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sexta-feira, 2 de janeiro de 2015


Sometimes things simply fail.
Some of them, they simply get old and die.
Other, die because of terrible design mistakes.
Last Wednesday, a coworker stood up and walked away from his workplace.
After a while, we heard a loud bang and some colleagues started complaining of power loss.
A small power adapter had burned and short circuited with a loud bang!
And here it is...

Looking at it, I wonder how it didn't had any worse damage or even a fire!!
The two input cables were simply gone with their remains wandering inside the plastic case.

domingo, 9 de novembro de 2014

It's blowin' in the wind...

I've been eying vacuum forming for a long time.
It's a quite interesting technique although it only suits some particular projects.
I'd love to use it for some cases (raspberry Pi perhaps) and other ideas but...
I've tried with some pet bottles and that plastic, simply shrinks.
Saw someone who used PEHD (the same from plastic bags) and it also shrinks.
I've found PP drinking cups but, no luck at all, as you can see:
Perhaps it is the hot air gun, perhaps it's temperature, but for now, it's just another failure and I have no clue!!

segunda-feira, 3 de novembro de 2014

Taking a plunge on a drop of UV gel!!

I've been imagining a long time ago how to create small 3D pieces without a 3D printer.
I had an somehow ingenious and low tech idea: how about manually impress UV resin with a UV led and a stencil?!
Well, it would require at least some automation in the z-axis but, I'd deal with it later...
So, I set to find some cheap UV resin in small quantities with no luck.
I could find it on eBay but not for cheap and it would also take at least 5 weeks to arrive.
Than, it just occurred me to use UV Nail Art Gel, and yesterday, finally found it in a local store, although not cheap at all! About 7€ for 8ml... But heck, I do need it!!
I rushed home to test my ideas... I'd use the included brush to deposit a small 3mm diameter drop on a reused plastic cover and set an UV led above it.
I'd check from time to time on it to guarantee its hardening but... although it was solid it felt like... rubber!!!
After some 2h with the led shining above the drop and half battery depleted, I turned it off and called it a day. The resin would stay quite the same rubbery feeling.
Today, I went to investigate why...
The resin needs a wavelength of about 380nm to 390nm to start curing. The shorter, the best. The supposed to be UV led is nothing more than... a violet led!! It must be some were in the 420 sweet spot!
I've also tried to figure out if a BluRay laser is strictly 405nm or if it has some range, and I think I've found they create an wavelength range from 390nm to 420nm and I find it somehow satisfactory.
But I'll have to postpone this experiments as the BluRay laser diode, focusing lens and driver might take a while to reach my hands!
I hope I can then post the rest of this story and it turn out to be an massive success!!
Until then, it is a normal fail...

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