Resin + Laser Pointer = Awesome Glue!


#21

@Clay Cowgill + All

I’ve picked up a few Chauvet LED Shadow blacklights to use as a post-cure setup.  You may want to check them out.

http://www.chauvetlighting.com/led-shadow.html

Mine haven’t arrived (hopefully in the next day or two), but once they do I’ll post about their effectiveness.


#22

I’ll be interested in hearing the results!  We had a commercial 3D haunted house last year, so I built all the LED UV lighting for it.  I ended up using just a couple ~1W UV LEDs every couple feet instead of the panels of the smaller ones.  (The Chauvet panels have 192 LEDs, but they’re 20mA/ea, so that’s about 3.25W.  That can be done with just three of the bigger 1W LEDs and is in theory a similar amount of output.)


#23

@Clay Cowgill

The LED Shadows arrived today and I set them up in a triangle position aiming down and towards each other for coverage.  I put a small model in the middle and based on my tests at each 30 minute increment, it looks like it achieved max cure level in about 30 minutes or less.  It was only a small model that wasn’t very dense, so I’m going to do more testing.

I purchased them for the large coverage area and so I don’t have to assemble arrays myself. I’m sure you could probably achieve the same effect with individual LEDs and it cost a decent amount less.  I have access to a Chauvet dealer, so I get them at a slightly cheaper price.

So far, I’ve liked the results, but I’ll test more prints and do my best to record how long it takes to fully cure the items.  I created some brackets to hold them where I want them and they are currently printing.  They are a bit bigger, so they’ll be a good test.


#24

I’m looking for protective eye wear but so far the experience has been confusing because of the broad range pricing and various types of protection. Also, I’ve found a few products that I feel might be questionable in quality and effectiveness.

Could somebody educate me on this topic and perhaps recommend a product. I’m specifically looking for reasonably priced protective eye wear for purple lasers.

Thanks in advance for any helpful information.

G.


#25

Hi Greenlaw,

We had been using red laser safety glasses in the office specifically because they advertised protection at 405 nm wavelength (which is the laser light we use). The problem is that they block so much other light that it’s hard to see what’s going on, so you find yourself lifting up your safety glasses to see what you’re looking at, which obviously limits their effectiveness as safety glasses 8)

If you search 405 nm laser safety glasses you’ll get red, orange and green options, which can be confusing. Orange allows you to see the best (which is why we chose it for the Form 1’s cover :slight_smile:

We’re using these orange ones:  http://www.amazon.com/Uvex-S1933X-Eyewear-SCT-Orange-Anti-Fog/dp/B000USRG90/ref=sr_1_1?s=hi&ie=UTF8&qid=1376402994&sr=1-1&keywords=uv+laser+safety+glasses

They block the laser (although they don’t specify 405 on the Amazon page). You can also get a 405 nm laser pointer for gluing as Martin said (fixed link:  http://www.amazon.com/Blue-purple-Laser-Flashlight-Paper-Money/dp/B008O2DETA/ref=sr_1_2?ie=UTF8&qid=1379450622&sr=8-2&keywords=405+nm+laser) and also use it test any glasses you buy (just NOT while wearing them!)

-Safety officer!


#26

Jason,

Thank you very much for that information! That was very helpful–you explained so much about what was puzzling me. :slight_smile:

G.


#27

You’re welcome!

I forgot to mention those orange glasses I linked to don’t fit comfortably over eyeglasses for some people.  If you’re going to be wearing glasses under your laser safety glasses, you may prefer the larger style ( http://www.amazon.com/Uvex-S0360X-Ultra-spec-SCT-Orange-Anti-Fog/dp/B003OBZ64M/ref=sr_1_2?s=hi&ie=UTF8&qid=1379456788&sr=1-2&keywords=uv+laser+safety+glasses)


#28

Cool! I do wear eyeglasses so thanks. :slight_smile:


#29

I’ve been using a UV LED flashlight, I’ve found it hardens the resin within seconds and can do a much larger area

(also safer) and low cost off the shelf solution.

I know it’s not quite 405nm but it it still works well also its a blanket cure so you know all the area will have been affected.

SODIAL™ 41 LED Professional UV Inspection Flashlight 395-400nm Ultraviolet Spectrum

http://www.amazon.co.uk/gp/product/B009VW0HTM/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1


#30

I am looking to make a box to cure prints in ?

