MC-E Light (Beamshots added!)

[StevelKnievel]

I finally got around to making a light with my sample MC-E!:rock:

Specs:
- Series wired MC-E K bin (370lm @ 350mA)
- Taskled Fatman driver set to 700mA
- 2" long x 1.25" dia.
- Modified IMS20 reflector and a UCL glass lens
- Old Turbocat handlebar mount
- Batteryspace 7.2V 4800mAh Li-Ion

I didn't have any waterproof switches handy so I didn't use a switch... one less thing to fail and it helped keep the housing small. I finished the light last night and took it for it's maiden voyage on our Tues/Thurs group ride. The beam pattern is good with a large amount of flood and a big soft center hot spot.

Here's some pics:

Beam shots!
Both of these are taken at 1/4sec F2.8 using a Canon A620. The lounge chairs are at 15' and 30', the white lattice thing is ~60' away from the camera.

K-bin cold white MC-E unknown tint, Fatman, 700mA, modded IMS20 Reflector:

For comparison here's my helmet light:
3x R2 WH tint, Fatman, 900mA, Cutter Medium MR11 optic:

 

[wildwood]

Re: MC-E Light

that rocks dude
beam shots soon i hope

 

[TONY M]

Re: MC-E Light

Super cool light!
Awaiting beamshots...

 

[KrisP]

Re: MC-E Light

How warm does it get?

 

[StevelKnievel]

Re: MC-E Light

It stays just warm to the touch while riding, but in still air it will get pretty hot in about 5 minutes. This one is definitely right at the limit of heatsinking 10 watts! :devil:

 

[trout]

Re: MC-E Light

Steve you have got me worried now as you know I am planning this 3 mce beasty

and also I am making some single MCE lights for riding buddys and I had just finished this housing the top one

which is very similar to yours when you said it is at the limit for heat removing I started another housing with more fins but thinner so I ask the collective brains here am I right to go with more fins but less mass for better heat removal

Very nice light you have made there
Have you ever cut the grass since you last beamshots a year ago

It stays just warm to the touch while riding, but in still air it will get pretty hot in about 5 minutes. This one is definitely right at the limit of heatsinking 10 watts! :devil:

 

[Hack On Wheels]

Sweet lights!

I have some questions about the MC-E and heat, thought I might as well post in here instead of starting a new thread. I'm planning a dual MC-E build, planning to not run the ME-C dies ever at over 700mA, and I've modeled up a housing in NX5. The catch is that as happy as I am with learning how to use NX5, this housing (aluminum) is going to weigh 318gram, plus more once I add a backplate, internals, and other bits.

I'm trying to leave 2mm thick walls minimum at all points to make the milling easier and keep it sturdy... I'd like to be able to shave weight, but I don't want to lose my heatsink fins, and I don't want to flip to the other extreme and not have enough mass and surface area to dissipate the heat. Just how much heat do I need to worry about? Also, does it matter how thick the section is that the MC-Es mount to? If I can make the mid section thinner, leaving 2-4mm only for the LEDs to mount on, I could shave a bunch of weight...

Anyways, long post, but any help/suggestions would be great!

 

[StevelKnievel]

Re: MC-E Light

Have you ever cut the grass since you last beamshots a year ago

Hahaha!I have cut the grass a few times... but the summer in Florida grows it back as soon as I'm done:hairpull:!!!

Trout those housings look nice! As long as you can distribute the heat to all those fins I think that more & thinner fins is the way to go. I'm happy with the cooling on my light, but I also know that I have turn it off if I'm stopped. I think if I make more of these housings I will make them 1 3/8" OD with taller fins instead of 1 1/4" OD. That change alone will net 5 square inches more surface area.

Hack on Wheels-
NX5 , cool! That's a pretty potent software suite! If you want I can take a look at your model and let you know if I see anything that could lighten it up... but 300g sounds about right for a housing that has to deal with 20+watts in still air.

