Posts tagged #materials

Materials update etc...

Just a quicky update. I just added a couple of things to the Materials Database... which is still behind.  I replaced my tube 9/21/13, quite a while ago, and have been going full on since. Wow I haven't updated in a long time eh?! The tube upgrade went smooth, just followed the directions from FSL and it worked great first try. So good to have full power again. I've been researching a bit on getting a higher wattage tube from another supplier but haven't committed to anything yet. I'm going to upgrade once this tube starts to die. I participated in Craft Lake City last year and sold a bit over $1000 in jewelry and learned a lot... like that I never want to do craft fairs for a full time job, though I think I could do so and be successful at it. It's very stressful and the hours are super long. Having to shill your product all day and repeat yourself over and over just isn't my cup of tea. So as soon as the show was over I go my website rolling, SKIVVIES.COM. The name is a long story and probably not the best choice for a laser cut jewelry store, but I've had it for years and it was my nickname and screen name for so long that I couldn't think of anything else. So far business goes up and down with how much I'm willing to advertise. I know if I put more effort into it I'd do much better.

I've made a few new objects which hopefully I'll get around to updating soon. I'll do my best to update more often!

Posted on January 13, 2014 and filed under Laser.

Birch Plywood Testing and 3D Engraving

Quickly, here's some results from 1/4" x 2 ft. x 4 ft. Birch Project Panel Plywood that I picked up at Home Depot. It's got Birch veneer with "whitewood" core, which you can see in the first photo. Second photo is of the cut and raster tests. After that I ran a quick 3D Raster Engrave test. For cutting with 1 pass, it looks like Power 50 Speed 14 or so works well. Rasters are also nice.

RetinaEngrave 3D Raster Engraving

FSL's software is very good overall, but the newer 3D Raster Engrave function still feels like a bit of a hack. Instead of varying the laser power for each pixel, it has to do multiple passes at a single power. I'm not sure if other lasers have the aforementioned capability to engrave with one pass or if they all work this way. That said, it works pretty well.

You have to Print a grayscale image to RetinaEngrave, then click the 3D Raster tab or select if from the Tabs menu if it's not visible. Then you set the Raster Power and Speed settings and the number of "frames" you want (every frame is one pass of the raster engrave), then click "Auto Generate Frames." You can also create each frame manually if desired. After creating the frames you can go back in and edit their power, speed, and threshold individually. Creating frames basically slices the grayscale image and generates a Z-depth layer for each value of gray. The more frames you create, the greater your Z-depth resolution and the more passes the laser will take. So based on the original grayscale image, in final output to the cut material, a white pixel will get no engraving, a 50% gray pixel will get engraved to half of full depth, and a black pixel will get engraved at full depth. What that depth is depends on your power and speed settings, and how many frames/passes you do. Once you have the frames generated, each frame is a black and white representation of a Z-depth layer. So with every pass, black pixels will fire the laser and will get cut another layer deeper, white will not. Hope that makes sense. It's much clearer when looking at the software.

The first try was the large box in the upper left of the "TEST" Image above. It was 2.5" and was set at 500x500dpi with 10 passes. After the second pass I got impatient and realized I could test an image a quarter that size at half the resolution, and that I needed more power. Rastering takes forever! At that size and resolution, it's doing 1250 passes on the Y axis per layer/frame. So I went back to photoshop and quartered the size, reimported and upped the power to 40 per layer and the resolution to 250x250dpi. I kept it at 10 frames. That resulted in what you see below. Not bad, and I can imagine more frames would come out even nicer. I didn't record the time it took but it wasn't fast to say the least.

Pretty cool feature and I have some interesting ideas of what to do with it when time allows. It's going to take some experimentation.

Posted on March 21, 2013 and filed under Laser.

Dangerous Materials

Last post I mentioned I cut some ABS sheeting for a friend's project. As Angie Brennan pointed out to me on Saw Mill Creek's forums, this probably isn't the most healthy idea in the world. According to the ATX Hacker Space website, which has a very nice chart of what you should and shouldn't cut on their laser, the ABS "Emits cyanide gas and tends to melt." While I disagree that it doesn't cut well, at least in thin sheet form, it's probably best to heed the warning about cyanide gas. My laser is well ventilated and the negative pressure setup should send all bad stuff outside... I have no way of measuring or knowing so I'll be limiting this stuff in a big way. After a long search on Google my conclusion is this:

Pretty much everything you can cut with a laser will emit something that is NOT good for you to breath. Paper, plastic, acrylic... all of it. So ventilate well, even after the cut so any leaching from hot plastic is minimized, wash your hands, and limit cutting plastics as much as you can.

This is probably a good place to link to the Make page about determining unknown plastics. Better to find out what you are cutting than to breath chlorine or cyanide eh?

Posted on March 20, 2013 and filed under Laser.

Materials Testing

I've probably put about an hour of laser time on my tube by now, Here's the first few things I've been cutting and some stuff I've learned.

