. I'll probably have to increase my z speed.
Second, add a relay to my controller to shut the laser off when it has to retract to safe height and back on when it reaches cutting height.
Maybe both, I dunno, my gears are starting to grind now. :shock:

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