-Steve

 

[Hack On Wheels]

Re: MC-E Light

Hack on Wheels-
NX5 , cool! That's a pretty potent software suite! If you want I can take a look at your model and let you know if I see anything that could lighten it up... but 300g sounds about right for a housing that has to deal with 20+watts in still air.

-Steve

Steve,

Yeah, it sure is a powerful program, I have a lot to learn! That would be awesome, would you want the part file, or some renderings to look at? It is far from being finished at the moment, still some through holes to put in for wiring, some threaded holes for the backplate and the faceplate need to be done as well. One of my goals is to make it waterproof, with an IP67 rated switch (illuminated for status LED option), a cable gland, o-ring/lip sealing for the backplate, and gasketing (need to look into materials for that) for the front plate (flush fit). Lots to do still on this model and as I go along, I keep realizing how awkward some of the techniques I've used have been. I was actually thinking to have this as a helmet light, and of course only run it at full power when I'm going downhill fast... at 350mA, this would already be rivaling or even beating my triple R2 light!
Haha, I guess I'm caught between trying to over-engineer (sturdy and waterproof), while wanting it to be light and super bright... something has got to be compromised, eh?

 

[trout]

Hack on wheels
any chance of a picture or 2
that sounds a weighty housing .
as the top one in my pic weighs 68 gms and is ready to accept
a MCE / optic / and maxflex .

and from other quad builds I have
done will keep cool as long as it keeps moving + you can use the thermal functions on the Maxflex to protect the whole light

 

[Hack On Wheels]

Hack on wheels
any chance of a picture or 2
that sounds a weighty housing .
as the top one in my pic weighs 68 gms and is ready to accept
a MCE / optic / and maxflex .

and from other quad builds I have
done will keep cool as long as it keeps moving + you can use the thermal functions on the Maxflex to protect the whole light

Yeah, it definitely does seem weighty! I should be able to get some pics/rendering of the current stage of the housing shortly. I'd love to get it lighter, but I'm trying to make it pretty easy to build, solder, take apart, keep watertight while being easy to disassemble, etc... and to be honest, I don't really know what I'm doing, I'm just having fun with this more than anything.

Maybe I should make a fat light for the bars and make a single MC-E light on the lathe like yours for the helmet? I can't help but want to run a dual MC-E light on the helmet though, even if I can only run it at full intensity when I'm going downhill, and downhill fast... :devil:

Haha, this light stuff is way too much fun!

 

[Hack On Wheels]

Okay, here are some pictures....

A few things to note, I have marked points on the model roughly where I plan to put the bolt holes to hold the front plate on, and the rear housing section on. The rear housing section will slip over the end of this section and I will use an o-ring or some other type of gasketing to have it seal when tightened down. Perhaps I can smooth the corners of the rearmost protrusion for an o-ring to fit around as the 90 degree corners wouldn't work well.

Trimetric view

Front wireframe view

Right wireframe view

Rear angled view

Steve, sorry for the threadjack! Perhaps I should be starting another thread, at this rate...

 

[StevelKnievel]

The heatsinking capability of that housing looks great! Assuming you are going to CNC this or have it CNC'd I would give the whole thing a more oval profile rather than a pure rectangle. That'll shave some weight with minimal loss of surface area. You can also shave some significant weight if you mill one oval pocket for the two LEDs instead of two round pockets. For centering the LEDs you could just put some shallow round bores at the bottom of the pocket that the stars would fit in. You got the right idea making the whole thing out of one piece...I can't wait to see what you end up with!

 

[Hack On Wheels]

The heatsinking capability of that housing looks great! Assuming you are going to CNC this or have it CNC'd I would give the whole thing a more oval profile rather than a pure rectangle. That'll shave some weight with minimal loss of surface area. You can also shave some significant weight if you mill one oval pocket for the two LEDs instead of two round pockets. For centering the LEDs you could just put some shallow round bores at the bottom of the pocket that the stars would fit in. You got the right idea making the whole thing out of one piece...I can't wait to see what you end up with!