Found these ? are they overkill, will one work fine in a 12x12x6 box ?

not sure which wavelength will be better, 385-400 or 400-410

Thanks


#31

The lower wavelengths should be a little better I think. If you haven’t worked with those high power LEDs before you will want to heat sink them (so mounting to a piece of aluminum plate, or an old PC CPU heatsink) and be sure you have a constant current LED driver.  (LEDs are current mode devices, so basically they don’t care about voltage as much as current-- for these 10W ones you essentially need at *least* ~10VDC for them to work at full power, but the current is the important part.  So for example, you could have a 12V power supply no problem, you just need to make sure that the supply won’t provide more than ~1A of current at any time.  Even a fraction of a second connected to a supply without current limiting will fry the LEDs.)

For easy-- something like this would work fine to power one of those 10W LEDs (and you couldn’t build a good current limiting supply from parts for less!) :

http://www.ebay.com/itm/10W-Waterproof-Constant-Current-LED-Driver-AC110-240V-to-DC8V-12V-1A-for-10W-LED-/281160157490?pt=LH_DefaultDomain_0&hash=item4176738932

Remember too that true UV light is outside of human visual response, so a ‘UV’ LED with a suitably low wavelength  (say, 385nm) will actually appear to be dimmer than something running at the same power but longer wavelength-- like a 405nm LED.  (You will ‘see’ more of the purple light at 405nm.)  That can be a little dangerous because the UV is still present and is radiant energy even if you can’t see it very well, so if the LED looks ‘dim’ don’t go holding it up to your eye for a closer look.) ; :wink:


#32

Just to clarify:
if 1mW= 1, then 200mW = .02 (less?) in regards to output power?
I have tried a UV inspection LED flashlight, but it doesn’t seem to do anything.
It is rated at 395nMm. Not sure about the power output.
Thanks.


#33

1mW = .001W. 200mW = .2W… Generally UV sensitive stuff cures better at shorter wavelengths, but that may not be the case with the FormLabs resin, as it’s designed to be cured with a 405nm laser. I’ve also found an LED ‘blacklight’ (unsure of the wavelength,) to not do much.


#34

cool. you would have to wear laser safety goggles while you have chosen high powered blue violet laser. The UV laser light is very special. I only use very low powered 5mW blue violet laser before. I get my laser pen here:
http://www.berlinlasers.com/5mw-blue-violet-laser-pointer
It seems quite expensive. Your ideal is extremely nice.


#35

The 405nm laser pen links on Amazon aren’t valid anymore - could someone update the suggestions?

In general, what is the optimum power level for a 405nm laser, to quickly (few seconds) cure the resin? From what I can gather, 5mW is too low, and 100mW might be too high (smoke producing).


#36

I use 100mW laser pointer, it dours produce a very small amount of gas/smoke bit so little as to be inconsequential.


#37

Cool - thanks for the quick reply. Where did you get your laser pointer?


#38

EBay I think, about £35.


#39

Have you ever heard of “5 second fix”? That is what this is. It’s a pen with a tube of UV reactive bonding agent at one end, and a removable UV LED light at the other. You can get it at Walmart in the “as seen on tv” isle for $10.

It’s totally not as fast of a cure time as they say it is, but it does work pretty well. If anything it provides a nice key fob size UV light.


#40

I think the LED that’s included in those UV glue kits are relatively weaker than they could be. So I’m building up my own version with a 2W UV LED, and it really does completely solidify the Formlabs resin in less than second - it’s pretty impressive!

I thought about getting a UV laser, but finding a quality version with enough power, say +100mW, seemed dodgy. Plus, the tiny spot produced by the laser requires you to “paint” larger areas, which in turn raises the risk of reflecting the laser light into one’s eyes - so now I have to buy and wear safety goggles every time I use the laser.

There are also high power UV flashlights on the market that don’t require safety goggles to use, but they produce too wide of a beam and their ergonomics aren’t well suited to the smaller scale of the Formlabs UV gluing workflow. You have to hold them like a, well, flashlight, rather than a penlight.

So, after all that I decided to just design and build my own - I do have a 3D printer after all :slightly_smiling: