Laser engraving plastic

[Pilgrim22]

I have to make about 20 labels like this. All are different size and shape upto around 50mm x 50mm. I can cut the final shape on a guillotine and belt sander but the engraving is a problem.

I have a cheap generic 3018 rotary engraver but its really hit and miss trying to get the depth of cut right. I thought about a laser engraver but im not sure if it would work well or just burn through or melt the plastic.

Does anyone have any experience of using a laser to make labels like this?

 

[Agroshield]

I think that sort of dual-layer two-colour plastic meant for mechanical engraving has a trade name that is used as a generic description (like Hoover is used for vacuum cleaners).

Search around a bit for laser engraving <whatever that trade name is>. That might give you a flavour of how possible it might be.

You can certainly buy something that is in principle similar, gives the same finished effect and is specifically designed for laser engraving:

Laser engraving plastic sheets | Trotec Laser

Laser engravers and cutters for advertising signs, directional signs, data plates, name tags and more. Get more information now!

www.troteclaser.com

What I do not know is if the mechanical engraving stuff and the laser engraving stuff would be compatible or interchangeable.

 

[clift_d]

The multi layer plastic material is called Traffolyte - you can buy sheets of it online if you've got your own machine to do the engraving, including material intended for laser engraving, but it might just be simpler to go to someone that can cut your labels from a digital file.

 

[Dr.Al]

I've used a Trotec laser cutter to do this sort of thing and it worked very well. Unfortunately I don't have access to it any more (it wasn't my laser cutter). It produced a very clean result. I think the Trotec lasers are rather expensive, but for a shallow cut like this I would imagine that cheaper laser cutters would work okay. An example:

 

[JMS1972]

I had a quick look at the Traffolyte catalogue as I'm interested in the answer too!

The laserable material is three layers of acrylic which is fine for CO2 lasers.

The machine engraving stuff has Acrylic on the outsides and ABS in the middle I don't think you can laser ABS....

Well you can as long as you don't mind the Cyanide gas it emits

 

[Ali]

There are two types of multi-layer plastic, one is for laser engraving and the other is for rotary engraving. The rotary stuff doesn’t work well with lasers - the laser type (usually) has a painted surface whereas the rotary stuff has even thickness layers. If you are laser engraving a material with a dark top coat and light base layer you might find the dust stains it - no amount of cleaning will make this right, the best solution is to take two passes on the engraved fill area before cutting the profile shape. Trotec sell the materials.

 

[julianf]

I have to make about 20 labels like this. All are different size and shape upto around 50mm x 50mm. I can cut the final shape on a guillotine and belt sander but the engraving is a problem.

I have a cheap generic 3018 rotary engraver but its really hit and miss trying to get the depth of cut right. I thought about a laser engraver but im not sure if it would work well or just burn through or melt the plastic.

Does anyone have any experience of using a laser to make labels like this?


View attachment 462847

As others have said, you need a different material for lasers.


The reason you are finding the lettering hard to do is that your machine is not regulating depth according to the surface. It's effectively a mill rather than a dedicated engraver.


If you look at spindles by gravograph etc (ie dedicated engraving spindles) you will see that they are sprung loaded (or gravity on a ball slide) and sit on the work with a depth regulating nose cone, though which the v cutter passes.


For finer work the nose cone itself will be a ball and socket, so that, not only does it track depth, but the ball also rotates to average out any undulations in the surface. Obviously the spindle stays perpendicular (average) but the depth regulation is adjusted to the undulations.


If you only have 20 to do, why not get a block of something, level it to the machine itself (bed levelling program) and then adhere the job to your pre levelled block and run them all in one hit?

 

[Onoff]

I'd 3D print them.

 

[Pilgrim22]

The plan was to engrave them but i think my machine just isnt stable enough. I thought about one of the cheap lasers like this one...

https://www.amazon.co.uk/Engraver-Installation-Required-Operate-Engraving/dp/B083V2H1L7/ref=sr_1_6?crid=2IFCLFDZCYXBR&dib=eyJ2IjoiMSJ9.RoniU_d57vEPNaT6emUTiYD3CYxzdTn7x-TeNlalj_9pOEiY-Us_cG8kRHzpo4ZwC7d8JbaVnzwHh7dHB2NJBHginqu2MuJYN5rajWfVGEwG0er6MhlkSRrbNmY494tWkps4tp3c9T3kioJ1LW7hiLlKpOpA5fgSaI0Gc4h-ijXq7YVcEH3OsrcRHGN1ubiwY3VW1hPseMv6ZHvovtSdBMsutHXgP8_dOxUfoi0Dqr6gw7XngXDOiabcfM2hrafK0KW-sdxY8Bk0Vd9hz4LAP8d0GWefhi48lGtOgpLYKqI.dM0QxCD4BUedMTmH8uF3xD1m5GHk4gPFJE_lKTbvFAs&dib_tag=se&keywords=laser+engravers&qid=1724825682&sprefix=laser+engravers%2Caps%2C148&sr=8-6#customerReviews

But I wasnt sure it would do what I needed, I suppose I could order one try it and send it back if its no good.

