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ArcticMyst Security by Avery

Adding etching laser to MY CNC - help

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Newbie who has spent the last few hours trying to come up to speed and searching everywhere to see what's involved in adding a laser to my existing CNC. My CNC is a large commercial style. I'd like to be able to add etched details in my wood creations and sign the back of my signs and plaques with my business name and logo. CUrrently I do this with a branding iron - not the best solution.:banghead:

I've been building and repurposing things for years. What I was surprised was that I have been unable to find any simple add-on retrofit. :thinking: To me this means there is some issue I don't know. Since my CNC is well made I can hold a level (focus) laser no problem down to .001 inch. I can control the X and Y speeds and program the designs. I have no problem building a mouint on the carriage and I also have 220v single phase power. What I would like to be able to do with the machine is to:

1. burn or etch into wood or wood products.
2. Cut thin parts < 4mm to allow for fine inlays
So what type of laser could I mount on my cnc and do the job faster than a turtle but I don't need to go as fast as a rabbit.:yh:

A couple of problems:
Shielding the laser when it's on and operating.
removal of smoke and cleaning the air while it is operating.

:bowdown:So I know this group will get me headed in the right direction or shut me down.

Jim
A retired engineer trying to hack my through retirement one cool project at a time. ;)
 
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Hey,

Welcome to LPF!

I think a 30W 1064nm laser would get you exactly where you need to be :beer:
 
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And where would I begin my search to acquire such a laser? Remember I know very little or from the POV of most eveybody here nothing?
 
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I would look up "Epilog" lasers I think they are called. They have 30W IR lasers that will cut almost anything.
 
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I know about epilog and $7000 unit, I'm looking to add it to my existing CNC machine.
 
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MagnaMagicBtu thanks for the idea. I think I have a ways to go before I start this project. Too many questions I need to answer before I blind myself or burn down the shop.
 
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Hey mate, welcome to LPF.

For wood engraving only, you will not need anything over 10W. Have a look through ebay, you should be able to find a 10W C-mount 808nm infrared diode for ~$200. You will also need a c-mount laser host (again consult ebay) to put the diode into.

The only other thing you will need is a driver for the diode, but since you are going to be driving it from a CNC control board I would suggest building your own. Other members can advise you to the exact schematics, but it would be pretty easy to make. Some large caps for filtering and some mosfets I assume.

BUT for cutting, you have no choice but to grab a 40W CO2 tube. They are just great bang for buck. But mounting it to a CNC router will be quite difficult, as they are long glass tubes requiring water cooling and high voltage supply. You can opt to use an RF excited CO2 laser which is more compact, air cooled and requires low voltage to run. How ever you will still have an issue with mounting and they are a little pricey.

-Adrian
 
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>bobhaha wrote--- BUT for cutting, you have no choice but to grab a 40W CO2 tube. They are just great bang for buck. But mounting it to a CNC router will be quite difficult, as they are long glass tubes requiring water cooling and high voltage supply. You can opt to use an RF excited CO2 laser which is more compact, air cooled and requires low voltage to run. How ever you will still have an issue with mounting and they are a little pricey.

-Adrian
__________________<



Adrian,
What I was hoping to budget was in the under $1500 range for power supply and Laser and some technical help to synchronize turning on and off the laser when cutting. My y movement is 18"" and my x movement 60" and i have a 5 " z movement which I was planning on adjusting to focus the laser.

So I still have a long ways to go to see if this is possible under my conditions.

Jim
 
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Hey mate,

Sounds like a decently sized machine. What I have seen others do is connect the lasers enable pin to the Z axis DIR pin on the CNC board. If yours works the same as most do, your CNC board should latch the DIR pin HIGH or LOW (meaning 5V or 0V TTL logic) which would work well in this application. All you would have to do is script your logo to be only 1 step high (I think its called a plunge cut of 1 step depth) so that when your machine moves one step down it'll turn the laser on and when it moves up it will turn it off. Obviously when you are cutting with the router you will have the laser power supply off and when you run the laser you will have the router off.

