XM-L U2 wide-angle light using a NiteRider miNewt housing (first build)
U2 XML wide-angle build using a NiteRider miNewt housing
Inspired by the miNewt upgrade thread by mattthepuppet, I decided my first ever DIY bike light project would be upgrading a NiteRider miNewt light to an XML LED.
During the planning process, I realized that I didn’t want to re-use any of the existing parts for this build (I kept them in case I changed my mind later). I ended up basically building a from-scratch light using only the light housing.
I wanted to spend as little as possible and keep the modifications reversible so I could continue to upgrade/reuse the housing in the future.
Here’s a photo of the miNewt head disassembled.
The internal diameter of the housing is 20mm. I bought a few U2-1C XML LEDs mounted on 20mm bases. I’ll use the extras in my next project (already scheduled ;) ).
XML-U2-1C 320LM 7000K LED White Light Emitter with 20mm Base(3.7V) - $6.59
I purchased a 6x7135 driver (2280mA) to light it.
KD 6x7135 V2 LED Driver 2280mA 17mm - $4.59
While I was browsing on KD, I decided to also pick up a couple of cheap optics to play around with. This is going to be a wide-angle bar light and these (from what I had read) might work better than the stock reflector.
20mm SSC Cross section Aspherical lens - $1.46
20mm SSC LED Optical Lens - $1.41
The optics are quite a bit shorter than the factory reflector (I don’t have the exact measurements with me. If you’d like them, let me know and I’ll measure and respond). This meant that I had to figure out some way to move the XML star forward in the housing; but, I needed to maintain thermal conductivity with the housing.
After much thinking and digging around in my boxes-o-parts I had a plan.
I found a zinc washer that was almost exactly 20mm in diameter.
Drilled out the center to 1/4” to match the heat sink post in the housing (the post extends slightly past the washer when installed). I also transferred the screw hole locations onto the washer and drilled them out so I could mount it securely.
To thermally bridge the star to the housing heat sink mount, I bought a piece of 1/2" aluminum rod from a big-box home improvement store. I made some measurements (which ended up being incorrect – more on that later) and cut off a piece.
I worked it down to the desired height and then flattened the ends so there would be clearance for the screws.
To bond the aluminum puck to the washer, I mixed up a small amount of JB Weld and put a tiny drop between the puck and washer.
I then clamped it up and added some extra on the ends.
Here is the result after curing for a day.
I put a dab of arctic silver on the bottom of the aluminum puck and mounted it in the housing.
I removed the U2 XML star from the test setup and used a grinder to take off a couple of the tabs. This allowed the wiring to route properly.
Soldered on the leads.
Added a bit of arctic silver to the top of the puck.
I now need to compress the star onto the puck and secure it somehow. To do this I found a small aluminum bushing, placed it over the LED (the inner diameter wasn’t touching the business end of the LED), and gently compressed the assembly in a clamp.
Here’s a better view of my clamp within a clamp.
To hold the star in place, I squirted a bit of acrylic/silicone caulk onto a paper plate and used a toothpick to tuck it in between the star and housing.
The optics didn’t come with a holder and I needed a way to ensure they sat against the LED and didn’t “fall off” the edges. I had some nylon washers and I used a razor blade to cut the center out of one to match the LED base. There are various size in the bag (came out of my parts bin); but, I’m fairly certain the washer I used was the size indicated on the bag.
Now the optics sit nicely on the assembly and it’s fairly simple to slip on the end of the housing.
More on my measurement mishap. Where (I think) I goofed is the new optics have a lip on them that is not flush with the end of the optic. I didn’t take this into account when calculating the height of the puck. So, once fully assembled, the optic was a bit loose in the housing.
I wasn’t real pleased with this. And, I wasn’t about to go making a new puck/washer combo. I dug through my bin again and came up with a slightly larger o-ring (came from the spares of a RockShox SID rebuild kit).
Factory ring on the left, replacement on the right.
Now everything fits nice and snug.
DISCLAMER: The driver/switch housing is too large for my liking. I bought most of the odds & ends at a local electronic parts store. I’ll be re-working this at a later date to make it a bit smaller and more weatherproof. But, you gotta start somewhere. Right? :)
To drive the LED, I built a battery pack and modified a charger.
