Laser Etching on a 3D surface

Post Reply
SteveT
Posts: 8
Joined: Sat Jun 25, 2022 5:22 pm
Model of CNC Machine: Onefinity X-35 Woodworker
Location: USA

Laser Etching on a 3D surface

Post by SteveT »

I want to laser etch a hiking route onto a 3D terrain map - see the picture below, where I sketched on what the hiking route might look like.
Typically when I make a terrain map, the cut depth is around 40mm (1.57"). So the laser etching would need to go from 0 (Top of hill) down to -40mm depth.
I'll probably need to get a laser lens with at least 50mm(2") focal length
Does the laser module allow z-axis control so that when I'm etching the hiking route, the laser stays in focus over the whole height of the etching.?
Has anyone done anything like this ?

Thanks
Steve
Attachments
IMG_6512.jpeg

User avatar
Adrian
Vectric Archimage
Posts: 14544
Joined: Thu Nov 23, 2006 2:19 pm
Model of CNC Machine: ShopBot PRS Alpha 96x48
Location: Surrey, UK

Re: Laser Etching on a 3D surface

Post by Adrian »

Provided you have a 3D model that you can load into Aspire/VCarve then you can use the Project onto 3D model option in the toolpath to get the laser to follow the contours.

User avatar
scottp55
Vectric Wizard
Posts: 4713
Joined: Thu May 09, 2013 11:30 am
Model of CNC Machine: ShopbotDesktop 5.5"Z/spindle/VCP11.5
Location: Kennebunkport, Maine, US

Re: Laser Etching on a 3D surface

Post by scottp55 »

AT on Katahdin ??
I've learned my lesson well. You can't please everyone,so you have to please yourself
R.N.

martindg
Vectric Craftsman
Posts: 107
Joined: Thu Nov 28, 2019 6:12 am
Model of CNC Machine: Onefinity X-50 Woodworker
Location: Fresno, CA

Re: Laser Etching on a 3D surface

Post by martindg »

I've done this quite a bit. Obviously you would need to first project the laser cut toolpath onto the 3D model. Incorporating Z movements into your laser toolpath is a matter of modifying a post processor in order to include Z movements. I actually have two laser post processors that I routinely use - one that incorporates Z movements for use with 3D models and one in which I edited out all references to Z movements for flat etching projects.
46748F1C-21C9-49A1-B935-9E262AAFEA9C_1_201_a.jpeg

SteveT
Posts: 8
Joined: Sat Jun 25, 2022 5:22 pm
Model of CNC Machine: Onefinity X-35 Woodworker
Location: USA

Re: Laser Etching on a 3D surface

Post by SteveT »

scottp55 wrote:
Sun Feb 05, 2023 4:36 pm
AT on Katahdin ??
Well spotted, this is Katahdin. End of the AT. A friend of mine did this a while ago, another is doing it this year, so I thought it'd make a great gift.
martindg wrote:
Sun Feb 05, 2023 4:52 pm
I've done this quite a bit. Obviously you would need to first project the laser cut toolpath onto the 3D model. Incorporating Z movements into your laser toolpath is a matter of modifying a post processor in order to include Z movements. I actually have two laser post processors that I routinely use - one that incorporates Z movements for use with 3D models and one in which I edited out all references to Z movements for flat etching projects.
46748F1C-21C9-49A1-B935-9E262AAFEA9C_1_201_a.jpeg
Martindg - Your image is exactly what I'm trying to do, your Yosemite looks brilliant. What Laser are you using? and did you need to have a different focal length lens to allow for the z axis movement so the laser doesn't crash into the 3D terrain anywhere?

Many thanks for the help on this. I didn't want to spend on a laser unless I knew I had a path to do what I want.

Steve

martindg
Vectric Craftsman
Posts: 107
Joined: Thu Nov 28, 2019 6:12 am
Model of CNC Machine: Onefinity X-50 Woodworker
Location: Fresno, CA

Re: Laser Etching on a 3D surface

Post by martindg »

I decided on the JTech 7w laser as it has a focusable lens. The 14 ad 24 watt models while providing more power involve multiple diodes so do not include a focusable lens. I spent quite a bit of time talking this through with Jay from JTech at the Vectric UGM and determined that the 7 watt was the correct model for doing these 3D etchings. I use a 40mm focal length with the standard lens which provides a nice tight spot and allows for enough unimpeded movement to the depth that I am etching.If you have questions contact Jay at JTech; he's a great guy and will talk you through their models and which will work best for you.

As for the post processor modifications, I think you're using a Shapeoko which I believe is a GRBL based machine so the modifications are pretty straightforward. I'd be happy to share my post-p modifications if that would help.

