Budget UV Cure Box (Jar?)

Projects & Prints
1

So here’s my budget UV curing box (or in this case, Jar) project.

Parts required:

  1. One roll of Duct tape or similar tape (a mostly-used-up roll would be enough, so at most a dollar or so worth of tape)
  2. One suitably sized clear lexan/glass/acrylic container (I bought this one at Bed, Bath & Beyond for $19)
  3. One string of near-UV blue 405nm 12V LEDs (I bought this one at a local electronics supply store for $20)
  4. One roll of Reynold’s Wrap or other shiny metallic foil (cost would be pennies if I hadn’t “liberated” some from my Wife’s supply in the Kitchen)
  5. One 12V power supply (had lying around but a suitable one can be bought at a place like Radio Shack for less than $10).

Start by tacking one end of the LED string to the bottom of the jar and then spiral the string around the jar as many times as it takes to use up the entire string of LEDs. Keep the tension fairly high as you wrap the LEDs and make sure the LEDs face inward. Don’t worry about spacing between wraps, once you’ve wrapped the entire LED string and tacked the other end down you can slide the wraps up/down to space them fairly evenly.

Then, tear off a sheet of foil sufficient to wrap once around the outside of the jar.

Wrap said foil around outside of jar (shiny side in). Use more Duct Tape to hold things down as you go (it helps to tear off a bunch of smaller pieces you can use, before you actually start wrapping things).

Outside view

Inside view

Then, because Aluminum Foil isn’t very “robust”, wrap the entire thing in some additional Duct Tape

Then, put some Foil in the lid, too.

Then, attach a 12V power supply and turn it on (at 24 Watts, this LED string needs 2A, I’m using an old 12V Switching Supply I had laying around, but any 12V supply capable of 2 Amps would work, which includes many wall-wart type supplies).

Ooooh! See inside! I can imagine they have something at CERN that looks like this when it’s powered up…

And a picture of a part getting all UV irradiated and fluorescing to show there’s a good amount of light hitting all surfaces. Looks like it’s in a psychedelic scanning electron microscope. Cool!

The part came out looking to be completely cured after about an hour, though I didn’t do any careful timing I suspect it would have been fine with less time.

The label from the bag of LEDs

And the label from the container/jar, which you can see is more than enough for the build volume of the Form1!

10 Likes
2

Oh man! That looks a LOT like the “blu-spin” curing cabinet I designed! Except mine has a turntable.

3

My super-advanced “Surround Lighting” technology does away with old, outmoded technologies like turntables! :smiley:

5 Likes
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I guess one of us should have patented it :D. My lights are in the same configuration, but I re-designed with a turntable because I was getting slight warping without it. Now they come out perfect. I wonder why it took an hour? Did you check it after 10 minutes?

1 Like
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I really like how simple this is. Nice job!

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Thanks. It’s about the bare minimum of parts, if you want to make something large enough to take the largest practical print size…

I guess the only thing I should add is that, when choosing the container you intend to use (be it round or square or rectangular) be sure that it does not have tapered sides. The sides need to be square (or darn close to it) to the base or when you wrap the LEDs around the container they’ll be a lot harder to space evenly. They will slide down easily in the direction of the narrower end of the taper, and not at all upward in the direction where the taper increases… I don’t think the size of the container matters a whole lot. Obviously a larger diameter container will have fewer wraps/rows of LEDs. But my prototype for this used a Tupperware cake box, maybe 14" in diameter and opaque, not transparent, and it worked just fine. No value to be had in making it bigger than it needs to be, so 8" is about ideal. But it’s not required to be…

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It was still a bit tacky after 10 minutes. It probably needs less than an hour, I was just too lazy to invoke the scientific method. I left a test part in it overnight, and the cure was almost like Lucite. The part took a significant bending stress (much more than what I’d have expected an ABS print to take) and then snapped/fractured like glass when it finally broke. I’m pretty happy with the strength of the cured resin. Looking forward to experimenting with the flexible stuff, when my shipment arrives!

8

Fantastic Tip and tutorial…

Its Great and very cheap and easy to do.

Thank you

9

Need to find a good online supplier for the LED’s.

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Yeah. My problem as well. Most of the online options are overseas, China or other asian locales with long ship times. Luckily an electronics supplier an hour away here in Massachusetts had what I needed, that’s where I bought the LEDs whose label appears above. They had more hanging on a peg in the walk-in-store portion of their business. You could use that label information and order from them over the phone and probably have a roll of LEDs before the end of the week even with standard shipping… YouDoIt Electronics

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http://www.ntepartsdirect.com/CGI-BIN/lansaweb?wam=WKWSEARCH&webrtn=search&ml=LANSA:XHTML&part=CEP&lang=ENG

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Yep, that’ll work! :smile:

13

This UV cure lamp works great for $40. No cabinet required. It will cure a 1" dab of liquid resin in under 10 seconds. I was going to build a curing cabinet but found there was no need to make it a project since I could spend $40 and be finished.

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I looked at options like this, but either you don’t get 360º coverage in the case of this lamp, or it’s not big enough for a larger print like in the case of a Nail Polish curing box. The idea behind my “design” is that you drop a part in and walk away, no rotating required, and it’s large enough for the printer’s maximum print size… It’s a little more than $40, but not a lot more.

15

Here’s another convenient thing you can use my curing jar for… the IPA that is used to wash down the prints gets cloudy with resin after a while and needs to be replaced. That’s pouring a lot of otherwise good IPA down the drain (or your chosen method of disposal) just because it’s got a lot of uncured resin in suspension. It turns out, the plastic tubs that come in the cleaning kit fit perfectly in my 8" jar. So I put a tub of IPA that’s had maybe 10 prints washed in it in to the curing jar, just dropped the whole tub, lid and all, right in. An hour or so exposure, and my IPA is clear again except for the thin layer of cured-resin particulate sitting at the bottom of the tub, that I can now easily strain out with a rag! Yay!

Looking in to the cured tub from above. The gray mottled “dust bunnies” you see is the cured particulate resin aggregating at the bottom of the tank of IPA.

1 Like
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One of your images reminds me of a collapsible camping cup. I have a similar idea: I am looking for a large cylinder to fasten/adhere the LEDs in a similar coil form. My idea is to use glass as the base, with rain-x applied to the top. Then, I was thinking of integrating a switch into a handle at the top, similar to a teapot so that when I lift the top (with LEDs), the power goes off. There would be a master switch as well for when curing is night needed.
Thank you for the practical guidance on the electrical requirements. Its been about 22 years since I had a high school electronics course. One question on the electrical, is a resistor needed between the power supply and LEDs? Or is this not needed with a Power Supply? Thanks!

17

It would depend on the LEDs, I suppose. For the LEDs I used, no current-limiting resistor is required, it’s built in to the LED strip. Just hook it direct to 12V and you’re good to go. The strip can even be cut in to segments that can then be used independently. But other LED strips I’ve seen require a driver circuit which means they don’t have a current-limiting resistor. If you aren’t going to just buy the ones I’ve used, be sure to check to make certain that no additional driver circuitry is required and you should be A-OK.

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I anybody in Europe manages to find suitable led strips for this DIY curing jar … let me know. I would love to make it instead of buying a nail cabinet.

19

Hello Francesco,

I also searched for this UV-stripes and found this here in Germany
http://www.leds24.com/flexible-LED-Streifen

Not so cheap but here in EU

regards
Kalle

1 Like
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I decided to get a 5m roll from china. 28 euros with supply included … probably 45 with duty.
Let’s see if they come that they work! There are much cheaper on eBay that that and worth a try (except when delivery time is important).