For a budget, that is a decent range to work with. A second hand RF CO2 laser is ~$1000. I personally own the same model laser as this ebay listing:

Synrad J48 S2 J48S2 75W Watt Laser Used Sold "AS IS" | eBay

You can see my thread about it here:
http://laserpointerforums.com/f43/probably-most-expensive-laser-forum-85841.html#post1244226

Just note that the laser in the ebay listing is a 25W laser, not its advertised 75W. It will be capable to cut for 4mm wood but probably nothing thicker than that with out multiple passes.

But there will STILL be an issue with mounting it. You can mount it to the back of your gantry and then have 2 mirrors pointing the beam to the cutting head which would be mounted next to the router head. But these systems are very dust sensitive and need an air assist pump and air lines to the lens. If you had a way of protecting the lens, mirrors and laser output lens while the router was being used, then this would make the project viable.

Personally I would go with the C-Mount solution, only because it is so compact and parts are cheap if you ever need them replaced. I personally have never used a 10W C-Mount diode, so I'm not sure how well it will focus to a dot. They have multiple emitting dyes which are usually in a square shape which is inherently difficult to focus to a round point. But of course the downside of this system is, it can not cut 4mm _anything_

-Adrian
 
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Thanks for all the info. You really gave me some things to think about. Regardign your comments, ideally I like to come up with some way to remove the laser and only put on when I wanted to use it.

I really need to see someones home built so I cna get a better idea how these things are built.
 
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Yeah, cutting is definite CO2 laser territory. But for burning/etching, you don't even need a watt. Some
of us (myself included) have done wood burning with a diode out of a DVD burner drive. It just takes
longer. The more powerful diode lasers require correcting optics which will also add cost. You will get
faster travel rates, though, so it might be worth it.

Also, using the Z axis for laser control obviously isn't going to work on your setup since your machine
already has a Z axis. Any unused axis will work, though. You may need to upgrade your controller if it
doesn't have one.

This can be either removable or use a CO2 laser, but not both. The reason is because CO2 lasers are
bulky, sensitive to vibration, and so have to be mounted in a fixed position. The beam is then reflected
into the work with mirrors. Removing any piece will throw the whole thing out of alignment. Vibration is
also not particularly good for DPSS. Fiber coupled will probably be too expensive. That prettymuch
throws out anything except direct diode lasers. So you're not going to be cutting anything with a
removable setup.
 
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Yeah, cutting is definite CO2 laser territory. But for burning/etching, you don't even need a watt. Some
of us (myself included) have done wood burning with a diode out of a DVD burner drive. It just takes
longer. The more powerful diode lasers require correcting optics which will also add cost. You will get
faster travel rates, though, so it might be worth it....

Lighting Stalker -:bowdown::thanks: You really cleared up an issue. Since I can do CNC for cutting, cutting with the laser was a really nice to have but you explained the dilemma of doing that so now I'm backed to something I can remove or cover really well to just etch or inscribe. I'm comfortable on the software side to get the laser to write where I want and manually focusing to the correct Z level would not be that difficult.

:thinking: Here is my theory on using the diode path. If I can somehow attach the laser to my router be it permanent or removable, I could zero the laser just Like I zero my router, Then once it is focused the software would treat as though I was just cutting on the surface an I could Z UP which would take the Diode out of focus move to a new location and Z down back to the focused position to continue burning. I have repeatability to .001 on my machine.


The whole goal in my woodworking is to add another element to my carvings. Carving and laser etching on the same piece could look amazing and unique.:cool:

Summarize: Can I go with a focused laser that would do a pretty good job of burning wood faster than a snail.

Can I get a thin line with a diode and some sort of optics, I'd like to get a really thin line when I burn which probably require some sort of optics to focus the laser so I get a precise and more intense burn?



I have scrapped laptops that have old cd and dvd burners. Can I use the LED laser from one those and get acceptable burn penetration in wood at a reasonable feed rate? :confused: It might be the perfect first step. I'm a experimenter but that doesn't mean I'm a expert at anything. :shhh: Where do I begin learning about the LED laser?

If I mount to the router then I will have the laser underneath a dust shield so that I will have shield from the laser. Will that be enough of a shield?

Are Diode laser still dangerous if the laser is mounted down so that it can't be looked at directly? I know about reflection so even if I reflect I will be under the dust(smoke ) shield. Is wearing safety goggles enough?

