[eli]

Hi. Thanks in advance for any help you can give. We just bought a desktop laser engraver for our pen turning business. It's a 40W Co2, run by MoshiDraw. We've got it hooked up and running and I've somewhat successfully engraved a few wooden pen cases. I say somewhat because the text isn't as crisp as I would like, the carving is very shallow and I can't figure out how to carve deeper without burning. I tried engraving a pen last night (moderately hardwood) and it was terrible. It barely etched the surface, but was very dark and blotty. If I turn the power (is that the ammeter?) back too far, it just sort of mars the surface a bit, if I turn it up much it carves more deeply, like I want it to, but also burns quite a bit, and the characters become oversized. We have been getting the pens and cases engraved professionally, and they are nicely carved with the text, with very little, if any, darkness from burning.
So I'm wondering - how do I get crisp, clean lines with text and engrave about 1mm deep without getting the burning?
Sorry if I've used the wrong terms for anything...completely uninitiated here.

[Litografa]

First of all - better provide more information about laser - manufacturer, model, type of tube, software and etc. In this case answer will be faster and may be can help you.
In your case picture of possible problem will be helpful as CRISP/NOT CRISP is different for different peoples

[eli]

Thanks for the response...I was hoping it was just something general and simple that I was totally missing...Okay, here's some more info.
I'm not sure of the manufacturer...it's a Chinese import into Canada and they've slapped their own company name on it. All Image Printing, model AIP-E40W. I don't know what type of tube, other than 40W. Software is MoshiDraw. I've been varying the carving speed, the partition and the power to get these results.
Here's a pic with crisp text, done by a professional engraver, no idea what machine they used.

Next I tried engraving the same text on a case and it's either too dark and "burnt", as seen here...

Or if I go light enough that it's not "burnt" looking, then it has barely etched the surface, as seen here...

Another example of professionally done, and how I want mine to look...

And then here's what I get on the same pen...

Even worse...


So, to sum up--I want that crisp, carved, not "burnt" looking text. I either get very burnt, or light, but not etched deeply into the surface text. TIA for any help.

[mcphill]

Have you tried multiple lower power passes? You don't need to cut the entire depth in one pass.

[MacGyver]

Multiple passes are going to help, but ideally you would be using air assist to keep flaming down. Also consider masking your wood with some painter's tape (or again, ideally with sign transfer tape) to cut down on cleanup from smoke damage.

[tootalew]

the tape will also allow you to paint the engraved text, as the pen barrel is already masked.

[LaserImage]

It looks to me like it's out of focus and/or you have dirty mirrors or lens. Check all of your mirrors and lens to make sure they are clean and then very carefully set your focus then try again.

[eli]

Okay, I've cleaned the mirrors and checked focus. I tried engraving another pen, using painter's tape. That didn't make any difference in regards to burning too deep, or barely marking the surface. I tried multiple passes with the power meter turned right down and it still wanted to burn deeply in certain spots (the same certain spots each pass) and barely mark the surface in others. In fact the tape had big holes in some spots and had barely discoloured in other spots, so the depth of the carving is very inconsistent. That led me to wonder if it was the curve of the pen throwing things off. I engraved a line of text on a case and it looks quite good. Using the EXACT same settings I tried engraving on a pen and ended up with a mess. It carved deeply in some spots and not in others. It can't be that the type of wood I'm engraving on (Purpleheart) doesn't engrave well, because we've had it professionally engraved many times before, in fact, on the same pen I'm practising on. I've also been practising on a Black Walnut pen and getting the same miserable results, if not worse. The last pen in the pictures I posted earlier is Movingi, which isn't a terribly hard wood, and the cases are maple, just FYI. Thanks so much for helping, everyone.

[MacGyver]

Ouch! Purpleheart? It's one of the more difficult woods to carve, so yes, it can be the wood. It's a heavy resin wood, so it's difficult to engrave without setting on fire (this is where air assist comes in). Walnut will give you a very dark engraving with heavy charring. The maple should engrave well, but the contrast won't be very high.

The tape I mentioned has practically zero effect on depth. Read my post again on what I suggested it for.

Also, have you aligned your beam? The optics could be perfectly clean but an undentered beam or out of alignment motion system will lead to uneven engraving/vectoring.

My best advice? Don't assume anything. Just because it was done well by someone else don't assume that means it's easy to accomplish the same thing. I bet good money the person who was doing the engraving for you had a more complete system than what you're working with right now (such as having air assist).

[zax15uk]

Eli, have you tried adjusting the DPI/LPI settings?

I have found some woods work great if you use a higher power and faster speed, with a lower DPI. In contrast others require less power and multiple passes at high DPI.

As others have suggested, air assist may help with reducing the charring.

Zax.

[Litografa]

Please output same file on another material - better on Alumamark. See result - if result is the same - image not sharp, different colors of engraved area - my opinion will be tube.
How long do you use this tube? It was installed in laser from factory? Is everything ok with cooling?

If engraving on Alumamark will be OK - choose another wood/pen