The switch/driver assembly is a small plastic project box and clicky switch. I mounted jacks to fit the plugs on the leads.
To package it together, I bought a cheap camera case and removed the padding from the outside of the case (so I could activate the switch through the case).
Mounting the assembly to the bike was done with a long piece of velcro tie down (double sided velcro). I had yellow and red on-hand. I’ll pick up some black to make it look a bit better.
The velcro is looped through the belt loop of the camera bag and the head tube. I wrapped the remainder of the Velcro around the bag (kept it from wiggling around as much).
And, without further ado, here are the end beam shots…
4 second shutter speed
Daylight white balance
18mm focal length
Using the “diffused” 20mm optic.
Using the “wide angle” 20mm optic.
Control (about 5 min later than first control shot):
I'm sure I've left something out. If you have any questions, don't hesitate to let me know and I'll answer them as soon as possible.
Thanks to all that have previously posted threads. It was your builds/upgrades that inspired me to take this one on. I can only hope someone finds a valuable bit of information in here they can re-use in a future build. :thumbsup:
Looks like really nice results - I'm favoring the diffused optic - it seems to have a lot of usable spill, and seems to reach down range a little better
Originally Posted by marpilli
Well, I threw your HIGH power pics in a gif for you.
Looks like the bike moves a little between shots, and the angle of the light might move too?
In the Wide shot it looks like it has more light on the fence across the street, but I wonder if that tis truly "usable" on the trail. Also looks like it is lighting up the top of the tree and all areas out to the side more, rather than focusing your light forward.
Medium power on the Wide optic looks a lot better in those pics though. If youplan to be running on med. a lot, that might be a consideration.
You happen to have a beamshot for the MiNewt before you modded it?
nice job marpilli, glad to see it all came together in the end! Neat craftsmanship on the head mods, although I'd be tempted to get 2 longer screws and screw the LED/ adapter sandwich down all together.
check out LED-DNA for optics, the 10deg ones I've tried from there are really nice and they offer wider angle ones too.
adrenalnjunky, thank you. I didn't get a beam shot before tearing down the miNewt. I thought about that later and wished that I had. My next project will be upgrading a Cateye Doubleshot in a similar manner (for use as a helmet light). I'll be sure to get a "before" photo this time.
EDIT: I still have the original miNewt LED assembly, leads, reflector, etc. I might try to put it back together (without the housing - just hold it together with tape or a clamp) and get a beam shot in the same location.
There's little doubt I didn't reposition the bars (and the beam) between optic swaps. It was my first attempt at a beam shot. :)
The swap only takes a minute and can be done easily at the trailhead. I plan on completing the helmet light (hopefully will go faster than this project did) and then head out on a short trail with the full setup. Complete a lap, swap optics, and go again. Hopefully that will give me an idea of which one will pair well with the helmet light.
mattthemuppet, thank you also. I thought about extending the screws. But, I wasn't sure where I could get something that small (with a fine thread). I may poke around in the local RC shops and see if they have anything that would work. As with most of my projects, I'm quite sure there will be a version 2, 3, etc. Always room for improvement, ya know? ;)
Very nice. Would be fun to see what it looks like with the stock reflector.
Thanks! I think in matthepuppet's thread he had a before and after beam shot.
Originally Posted by gticlay
If I get a chance, I'll see if I can get one (assuming I don't have to modify the reflector).
Well done Marpilli! The switch box looks a little like a home made explosive device. :D Perhaps the batteries might fit in there, too?
It's just a bit more narrow than the battery holder. After I get done with the helmet light, the first thing I'm going to do is change that box up.
needs this kind of switch for that:
Originally Posted by StiHacka
OK, I took a few more beam shots and was able to change the optics without moving the mount (I clamped up spare handlebars in my repair stand).
However, I didn't realize the camera was askew. I just can't get it all together. :madman: :lol:
It won't win any photography awards. But, it should give you a better idea of the difference between the optics.
Same camera settings as before.
Control (full moon tonight):
"Wide angle" optic - high:
"Wide angle" optic - medium:
"Diffused" optic - high:
"Diffused" optic - medium:
I tried to take a photo of the stock LED beam with stock reflector. Darned thing got too hot before the 10 second shutter timer went off. I was afraid it would be damaged. Mission aborted.