Darkly Labs Community

Some questions about the air assist and distance sensor on the Emblaser 2 and Core

So I’m working on adding an automatic third axis to my Emblaser 1 and am having a bit of trouble narrowing down the best sensor to use, so I figured I would ask you guys since you’ve already worked it out. What type of sensor are you using? Sparkfun part # SEN-14722 looks like a decent option, but isn’t nearly as accurate as I’d like. A capacitive sensor might work since the engraver has a metal base plate, but I think that would prevent me from using it with any metallic stock material. I’m planning on using an Arduino to take the inputs from the distance sensor and then control a stepper motor to move the laser up and down to compensate for changing material thickness.

 

I’d also like to add an air assist module to my engraver, is there a way to integrate the distance sensor into the nozzle shroud? Is there any active control over the air assist? As in does it turn on/off when needed or does it just output the entire time a cutting job is active? I have a 1/5 HP airbrush compressor sitting right next to my Emblaser as is, would that be powerful enough to use as an Air Assist pump? 

Bump.

Hi Blake,

We do not use a sensor for height detection in any of our machines. There are too many limitations to the types of materials with sensors.

If you has the $$ you could consider an optical approach, but I believe this would involve a lot of development.

The air-assist accessory for the Emblaser2 and Emblaser Core do work through the nozzle already. They are also controlled by the firmware to turn on/off as needed. This is set in LightBurn.

Your compressor requirement depends on the size of the aperture the air will exit from. Our compressor is small, so it doesn’t take a lot of power to get decent air-assist results.

Domenic, 

 

Wait, so if you guys don’t have height detection then how are you accomplishing the engraving of curved objects that you advertise? How is the Z axis controlled?

Is there a pin on the Emblaser 1 board that I could use to control the air assist? I know that I can’t power the compressor off the board, I mean just the logic of turning it on/off. 

The nozzle I currently have on order for testing has a 4mm nozzle. How much PSI would I have to push through that to achieve similar results to the Emblaser 2? 

The Emblaser2 optics has a wide depth-of-field with its focus (+/-3mm). This is enough to engrave onto moderate curvatures like a pen, etc.

The E1 board does not have any triggerable pins like that. You would need to engage it separately.

Start around 8-10 psi and check your results.

Any way to get that with the E1? Different lens perhaps? Does the depth of field being ±3mm does that mean you have about 6mm of vertical engravable space? 

Would just letting the air run for the entire time be a problem? 

That’s it? Wow, my compressor can push out 50 PSI and potentially more, that’s just the most I’ve ever used with it. Seems like it’s a perfect option. I’ve got some components on the way (nozzle, tubing, fittings, etc.) and am working on some 3D printable parts so once I have it assembled I’ll post a thread in the E1 section. My last question is the distance you use to focus the laser is also the distance used to engrave right? I assume so but wanted to make sure before I go designing my new nozzle and it’s mount. 

The E2 uses a completely custom lens system which is what gives those results. I do not know of any suitable lens that fits the E1 diode module to achieve that result.

Leaving the air-assist on shouldn’t be a problem apart from noise and extra electricity use.

Yes, the focus distance is technically the distance from the material that gives the sharpest laser spot. This will give you the sharpest engraving detail.

If you wanted to ‘smooth out’ the detail, it’s not uncommon to un-focus the laser (or not set it to the exact focus height). We sometimes use this to speed up large engravings that do not rely on very fine detail.