Tips for Buying a Laser Cutter/engraver

Hello this is Geordie and I wrote the "10 Tips and Tricks for Laser Cutting and Engraving" instructable. For close to 2 years I ran the laser cutter/engraver at my local maker space, ADX Portland and I continue to use their laser to make my own artwork and designs.

One of the most common questions I've received since posting the "Tips and Tricks" instructable, is people asking me for advice on buying their own laser. So I've decided to write a quick instructable about that.

Disclaimer:
I’ve only ever used one machine and that is the Epilog Helix laser at ADX Portland. So that is the only machine I can talk about directly. So rather than reviewing specific companies and machines this article is going to be more about what to look for and think about when buying a laser.

Step 1: The First Issue Is Support.

There are a lot of cheap imports, mostly from China, on the market. But lasers are complicated machines and they do break and need to be repaired. Make sure the company you buy from is reliable and offers good support for you and their machine after you buy it.

Here are some questions to think about:

How hard or easy is it to get replacement parts?

Do they have tech support?

How easy is it to get a question answered?

Do they have a good website?

Are there tutorials on how to use and/or fix the machine?

Can it be upgraded?

Step 2: Choosing a Machine. Size and Power.

The two main issues I would focus on when it comes to picking a machine are the size of the bed and the power of the laser.

The machines bed size will determine how big a piece of material you can fit in the machine to cut or engrave. A bigger bed will allow you to cut or engrave larger pieces and even if your doing something small, like laser cut jewelry, a bigger bed will allow to cut out multiple pieces at once rather than one at a time. Also some machines have a fixed bed and some have a bed that can go up and down. A bed that goes up and down allows you to engrave different sized objects. The cutting depth doesn’t change but if you want to engrave a logo on a leather shoe rather than on a flat piece of leather, having a bed that you can lower to get the shoe in the machine is important.

The next issue is the power of the laser. The strength of the laser is measured in Watts. The more watts the more powerful the laser is. The laser, I used, started out with a 30 watt laser and was then upgraded to a 50 watt. The strength of the laser is most important for cutting. Remember the thickness of material that a laser can cut is determined by the focal point of the lens and not the power of the laser. So adding a more powerful laser won’t allow you to cut thicker material. But it will allow you to cut faster and more reliably. A weaker laser will mean having slow the laser down to be able to make good cut.

I would suggest getting the largest machine you can and starting with a weaker laser. A bigger bed will allow you to work on bigger designs or cut and engrave multiple pieces at once. You can upgrade the laser in it to a more powerful one later.

Hope this information helps out. If you can’t afford your own laser I would suggest looking for Maker space where you can use their laser or find a shop that will engrave and cut for you at a good price.

Geordie

Comments

[ChristinaM31]

Is there a laser cutting machine that can cut and engrave both leather and copper?

[trimbandit]

"Remember the thickness of material that a laser can cut is determined by the focal point of the lens and not the power of the laser. '

Can you explain this? My understanding is that for cutting thicker material, you want to use a focus lens with as longer focal length(and therefore a longer area that is in focus). Since the effective cutting power is reduced when going from a shorter focus lens to a longer focus lens, you would want more wattage to compensate. Correct me if I'm wrong,v I'm still figuring this stuff out

[geordie_h]

The laser cutters I've worked with, which are the hobby to basic business models, have a fixed focal length. You can't adjust the focus like you can on a telescope or microscope. Maybe there are more expensive/professional machines that can change the focus but I don't know about them.
As a result beyond a certain depth the laser loses focus and starts to spread out and weaken.
The 2 things you can adjust are usually power 0% to 100% and speed that the laser travels. By adjusting those you determine the cut. Your most powerful (for thick material) is a high power and slow speed so the laser stays on the material longer and the weakest (light engraving) is low power and high speed.

[trimbandit]

For all the cheap Chinese made lasers, you can swap the fixed lens, so I would be very surprised if you had a laser where you could not replace the lens. I mean you need to be able to swap it if it becomes damaged.
Basically with a shorter focus, you get finer focal point which is better for high resolution engraving. However, the "in focus" portion of the beam is very narrow. A longer focus lens will have a longer section of the beam that is in focus, which is better for cutting thicker material, however even at its tightest point, the "dot" will be considerable wider. Hence, this is not as good for engraving, but better for cutting, especially if you have a higher power tube (since the beam is not as tightly focussed).
Here are a few links with basic explanation:
http://www.engraversnetwork.com/files/Choosing-the-right-Laser-lens-tip-sheet.pdf
https://www.troteclaser.com/en-us/knowledge/tips-for-laser-users/selection-of-the-right-lens/
http://support.epiloglaser.com/article/8205/42831/focus-lens-101

[geordie_h]

I did not know that. Thanks for the info.

[MohamedAshraf89]

So, What is the specification that specify the material thickness / and material type also ?

[RubenV58]

Hi,
I am new to this field and I must admit it is very intresting. I am thinking of using an engraving machine with the purpose of cating the polimer coat on failibg flash memory cards, like SD cards, for later accessing thier data when the normal won't work.

Since I can't try and err, I have severeal questions.

1. As the many types of memory card types exist, in the market, the different polymer's chemical composition those may have.

Does this composition fact influences on how to calibrste the engrabing machine?

2. If each polimer has its own psrameters it needs, how woild I know the right calibration for just custing out the shield without affecting the metal surface where actually the data is stored?

3. I presume that finally, a polymers are just a group of materials at certain range of heat power. What is the minimal power in wats which such a laser machine should emmit for this kind of tasks?