Thanks for the feedback!

Yeah, I'm hoping the heatsinking will at least be enough. Actually, I doubt this will get CNC'ed. I don't know how to set that up, and while my university does have at least one CNC machine, I don't think I would be allowed to do that myself anyways. Frankly, if I have any hope of having this light happen, I need to mill/drill/saw/tap/etc. it all myself to keep the cost down. That is why I've avoided fancy shapes, nice curved outside corners and such. It will mostly be drill press stuff I think, with a bit of milling, a few passes to make the hollow in the rear, then the heatsink fins will likely be made with the bandsaw if the width of the blade is adequate. Any suggestions for how thick to make the fins? The LEDs will be on stars and hopefully the Boomerang reflectors will fit in there snugly and I can use them to center the optics. AAA the optics or screw them in?
I was also wondering, how small would be too small for the screws to hold the front plate and back plate on? I've modeled it using 3mm holes at the moment to see how much space I would need for M3 bolts. I've also shaved a bit off the four sides of the housing, put a 1/2 inch through hole in between the LED/Optics holes (your single pocket idea for both LEDs/optics inspired this), and with all said and done... the main section of housing is now 245 grams. Not too shabby, but a bit much weight still for an XC helmet. Anyways, back to puttering on my design and looking into gasketing sheets...

 

[LukeA]

Don't heatsink fins become ineffective at less than 6mm spacing? It was a VanIsleDM thread. That would significantly affect how hot the light gets.

 

[Ducaticorse]

Apologies for the question(s) as I'm just starting to try to get up to speed on the MC-E emitter, but:

Am I correct in understanding that one really nice aspect of the MC-E for a bike light is the ability to use existing boost-driver circuits like in Stevel's light, treating the MC-E like an ultra-compact multi-emitter setup?

Why would one choose a Fatman vs. a MaxFlex2 for this type of setup? (To be clear, I'm not challenging Stevel's choice of driver, just trying to learn!) If I understand George's boost drivers correctly:

Fatman = single current level with potential for an externally-mounted output pot. Smaller (0.8" diameter), cheaper, simple.

MaxFlex2 = UI like the bFlex and wider input/output voltage range, but at the cost of size/packaging (larger diameter), complexity (can be a bad thing) and $$.

From the description and pics, I assume Stevel's light head is like a very slightly overgrown Aleph2 head? WOW that's small! Hence the discussion points about heat dissipation?

Thanks for any help tuning me up!

 

[Doh!Nut]

The Fatman has a current output limit of 16v so matches for single MC-E, It would be easy to get a Hi/Lo switch rather than a pot (easier to use on a bumpy road IMO). I remember that the the Fatman does not go to zero completely.

The real advantage of the Maxflex is all the options of thermal limiting and battery voltage functions etc.

It did cross my mind that you can power three MC-E with a MaxFlex by connecting the dies 6Series 2 Parallel.
You would only get 600ma per string and you would need a pretty high battery voltage to keep the input current within limits, but it is possible.

Nick

 

[robjdixon]

What would be a good driver to drive the m-ce in series?
I would like 2 modes, but i am not too fussed - i would be using a 14v battery pack, so I don't need a boost driver

Thanks
Ps sorry for slight threadjack

 

[gillestugan]

Beautiful machined bike lights I must say!
Regarding the heatsinks I would advice you to make lateral fins instead. It would enhance the airflow through the fins while cycling.
Regarding the cooling capacity. Heavy weight and thick fins means good heat conductivity and gives an even surface temperature over the whole sink, but smaller surface area, so the air can't fool it as efficiently as multiple thinner fins.
I don't think small distance between the fins will be an issue as long as the light is cooled by flowing air.

 

[StevelKnievel]

The fins should be vertical on bike lights IMO. While cycling the heat is easily dissipated even without substantial surface area. It's only when you are stopped that the fins are cooling the light via convection. For convection to work best in still air the fins should be vertically oriented.