I’ve got a UV flashlight for curing, but I’m worried about my (and my roomate’s / guests’) eyes, despite owning protective eye-wear for when I switch it on.
I noticed that the Titan 1 kickstarter includes an option to just buy their curing-box; but it’s in the 390-395µm range, not the 405µm of the Form1. Do you know if these lights (20 W total) will help to cure the resin anyway?
Failing that, do any of you have good suggestions for post-print curing solutions that don’t involve visible UV in my room, nor require my direct attention?
Resin photo initiators are sensitive to a range of wavelengths in the spectrum. Lasers that emit at 405nm, like the one in the Form 1+, are inexpensive due to widespread use in Bluray players and the like. Using a 390-395nm wavelength cure box (or any cure box in the UVA range –– 400 to 315nm) is good for post curing our resin. I often use this one: http://www.amazon.com/Acrylic-CURING-Light-Thermal-Spa/dp/B0047PSV14/
I’m actually building one right now, because I could not find one around at a reasonable cost, and have assembled a complete parts list for it. My plan was to complete it, and post pictures and a how-to on this forum if you can wait a few weeks until I get around to finishing it (waiting on a motor PWM speed control…)
Total cost for parts is right around $100USD. It has 600 UV LEDs in the 395-405um range, outputting ~40w total, has a speed controlled motorized rotating acrylic platter so the parts get evenly irradiated, a microswitch controlled door so the lights get shut off when the door is opened, level adjustable feet, and it’s sized and designed so the Form1 sits on top of it (so you can level it as well) so it does not take up any workbench space. It’s fairly cool.
heh - yeah. a little mission creep I guess to an extent. It began simpler (as a box made from 1ft square mirror tiles), but reading a bit, mirrors to do UV well are not cheap, and these tiles would actually not be very efficient for UV. It turns out that a glossy white paint is pretty good at reflecting UV. The cheap LEDs I’m using are in a continuous 5m strip, so I’ve spiraled them in (parallel to front at bottom, angled up and back on right side, parallel to front back across top, down and back on the left side), like a funky screw thread, front to back of the inside of the MDF box.
It has a door, and the hassle of putting lights on the door, plus the convenience of just spiraling them in (and not cutting the strip and wiring it all), made me opt for that design. Originally it just had an acrylic shelf, but the light intensity from the front and back would not equal the sides and top. I thought that was probably not the best thing. I found a small simple gearmotor on ebay new for $12.00, and a PWM controller for $5, and figured why not? So it has a variable speed rotating platter.
First of all, the Sun will kick this things ass and not even bother to take names, but this will cure the entire part slower and more evenly, which if my hypothesis is right, should reduce part warping during cure. And, it’ll work in the rain and snow
So here’s a quick video and a couple of pics of the (mostly) completed curing box. If I have time I’ll try to get a more comprehensive post on the parts, how it’s made, etc.
Wed Nov 19 00:57:22 EST 2014
edit: sorry, but I had to disable the link, as I was being pummeled by Chinese-based IPs.
It reminds me of a microwave. I wonder if you could sell them? Maybe give it an egg-timer like dial that you see on convenient-stove microwaves. It looks like you already have a door safety switch. The turntable could go a fixed speed. Just a few thoughts. It is awesome how it is too :D.
hehe - yeah - thought about that. I kinda kicked myself for not just finding and hacking an old microwave, but one of the goals was to keep the same exact footprint and look-n-feel as the Form1, as my space is extremely limited. As for the timer, yeah, thought about that as well, and hunted for one too, but it was already getting over the top and good electromechanical timers I could find are kinda big. I couldn’t easily fit one. Next, it would be an arduino, with a fiber-optic camera and ‘doneness’ sensor that wirelessly sent updates to my desktop…
One thing I learned in the process of organically growing this, is that I would not make it the same next time. First, I would probably make it a bit taller and put in a false floor for the motor and and panel wiring, and put the control panel across the bottom. Now, the motor drops a bit out the bottom in another tri-bolt pattern ventilated motor-mount like you see in the images. Behind the back wall you see in the images is the 12v power supply and the motor PWM controller. The power supply ‘brick’ has a green LED showing power is active, so I pulled that light up front with an acrylic light-pipe you can see at the top of the panel (but it’s pretty dim by the time it gets up front though…). The plan was to to have aligned light-pipe stubs through the door as well, to show the toggle and power lights when the door was closed, but I have real work to do
-C
edit: re: selling them: how much would you pay for one?
How about a bathroom fan timer? I believe they are just a switch on a delay with no power needs. They look good and are small enough to fit in an area beside the door. If you plan to sell them definitely choose a LM555 timer chip for the PWM vs the Arduino. Another idea is an orange shielded window in the door like the hood of the Form1. You could have some fun styling this like a Form1.
I don’t know what I would pay. In the winter post-curing can take forever. In a cloudy week I could hire it done faster, which defeats the purpose of having a $4k print setup. I would pay a fair price.