Thank you for any help provided!

[Michael-Imagination-Technology]

Geordie,

Just curious, have your receive your Glowforge machine yet? If so how is it working?

[Mrbonesagain]

Geordie, thanks for the great information. I'm looking to purchase a small laser engraving machine to mark my product which is made of bone. I'm not sure where to start. The surface is small, about 1" wide and 7" long. I also work in wood. Is there a site that sells multiple machines that I could talk to to help me sort it out, thanks Steve Brown

[geordie_h]

I've only worked with an Epliog laser so I can't compare brands to well. I have a Glowforge on order but its been back ordered for a while.

The first bit of advice I have is make sure what ever you buy, make sure it has good support. You might get a Chinese knock off cheap but if it brakes do you really want to call China for tech support?

Make sure the bed will fit not only the side to side dimensions you need but also the depth. Some of the hobby level ones only work on thin flat material.

Best of luck.

[Mrbonesagain]

Geordie, Thanks, good advice. I've connected with a Makers space and will have access to their laser for now. Then maybe I can learn more to purchase , thanks again, Steve Brown

[JimH29]

Great advice, Geordie. The same for your Tips and Tricks article. I'm just starting to consider using laser etching on wood, and not quite grasping the line width capabilities of laser etching. I will be mainly doing vectorized portraits, and up to now I've been routing them with a trim router loaded with a 12 degree carving bit. I need to know if a laser engraves various widths (according to the vector you're copying) by making more passes until it fills out a wider area in some parts of the image. For example, for the carved image I'm including, would the wider lines ( like the throat and mouth area) be done, or just a thin line for each part ( like the whiskers)? The image is about 6 inches high, and 4 inches wide. Thanks for your help.

[MarcH88]

Hi JimH29,

Generally speaking a CO2 laser works in two modes:

1.Vector

2. Raster

. . . . . or a combination of both.

Vector mode is usually used for cutting and raster mode is used for engraving. Vector mode can also be used for engraving fine lines by using lower power. With an engraving/routing system the cutting tool needs to follow a path and this path is generated as vector lines. With this method, an area which has an outline that then needs to be 'filled' has to have additional lines inbetween the outlines set with an appropriate offset that is equal to or less than the cutter width to ensure full removal of the material you are engraving.

With a laser system such as the Epilog Helix used by Geordie_h, any line within the artwork set to 'hairline width' or <0.005" will be treated by the laser as a vector line and will work in 'cut' mode. Line widths above this will then be treated as raster mode which can be set to different dpi settings.

With your vector portraits, I assume that you are creating the artwork in Adobe Illustrator or something similar using the 'pen tool' to generate vector shapes that when the points are closed, create 'filled shapes'. When that image is 'printed' to the laser, unless it is told otherwise, the resulting output will be a 'rasterised' image.

The image below is a vectorised graphic - it is the same image but the one on the left will be 'rastered' by the laser whereas the one on the right will be 'cut'. I hope this helps.

[JimH29]

Wow! Thanks for this thorough and detailed explanation (you told me what I wanted to hear)! And thanks for the example photo. I forgot to mention in my question that I will be engraving in soft wood, like cedar, pine, and fir. The deepest I would need to go would be 3/32", 1/8" max. What wattage module could I use for that depth? Again, thanks a million for your help. Jim

[MarcH88]

Hi Jim,

I can only comment on my experience with an Epilog laser, but even the entry level 30 Watt system is capable of cutting through 6mm woods in a single pass using 100% power and 20% speed. Cutting through 3mm woods would be around 60% power and 70% speed. The Epilog website is very informative and you can download the user manuals. Take a look at the entry level Zing manual:

https://www.epiloglaser.com/assets/downloads/manua...

Page 147 & 148 show suggested material settings for common materials and there are some great tips on how to get the best engraving results. If you want a professional machine it is worth paying the extra for an Epilog system - It's made in the USA and have metal 'waveguide' tubes with ceramic components manufactured by Epilog themselves (standard 2 year tube warranty with typical lifespans of 3 - 5 years). The desktop machines are all air-cooled requiring no water chiller.

I hope this helps.

Marc

[JimH29]

Yes, it does. You've been a great help to me, Marc. I'll start looking now. Thanks.

[geordie_h]

Good advice.

Thanks

[geordie_h]

The important thing to realize about most lasers is they can't vary the thickness of the beam. You can fill in areas but this is done in the engraving settings. Basically the laser goes back and forth over an area, moving down the width of the beam until it has covered the whole area. Vector art work is great for this. Any area with a fill will be engraved and any line that is thicker than the cutting line will also be engraved.
Engraving does take longer than cutting so if your paying based on time it is more expensive. But I would stress worth the money. The look is great.

[JimH29]

Thanks,
Geordie. That's what I wasn't quite getting. So I'll be able to do what
I'm planning. I don't know if you saw the example I was showing in the
instructable comments. It's a portrait I router carved, and am wondering
what wattage laser module or tube I can use for only doing that. It
will be in soft wood, and only about 3/32" to 1/8". Thanks a lot for
your help. Jim

[geordie_h]

Another thing to know about lasers and engraving is that they are designed to burn the wood not remove it like a router. The engraving is deeper than the surface but you really can't control the depth.

Most lasers are in the 30 to 50 watt range. The higher wattage will burn things faster.

Before you buy a laser you might want to rent time on one or have someone run some samples for you so you can see what a laser will do.

Have fun.