RetinaEngrave and Illustrator

I use Illustrator for a lot of the graphic design I do so naturally, I'm using it with the Full Spectrum Laser. Their print driver makes this VERY easy. Just hit print and off it goes to RetinaEngrave (which has to be open in the background and already connected to the laser). Here's a few things I've learned the hard way:

  1. Make sure you are in RGB mode in File -> Document Color Mode. The couple of times I had the file in CMYK, weird stuff happened. Notably, on one cut it did two passes on each vector line though it was only set to one, another time only some of the lines showed. 
  2. Use a line stroke of .25 or less. I found that anything over .25 would cause RetinaEngrave to double up the line in order to make the vector wider than the laser cut. I've been using .1 lately and it works great.
  3. Make sure Media Size is set to "FSL Hobby Series Gen5 20x12" in the Print Dialog box. When ready to print, make sure this is selected in the print dialog box or the print area might get cropped.
  4. Make sure artwork is within artboard boundary. In "Document Setup" make sure to make your artboard bigger than your artwork.
  5. It's important that line segments are joined or RetinaEngrave will treat each segment as a line and instead of following a path, will jump from line to line. For example, if a square is just 4 line segments, it may do the verticals first then the horizontals instead of just tracing the shape of a square if the vectors were all joined. We ran into this issue importing from CAD to Illustrator with a DXF file. The file was a large array of 6mm squares, initially importing them into RE took forever until I realized it was importing thousands of vector lines instead of hundreds of squares.

I'll update if I find anything else but overall I've been happy with Illustrator and RetinaEngrave. The scales translate and the cuts are true to size.


The test pattern that is included in the software is pretty handy, though I really wish I could specify the number of grid steps it does instead of the hard wired 7x10. It basically cuts a grid of squares starting at low power low speed in the upper left and ends with high power high speed in the bottom right as you see in the image to the right. This is great for working out the optimal speeds and powers for a given material. I'll probably end up making my own version of this since the software only allows you to change the upper and lower limits of the range for both speed and power but not the number of steps. I.E. you can tell it to test from 0-50% power and from 20-80% speed, but no matter what it will do 7 steps between those speed values and 10 between the power values. There is also a focus ramp test which I have yet to use but should soon.



After the first cuts on cardboard I grabbed some cheapo 1/4" 5-ply plywood from Home Depot I had laying around in the garage and had a go at it. It took at least 2 passes to cut through it and going really slow at full power. The charring around the cuts is really bad to the point of it being charcoal. I think this wood would etch really nice but for cutting, not so good.

So I ran to Home Depot and got a few sheets of 1/8 in. x 2 ft. x 4 ft. MDF Cut To Size Panel for about $4 each. I also got a panel of 1/4 in. x 2 ft. x 4 ft. Birch Project Panel Plywood (which I have yet to test). I cut the panels up into 4 20" x 12" pieces which left me with a couple 12" x 8" pieces per sheet. It cuts very nicely and I settled on a Speed setting of 30 and Power of 80 to get a nice cut. The char on the cut is nice but it does leave a pretty bad smoke stain on the top surface ... which is probably more glue gunk than smoke. I purchased some film (06.50 inch x 100 yds R-Tape Clear Choice AT-60) from today to see if I cover the pieces with that before cutting will prevent the smoke char on the top surface. The smell is pretty strong and it sticks with the wood for days if not forever. It also rasters pretty well as you can see in the lower left of the image to below.


It's pretty impressive how detailed and thin you can make the cuts and the piece is still pretty solid. Those "drips" are insanely tiny.

So after that I decided to try a long Raster Then Vector style cut and I came across these Palago game tiles on Thingiverse which looked like a great test, not to mention the kind of game I love to play. I redid the file in Illustrator CS6 (which you can download here). I cut at Power 85 Speed 30 and rastered at Power 70 Speed 100. Sweet. 


I've also cut sticky back ripstop nylon at Power 10 Speed 100 and it cut the nylon but didn't go all the way through the paper backing so it was perfect for peeling. No photo ATM. Next was skateboard grip tape... Jessup to be exact. I cut on the paper backing side and Power 60+ Speed 100 seemed to work well. I tried to cut from the front and just cut the front grip and not through the paper backing but no such luck. Regardless it comes out well and is easy to peel afterwards. Going to do some custom grip for my brother's skate shop FIDNA at some point soon. Results below: 


Lastly, today I cut some 1/32" or .9mm thick ABS plastic sheeting. It's textured on one side and shiny on the other and cuts well at about Power 100 Speed 80-90 from either the textured or shiny side. Though it does warp if you do a lot of very close cuts quickly as you can see in the test grid. We cut out a matrix of squares to fit around RGB LED strip lights that my buddy is using to make a large timer for his DLG comps... more explanation and photos once it's done since that probably makes no sense to anyone.



The only real problems I've run into with RetinaEngrave have been with the software hanging on launch, and it's usually just because I've pressed a button before the software was fully loaded. I've now learned to wait until it's connected to the laser, and the spinning wheel at the bottom left of the window is spinning. If it's stopped and I press a jog button, the software tends to hang.

Another bug is that every once and a while a jog button will "stick" and the head will run to the end of the axis. I've had this happen numerous times where I'll click quickly on a jog button to move the head and the head will just keep going until I click the button again or until it hits a stop. Still haven't quite sorted that out yet.

I've also just today had an issue where cuts along the X axis weren't as deep as those along Y which I haven't sorted... but I think is due to the guide wheel tension. I have to do a cleaning and alignment soon and will check this issue out then.

And lastly, the 1/4" ID hose on the air assist pump blew off today mid cut and scared the shit out of me because I had no idea where the loud buzz was suddenly coming from. Which reminds me... I need to find a quieter air assist. The one from FSL is crazy loud and by far the loudest component of the system. I can't cut at night in the house with it or my 2 year old would not be happy.

Posted on March 17, 2013 and filed under Laser.