My little brother is a dual-service veteran and has a birthday coming up in a few days. Only the best for him, I’ve spared no expense on his birthday card… 
[attachment file=105575]
[attachment file=105576]
[attachment file=105574]
– David
Very cool! All I ever get on my birthdays from my brothers are bad dad jokes. So who does your brother root for during Army/Navy games?
I hope you get to send your brother many more cards.
Thanks.
Actually, I can’t remember ever getting him a birthday card. Just trying to get back at him, I guess… and this one is special. He’s actually been printing birthday cards for me for years. I’m such a slob…
He’s not a football fan so no heartburn there…
I hope I do, too.
– David
It’s funny, but the painting might have worked better than an actual photograph. I love the meeting of CNC and art like that. The fact that the computer can create something exactly from the mind is amazing, and poetic.
Then add the layers of abstraction thinking about someone imagining that scene from memory, and recreating it with their arm. Then scanning it in and you being able to find it on the Internet somewhere and recognizing what it represents to you. Then recreating it again, in a new medium, using a mechanical arm. The machine’s arm being it’s own work of art, combining thousands of clever solutions from complete strangers by an enthusiast for pure entertainment.
It’s really magic. Epic magic.
Startling discoveries… and pleasant to boot!
I went to my stash of hobby plywood and found some 1/8" (3.18mm) stuff from Revell… it actually measures 3.34 mm or so right now. I engraved the BD card with the exact settings (2/3 power, 20mm/s feed, 0.2mm resolution) for the cereal box cardboard (is this really what they call “chipboard”?) and got pretty mediocre results. But it’s starting to push 100 degrees outside now and I really didn’t want to go out and cut and sand the card outline. So, I started playing with my air-assist setup again to see what it would take to cut the 3.3mm ply with the laser…
I’ve started using a modified version of Danowar’s Air-assist shroud and nozzle recently (documented a few posts back) and saw/felt little difference between the MIN and MAX settings on air-flow actually coming out the stock nozzle. But I had seen a much stronger, higher-pressure, air-flow when I choked it down with one of those flexible Loc-Line coolant/air hoses and smaller nozzle. So I got into Onshape and whipped up a little extender nozzle that fits onto the end of Danowar’s stock nozzle. The OzarkTrail air-pump is actually for inflating air-mattresses and other inflatables… and is spec’d to actually pressurize them to a few psi. Sure enough, the nozzle extender concentrated the flow of air around the laser beam significantly and I was actually able to cut 3.3 mm plywood in only 2 passes at full-power and 100 mm/s feed rate with my little 2.5 watt laser!
The nozzle extender…
[attachment file=“nozzle_extender-2.png”]
[attachment file=“nozzle_extender.png”]
“Installed” on the stock nozzle…
[attachment file=105694]
[attachment file=105695]
[attachment file=105696]
Silly me! I was going to make 3 passes for the outline – just to make sure I got a complete cut – and then accidentally bumped the gantry and it skipped a step or two on the last pass. Since this is just a practice piece now, I picked the piece up on completion of the last pass and, to my surprise, the card all but fell out on its own. Two passes had been enough to completely cut through the plywood!
More later. I’m stoked!
– David
