EC11 MELD update with LASER! The ultimate small EDC

I had to crack open my recently-finished EC11 MELD light to fix a switch problem, so I decided to take the opportunity to cross two goals off the list: stop being annoyed by the unused hole in the reflector (from the red LED in the stock setup), and finally add a long-overdue feature - LASER!

I had been wanting to try and get a laser into one of my MELD lights for a long time to truly make it the ultimate EDC light, but I always got stuck on the issue that the smallest laser assembly I could find was 6mm in diameter, too large to drill out the reflector for it. Finally I realized the hole in the reflector doesn’t have to fit the module, just the beam!

Luckily the EC11 has a lot of space in the driver cavity once I replaced the driver with MELD-X, so I could fit this cheap 5mW 6x11mm red laser module down below the LED board. I had to do some surgery on the laser module to isolate the electrical connections from the housing, then I drilled hole in the LED platform for a press fit:

The back of the module just clears the driver when pressed in just below flush with the LED board platform:

MELD-X doesn’t have an output set up for this sixth emitter (yet), so I had to tack a small wire to an unused pin on the microcontroller. This pin controls a small FET to turn the laser on and off:

Now there are even more wires connecting the driver to the head - nine of them:

I did a functional test of the laser in situ:

And drilled a small (2.5mm) hole in the LED board to allow the beam to pass through:

Thermal paste was carefully applied so that it wouldn’t get on the laser’s lens, and then I reassembled everything as normal, taking extra care to align the reflector with the laser.

I added the laser to the UI by putting in a sort of a mode group with the UV, similar to how I handled the multiple UV wavelenths in project EMERALD. Here’s a quick demo of how the laser fits into the UI:

I’m currently looking into fitting a green or high-power blue laser into my next EC11 build…

What do you guys think? Is this worth adding to the standard MELD-X offering? Would anyone else want to build this feature into their multicolor lights?

this is unreal! amazing.

A laser is a fun extra feature, I’m sure that there is folks out there (with cats at home) that will build it in :slight_smile:

This is crazy. I’ve got one of your drivers sitting here that I haven’t had time to use yet. I may have to send it back to you to have the newest version of your firmware flashed on it.

…and you would know I sold my EC11 a few weeks ago.

Great thinking :+1:

Awesome idea, I bet the Chinese sellers come up with one soon now the idea is out! Fingers crossed…

… but of course I would like a laser added, however, don’t stop there :wink:

Well I guess I’ll be ordering yet another MELD board. I’ve wised up though. I’m going to wait a while so I don’t miss any more cool updates.

Great job tterev3!!! These are really amazing features.

Awesome mod! Maybe can try some green lasers for even more power.

I doubt this will end up being a standard firmware feature, I think it’s too specialized. That said, I would be happy to flash boards with this version if anyone wants to build something similar

Ok. I’ve been wanting to build a laser but I feel the same way about lasers that I felt about leds when I first started. Now with leds I know exactly what I want and what to stay away from. Mostly I know what price tags are worth the product. With lasers I am still in the dark;) same with uv. I want a good uv led but I’m afraid I will be let down if I order a budget option. So I haven’t pulled the trigger on any uv leds yet. You linked to some nice smaller ones earlier or maybe a different thread? But I would like something a bit more powerful combined with rgb in a quad optic or similar setup.

I just can’t seem to be practical even if I try reeeaaally hard! :slight_smile:

An update on my EC11s with lasers:
I had continued switch problems using the stock switch board, so I finally did it right and made a custom switch board:

And held it in place with a 3d-printed spacer:

These new switches have a much better feel and give more reliable signals. The other issue this setup fixes is decoupling the switch board from the driver, which helps some aligment issues as well as makes the driver removable in case I have to open it up again.

Once that one was working well, I got another EC11 in the mail and decided I had to go with a high-power green laser this time. The issue with green lasers is that they require 2 stages (crystal frequency doubler plus collimation) instead of the single stage for normal solid-state lasers. This means that the shortest green laser module I could find was about 17mm long, too high to fit in the EC11’s driver cavity. (side note: the smallest laser modules I’ve found are in single-AAA keychain lasers I get on eBay. You also get lucky sometimes and get higher power units that the sellers can only advertise as 5mW because of FCC rules - the ones I used here I estimate are around 75mW of output)
I came up with a crazy plan to try to fit this module in. By separating the two stages and adding a piece of a FSM (first-surface mirror) pulled from a laser printer, I came up with this 90-degree laser assembly that gets the collimating lens at the correct distance:

The transparent red piece is my 3d-printed frame, yellow is the laser’s first stage, blue is the FSM and collimator, purple is the MELD-X driver board, and green is the lower section of the EC11 housing:

I also had to file off the edges of the laser module. I assembled everything into the printed housing:

I only half expected this to actually work, but when I got it assembled and did some tweaking with the mirror, it works!

I drilled the aperture for the beam, then arctic-silvered the exposed brass on the laser module to the LED platform for heatsinking. I modified the MELD-X driver to repurpose one of the regulators for the UV channel to run the laser diode, so this and the UV now run at 350mA and there’s no floating regulators. The head of the light is now ridiculously full - there’s only 1mm between the top of the driver components and the laser module. I even had to add a spacer ring on top of the driver board to drop it down slightly:

After assembling everything else as normal, I have a working EC11 with RGBWUV + green LASER!

Are you serious? Wow, great job! I almost expect you to make another light that houses rgbwuv leds + rgbw lasers.

… I’m in for one!

Wow. Amazing effort and abilities.

Brilliant!

I almost pulled the trigger on a deal for the ec21. Thinking I could use a laser in place of the uv led. I probably would have purchased it if I wasn’t afraid of the head being glued. I really hate flashlights with plier marks on them!

Edit: I spoke too soon. The deal was still good. :wink:

Anyone have a link to a laser module that is known to have higher output than the rating? 100mW or more would be nice:)

The glue appears to be random - I have opened four EC11s and only two were glued.
Here’s the laser I’m using: Look at this on eBay http://www.ebay.com/itm/152203282905

Thanks tterev3! I know I’ll need to do some fabricating. I’m not afraid of cutting, drilling, filing and gluing but I’m not experienced with ladies lenses. Will I need to mess with the optics as you did? I don’t have access to 3D printing so I will need to be creative with all securing and positioning.

Yes, to fit green you’ll have to get creative. You only have about 11mm of height (if you take up the thickness of the LED platform as well), and the smallest green modules are about 17mm tall. Red can be done more easily.

On an unrelated note, I had access to an x-ray machine at work today so I got this image of my EC11 with the green laser: