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!

A Major Award, and bracelet production notes

I won! I entered my bracelets in the Full Spectrum Laser monthly free laser tube contest for June and I won... so I get a free laser tube. You can see the entire entry with photos of my setup and notes on production on flickr or click any of the thumbs below. This is awesome, because my tube is losing power. I have to cut about 10-20% slower and at 10-20% higher power to get through 1/8" 3 ply than I did when the tube was fresh. Not so good since I'm in production for Craft Lake City which starts on August 9th. Yikes. I hope I get the tube soon but I'm scared to switch out a working one for an unknown. We'll see.

I've only got about 21 bracelets about a third of the way through production, and I hope to at least double that by the fair. I need more time in my life for this. Ugh. I have lots of earrings and jewelry stands to cut too. I also need to get a website and business cards done. Yay for crunch time.

Aluminatus is here

Aluminatus Package

It's here. Hopefully I'll have time this week to play with it and get it assembled... but not looking likely! I need some tinkering off time. Just to note, There was one ripped open bag of hardware, but all parts were still inside. The aluminum dogbone holes are definitely not centered, not sure if this matters yet. And the Magma hotend has a loose unseated pin and an almost unsheathed resistor (?). Some of the printed parts are pretty shoddy... there's boogers on the extruder head in a number of the holes. Haven't unpackaged it other than that. Updates soon.

Aluminatus Update

My Aluminatus 3D printer isn't here yet. First delivery date was Feb. 20th... that didn't happen. I've been avidly following the threads on the Trinity Labs Google Group. Lets just say I'm not chomping at the bit to get it here given all the issues the first batch of users are having. The first 50 were very much beta kits and it's been interesting to watch them figure out the bugs. Poorly printed bed holders and other parts, Extruders wired to move backwards, EMI problems from the steppers tripping end stops, damaged kapton heaters, blown MOSFETs, misaligned frames and Y-stages, poorly placed cooling fans, missing parts... etc. The last promised delivery date was the first week of April... so we'll see how that goes. TL has been assuring that all the bugs will be worked out for the next batch and that the retail price will now be much higher than we paid. No worries as I'm having too much fun with the laser cutter and barely have time to do that so the 3D printer might have a backseat for a while as the learning curve there will be WAY steeper.

Masking update

I've been doing a bunch of cutting on the 1/8" birch from WoodCraft for a design I'm perfecting, and after trying the plastic masking film someone recommended, I decided that paper film would be better. Well lo and behold a friend just happened to have two large 12" rolls of paper transfer tape for transferring sticky-back nylon laying around his shop that I happened across. It's labeled Masking Angel Tape. It's the same cream color as standard masking tape and has a medium tack I'd guess. I tried it out today and while it masked the char well, it also left behind a nasty residue from the burnt glue at the edges which doesn't come off easily. So... strike two. Plain old blue painters tape has been working the best by a long shot, so I picked up a 3-inch roll and will be using that from now on. Stick with what works. I've seen on some 3D printer groups (they use it to print on) that they bulk order it in larger rolls ... 6 inches or more... so that might be the way to go for larger cuts in the future.

I've updated the materials database with the above mentioned birch... and have some 1/8" bamboo ply on the way from Inventables.com. Not cheap at $8.56 per square foot plus shipping, but I used the $20 gift card that came with the laser to buy it, so we'll see if it's worth the money. It can be had for cheaper in much larger sheets.

Hansolo - Multiple pass etching

My friend Hannah drew this a few days back and I asked if I could have a photo of it to play with on the laser. She sent the first image. I figured I could have some fun with depth on the engraving, so I brought it into Photoshop, and did some manipulating and painted in some grayscale corresponding to the depth of engraving I wanted. I then brought that jpg into RetinaEngrave and setup 5 passes in the 3D Engrave tab by changing the thresholds to match that of the gray of the layer I wanted, set a different power and speed for each frame, and printed away. It took about 40 minutes to do the 5 passes on the 3" x 4.14" piece... though I realized some ways to optimize this when I run it again. The thresholds in RetinaEngrave aren't very precise so it ended up having a lot of stray pixels on each frame, causing it to do tons of unnecessary passes. Next time I'll just do the separations in photoshop and do each frame in the Engrave tab. Mental note to also expand the borders of each of the layers a bit so that there is overlap because the two deeper layers left ridges as they didn't go to the edge by a pixel or so. Regardless, pretty happy with how it came out. It needs a bit of sanding cleanup as I didn't mask it so the high points got slightly charred, but I'm excited to do more of this stuff... lots of ideas. 

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Software Side Note

I love the manual entry controls for Relative Location and the ability to quickly design vectors in RetinaEngrave itself. This allowed me to quickly cut the border and then cut the frame with precision as I'd forgotten to add vectors for it in Photoshop. Once the laser is homed, as long as your piece isn't moved on the bed, you can do all kinds of relative work from the starting position. Very nice. Overall... the software is growing on me. It's leaps better than I was expecting for sure.

Flexible Wood and clasps

Based on a number of designs on Thingiverse (here's one, another, and another) using the flexible hinge cut, I decided to make some bracelets. It appears this hinging design was created by Snij Lab in the Netherlands. Pretty ingenious and I can't wait to try some other patterns when I get a second. So I opened up illustrator and went at it. The design is nice and modular and easy to scale. Using 1/8" MDF board I cut at Power 82 Speed 30 masked with blue painters tape and the first bracelet came out perfectly. I wet it lightly and clamped it with some binder clips overnight while it dried and it now stays in form pretty well. I need to get some thinner more stretchy shock cord so it will slide on easily. I'll experiment with finishes and other woods very soon. Also need to try out some angled patterns for the cuts.

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Sweet! It works. I was curious if I could come up with a more interesting clasping mechanism... so I thought I'd try and use rastering to cut half way through the wood and make a locking join. I ran a bunch of tests on the edge of the wood to see what powers would cut half way through. I settled on Power 80 Speed 20 with two passes in Raster mode. I rastered one side, then cut it, then flipped it over and rastered the other side using the sheet it was cut from as a jig which worked perfectly. I'll need to tune the tolerances as I had to do some exacto knife clean up, but it appears to work pretty well. The small pieces on the outside are too fragile as I'd expected, so I'll have to redesign it a bit. Not sure if this is viable for many uses but I'll play with it more on an actual bracelet and see.

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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.

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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.

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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.

Masking no go

I tried the masking film I ordered from SignWarehouse on the 1/4" Birch Plywood and it mostly doesn't work. It's not tacky enough and as it melts it peels back away from the cut so the board still gets charred. It works where it sticks it just doesn't stick around the entire edge. Bummer... that was a waste of cash. Will have to find something else. [UPDATE] After a quick search on SawMillCreek forums I realized ordering plastic film as a mask was one of the least brilliant purchases I've made in a while. Don't know why I didn't think about it... I saw someone else recommend it on Thingiverse and just blindly ordered. Turns out plastic melts! Shocker. I've tried masking with blue painters tape before and it worked great. So now I need to source some PAPER transfer tape... or just buy a bunch of 3" blue painters tape. Hmm.

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?