Doug

SteveT
Posts: 8
Joined: Sat Jun 25, 2022 5:22 pm
Model of CNC Machine: Onefinity X-35 Woodworker
Location: USA

Re: Laser Etching on a 3D surface

Post by SteveT »

martindg wrote:
Sun Feb 05, 2023 6:04 pm
I decided on the JTech 7w laser as it has a focusable lens. The 14 ad 24 watt models while providing more power involve multiple diodes so do not include a focusable lens. I spent quite a bit of time talking this through with Jay from JTech at the Vectric UGM and determined that the 7 watt was the correct model for doing these 3D etchings. I use a 40mm focal length with the standard lens which provides a nice tight spot and allows for enough unimpeded movement to the depth that I am etching.If you have questions contact Jay at JTech; he's a great guy and will talk you through their models and which will work best for you.

As for the post processor modifications, I think you're using a Shapeoko which I believe is a GRBL based machine so the modifications are pretty straightforward. I'd be happy to share my post-p modifications if that would help.

Doug
Thanks Doug, great advice and help. The 7W saves a little money too. I'm on a Onefinity X35 now. I'll update my profile.
Once Ive got the laser I might reach out for some help.

martindg
Vectric Craftsman
Posts: 107
Joined: Thu Nov 28, 2019 6:12 am
Model of CNC Machine: Onefinity X-50 Woodworker
Location: Fresno, CA

Re: Laser Etching on a 3D surface

Post by martindg »

I also have a Onefinity but I use the OpenBuilds BlackBox as my controller. If you're using the BuildBiotics controller then the post-processor modifications will be a bit different than what I use but shouldn't be hard to set up. Let me know when you're ready and I'll be happy to help.

pviljoen
Vectric Apprentice
Posts: 53
Joined: Mon Jul 19, 2021 9:14 pm
Model of CNC Machine: AvidCNC

Re: Laser Etching on a 3D surface

Post by pviljoen »

I am trying to do the same. My problem how to move the laser so that the matches up with xy point zero for the spindle.

Please could you help me with my questions?
1. If you set your xy point zero with the touch plate, how do yo get the laser to start from the same point. NOTE: laser is mounted to the right and behind spindle.
2. Did you wright a macro (g-code) to move the laser head or are you using the xydatum + offset in the Material setup screen.
3. I presume that an offset can be both positive and negative.

kaetamer
Posts: 35
Joined: Mon May 12, 2014 3:10 pm
Model of CNC Machine: CNCRP Pro 4824

Re: Laser Etching on a 3D surface

Post by kaetamer »

May I ask for a clarification? Adrian’s option of using “Project onto 3d Model” seems to utilize a 2d object (line with X,Y values) onto a 3d model, whereas martindg’s approach sounds like he is utilizing a 3d object (line with X,Y,Z values) and a modified pp (a ‘normal’ laser pp which incorporates Z movement) - will either produce the same accuracy of line placement on the model? Thanks.

grantw
Vectric Apprentice
Posts: 92
Joined: Thu Jun 29, 2023 11:53 am
Model of CNC Machine: Sienci Long Mill

Re: Laser Etching on a 3D surface

Post by grantw »

pviljoen wrote:
Fri Aug 25, 2023 9:29 am
I am trying to do the same. My problem how to move the laser so that the matches up with xy point zero for the spindle.

Please could you help me with my questions?
1. If you set your xy point zero with the touch plate, how do yo get the laser to start from the same point. NOTE: laser is mounted to the right and behind spindle.
2. Did you wright a macro (g-code) to move the laser head or are you using the xydatum + offset in the Material setup screen.
3. I presume that an offset can be both positive and negative.
I believe that we are taking this somewhat off topic, so my apologies to the OP.

My laser head is also mounted onto the router mount of my CNC router. In my case, it is in front, but the issue is the same. I did write a macro to move the laser point to the same XY0 position as the router started from. Yes, it can be both positive and negative. In fact, I have two macros. One for projects where I run the router tool path(s) first and one for projects where I run the laser tool path(s) first. I am using the Jtech post processor.
To create the macros, I put a v-bit in the router, set XY0, and made a very small dimple on the spoil board. I turned on the laser and jogged until the laser spot was precisely in the centre of the dimple. Using the XY coordinates at that spot, I created the macros to jog that amount. Quite simple, really.
Grant Wilkinson
Ottawa ON

wb9tpg
Vectric Wizard
Posts: 456
Joined: Tue Sep 04, 2018 2:49 pm
Model of CNC Machine: Shapeoko 3 XL

Re: Laser Etching on a 3D surface

Post by wb9tpg »

pviljoen wrote:
Fri Aug 25, 2023 9:29 am

2. Did you wright a macro (g-code) to move the laser head or are you using the xydatum + offset in the Material setup screen.
I use a post processor I modified that sets the offsets using Gcode automatically. It also sets the CNC in Laser Mode.

So I just select that Gcode and run it.

I do find Z movement of 3D work useless. The laser sits only 1/8" above the work surface and it's a large head so there is no way lowering it use useful to me at all. I just use a set Z and rely on the focal length of the laser to do the job
Gary Mitchell
Kentucky, USA

Post Reply