I believe getting an LED laser is the right way to go because I can get a system running easier and I'll learn a lot along the way.

I've moved a mile in the last few days with everyones input thanks:gj:
Still have to keep moving and learning but simplifying the first laser is the right way to go.
 
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Summarize: Can I go with a focused laser that would do a pretty good job of burning wood faster than a snail.

Yes, but with higher powered diodes you need one that has a FAC (fast axis collimator)
"lens" to focus to a point (actually a tiny square).

Can I get a thin line with a diode and some sort of optics, I'd like to get a really thin line when I burn which probably require some sort of optics to focus the laser so I get a precise and more intense burn?

I'm not sure why you would want a line, but that can be done by just focusing the output of
a bare diode (no FAC). I've never seen an AR coated line lens, though they probably do
exist. That would give a very wide line which will probably not burn very well. It might be
something to experiment with though if you can find an AR coated line lens and are up for
it.

I have scrapped laptops that have old cd and dvd burners. Can I use the LED laser from one those and get acceptable burn penetration in wood at a reasonable feed rate? :confused: It might be the perfect first step. I'm a experimenter but that doesn't mean I'm a expert at anything. :shhh: Where do I begin learning about the LED laser?

Now don't confuse an LED with a laser diode. They are very different devices. We are
talking about laser diodes here, not LEDs. That said, I don't believe those diodes will get
you the feed rates you're looking for. Yes they will burn, but it will take time. You want a
diode in the 3+ watt range with a FAC.

Since you're new to all this, it would be a very good idea to read through the stickies
posted in the General section. There are some special tools you will need for working with
laser diodes. If you hang out around here long enough, you will learn everything you need
to know.

If I mount to the router then I will have the laser underneath a dust shield so that I will have shield from the laser. Will that be enough of a shield?

Yes as long as there is no way to see the dot on the piece of wood (or where the dot would
be in the case of an infrared laser (actually there is a dot, but you cannot see it)).

Are Diode laser still dangerous if the laser is mounted down so that it can't be looked at directly?

Yes. High powered diode lasers are still very dangerous any time you can directly see the
place where the burning is taking place.

I know about reflection so even if I reflect I will be under the dust(smoke ) shield. Is wearing safety goggles enough?

They have to be special laser safety goggles which are rated for the wavelength and optical
power of your laser. Like I said above, if the place where the wood is actually being burned
is not visible under any circumstances, then you do not need any protection. It's a good
idea to get some though because you will be doing testing without the shield attached.

Special optical windows are also available that block the wavelength of your laser, but still
allow you to view the burning process. You may still need welding goggles though
because the light given off by hot glowing objects in the laser's path can be very intense. It
doesn't pose the same eye damage hazard as the actual laser light, however.

 
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Yes, but with higher powered diodes you need one that has a FAC (fast axis collimator)
"lens" to focus to a point (actually a tiny square.) "I'm not sure why you would want a line?
I am BAD :whistle: I was wondering how dense (small) a dot (square) I can focus so I can engrave thin lines on the wood. e.g. .50mm (.0025 inch) width line?


Now don't confuse an LED with a laser diode. They are very different devices. We are talking about laser diodes here, not LEDs.
:oops:Sloppy me I know the diff between LED and Laser diode.


So I'm off to reading more in the sticky area.

Lightning Stalker:yh:
If you can push me to some specifics topics to read that would be great. I definite am now focused at the high powered Laser Diode. I am confident I can get the mechanics to work just need to get some equipment that will work and begin building something.

:anyone: Does anyone have a recommended source for a high wattage Laser diode, associated power supply (although I do have some older Power supply bricks that are pretty high wattages) and have enough background to drop the voltage while still having the wattage available.



:drool: I think I am ready to order some gear and start working out the issues. I'm a hands-on kind of experimenter/hacker. If I can get started I will pioneer my way to a destination. I just don't want to end up with arrows in my back :yabbem:

Here's a picture of the CNC machine I am trying to add the Laser Diode to.
8619-cnc-machine-i-want-add-laser-diode-burn-inscriptions-business-logo-my-work.jpg

It does not have the dust shield/collector on in this picture So you can see the spindle position. (It's a water cooled 2 HP spindle)
 
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