MP3D converted to Laser Step by Step

I’m trying to convert my 3D printer to a laser cutter. I’m new to the 3D printer world and have been learning Fusion 360. My prints have been coming out well and now I would like to try cutting/etching.
For my prints I’m using Fusion 360 and Simplify3d.

I have purchased

LA03-7000 445nm 7000mW Blue Laser Module 7W Fixed Focus DC 12V TTL/PWM Modulation w/ Heat Sink DIY Laser Engraver Machine for EleksMaker

I have applied power and the laser will definitely cut through wood. I’ve also created a mounting plate that will replace the hot end of the 3d printer.

Now for my questions:
1: Which fan output of the Mini-Rambo board should I connect the PWM input of the Laser?
2: Using Fusion 360 as the starting software, what other software will I have to get and learn to get a file for input to Simplify3d?
3: Do I even need Simplify3d for cutting/etching?

In general, none of my cronies are into this area of fun and I need step by step instruction of how to get from an idea to a cut piece. BTW, I have a low rider that I will be finishing up when the weather gets warmer.

Thanks for any help!!

There isn’t a single way to drive the lasers. This one looks pretty versatile. How comfortable are you with changing the firmware on the mini rambo? I can think of two ways to drive it and the better way is to change you fan pin to one of the 5V PWM compatible pins and driving it with that. The other way is through the existing fan port, but since that is low side drive, and the PWM isn’t differential, you’ll probably need a pull up resistor and it will be inverted.

W.r.t. 2 and 3. I haven’t used simpify3D, but that is for extruding, lile other slicers, right? It won’t do CAM for laser work. You can use estlcam or imageToGcode (or is it image2gcode, I can never remember which one is better). There is also a jtech plugin for inkscape that supposedly works pretty well.

A few things to be aware of with fixed focal length lasers. They are usually very short distance length. About 10 to 20 mm. They are intended for etching metal so the distance doesn’t usually matter. that means they also can’t cut deep into wood because the cone shape of the beam would be blocked by the surface of the wood. Cutting deep into wood is best done with a longer focal length so the beam stays tight for a longer distance.

Also the short focal distance allows smoke to get to the laser lens. That can cause permanent damage to the lens.

Here is some good info on different lens types.

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Thanks for the information about the focal length and the smoke - I didn’t think about that. I plan to use the laser for cutting cardboard and wood up to 1/2 inch (mostly balsa). Like you said, this laser is good to 18 mm (about .70 inch). I hope to learn and then step up to a new longer focal length after the MPCNC is put together.

I’ll be adding a side draft fan - Thanks again!

I can change the firmware in the mini rambo, but I need to get all the parameters from the current software install. Any ideas or pointers to accomplish that? After I get the parameters out of the board, what’s the next step(s)?

You are correct, Simpify3D is a slicer. I’ll look into the suggestions that you have given for conversion to Gcode.

Thanks for your help!

M503 from the console will print a lot of information, including the eeprom settings, and (if it is recent enough) a version number from Ryan (like 412). That should be close to enough to rebuild it to the same state.

You can look at the marlin firmware page on the docs, but basically, you’ll download a preconfigured version from Ryan’s github, change just the laser pin, and flash it. Then check with M503 to see if there are any eeprom settings you’d like to change.

So you can change the fan pin in pins_minirambo.h to be the value of the min x endstop, then wire you 5V pwm to that pin, and you should be able to control the laser with fan commands, M106/M107.

When they say that the focal distance is 20mm, that’s the distance it will be in focus, not how deep it can cut. That’s the focal depth, the distance that the beam is in focus for.

Thank you Very much for the details. I’ll give this a try.

Ahh, now I get it. Thanks for the explanation and clarification.