I thought about buying a laser head and fitting it to my 3018 router but im not sure about the stability and stuff melting. I'm going to strip the routed down and see if I can make the whole thing more rigid and stable and then try again with the rotary spindle. I think I'll also try the bed leveling sensor and see if that helps.

Thank you for all the suggestions

 

[julianf]

If you get totally stuck, send a sheet of the material here (not individual parts, a sheet) and ill engrave them all.

Ill send you back the sheet with reference / alignment marks cut onto it, and you can route them out at your leisure.

I dont want to get into milling it, but running some text over it isnt too much bother.

edit : please do have a DIY go first though - i mean its not a job that im especially wanting to perform, but, if you cant do it yourself....

 

[Newlands]

I only ever use acrylic on my CO2 machine, as so many other sorts of plastic either give off nasties or just burn and melt. Diode lasers are pretty useless even for acrylic unless it’s very dark in colour. I think you’re right to have a go with the 3018 - I think there is loads of advice on the net for getting them working well.

 

[Agroshield]

...it's really hit and miss trying to get the depth of cut right

Could you describe this in more detail as we may be able to give some pointers that will assist. Are you pointing to a machine (overall) limitaton, machine inconsistency (lack of repeatability) or to practical difficulties you are having establishing the relationship between the top of the part and the end of the cutter?

As above, is your bed level? Have you tested it? Chuck up a cutter with the sharp end in the collet and jog down until you trap a fag paper between cutter end and bed. Move somewhere else and see if the same Z-height achieves the same degree of trappedness.

Clamp/stick/vacuum a small piece of material to the bed. Mill some grooves the full length of the material to make a grid. Measure the material thickness and the groove depth (or material remaining below the bottom of the groove) and see if every place you measure is the same.

If it is touching off on the top of the material you are struggling with, again the fag paper can help. You could also use a scrap of material and cut grooves of increasing depth until one is correct. Then note the Z-depth and transfer that to your G-code without changing the machine setup.

 

[Pilgrim22]

If you get totally stuck, send a sheet of the material here (not individual parts, a sheet) and ill engrave them all.

Ill send you back the sheet with reference / alignment marks cut onto it, and you can route them out at your leisure.

I dont want to get into milling it, but running some text over it isnt too much bother.

edit : please do have a DIY go first though - i mean its not a job that im especially wanting to perform, but, if you cant do it yourself....

I appreciate the offer mate. I'll see how I get on with rebuilding the machine and let you know how I get on.
Thank you anyway

 

[Pilgrim22]

Could you describe this in more detail as we may be able to give some pointers that will assist. Are you pointing to a machine (overall) limitaton, machine inconsistency (lack of repeatability) or to practical difficulties you are having establishing the relationship between the top of the part and the end of the cutter?

As above, is your bed level? Have you tested it? Chuck up a cutter with the sharp end in the collet and jog down until you trap a fag paper between cutter end and bed. Move somewhere else and see if the same Z-height achieves the same degree of trappedness.

Clamp/stick/vacuum a small piece of material to the bed. Mill some grooves the full length of the material to make a grid. Measure the material thickness and the groove depth (or material remaining below the bottom of the groove) and see if every place you measure is the same.

If it is touching off on the top of the material you are struggling with, again the fag paper can help. You could also use a scrap of material and cut grooves of increasing depth until one is correct. Then note the Z-depth and transfer that to your G-code without changing the machine setup.

I really need to start from scratch with the machine. Iveno bed leveling device, it's a cheap and nasty setup at the moment.
I'll keep you posted once it's sorted and I'm ready to try again.

Thanks for the advice

 

[Pilgrim22]

I only ever use acrylic on my CO2 machine, as so many other sorts of plastic either give off nasties or just burn and melt. Diode lasers are pretty useless even for acrylic unless it’s very dark in colour. I think you’re right to have a go with the 3018 - I think there is loads of advice on the net for getting them working well.

I may need to pick your brains about lasers in the near future.

 

[Newlands]

I may need to pick your brains about lasers in the near future.

not sure there’s a lot to pick to be honest! I built my own CO2 machine (following a YouTube series from a bloke in NZ), and last year I bought a small diode laser on a bit of a whim. I suppose I learnt a fair bit in the process, and there is loads of info available. One of the better resources is the Lightburn forum, and some of the posters there are real experts. Fibre lasers have got much cheaper in the last couple of years but I know nothing at all about them.
Things the CO2 do well - slate coasters, engraving wood of any thickness, cutting wood thinner than 10mm (ornamental stuff like table mats, eco-friendly hippy type earrings etc, and especially acrylic enclosures or switch panels.
The diode lasers are a bit more feeble - thinner wood stuff, black acrylic is ok but slower than the CO2, but if you’re doing something else while it’s running you can just let it get on in the background.
A CNC router is better if you’re cutting thicker wood, especially plywood or mdf.
Eg Xmas decorations done on the diode, an house-point token thingy engraving on the co2 for my daughters school, and some ply templates for a guitar my lad made, done on the CNC router.

 

[Pilgrim22]

Spent several hours trying to sort this poxy mill out but its a piece of ****e.

So I'm going to try to turn this pile of bits into a half decent router that I can also attach a laser to.

I'm thinking 700 x 700 x-y and a 250mm z axis. the idea was inspired by this video

I'll post my progress