My third ground-up build.

[chelboed]

My third ground up build:

Finished the host for the single XP-G unit. Both my triple and single have shipped, so I guess I'd better get on the stick and get some anodizing done.

It has a double stepped flat bottom hole b/c the MCPCB is 14.6mm, Tina optics are 16.1, and the Lens and O-Ring are 17mm. Snap ring is 19mm.

This one uses a snap ring to retain the guts. I'm going to get a less obtrusive ring...but this was all I had available at the moment.

Size:

And compared to the MS:

Now I gotta build a mount for the single.

 

[ibbleobble]

Man, those are beautiful. You're an artist. I wish I cold do that. Do You sell your work?

 

[rayman]

It's getting better and better :twothumbs. All your wokr looks great.

rayman

 

[chelboed]

Man, those are beautiful. You're an artist. I wish I cold do that. Do You sell your work?

Probably will. When I get it all ano'd and the guts installed...I'll throw out a line and see if I get any bites.

 

[chelboed]

I'm done with the single and working on another small triple with a snap ring retainer instead of the facecap:

The 22.2mm triple (walls are 1mm thick and the snap ring section is only 0.5mm (yikes!)

 

[chelboed]

Sending these off to get anodized...

 

[chelboed]

 

[JB01245]

The blue looks nice! Noticed that you/they didn't plug the threaded hole(s). You will probably have to retap them and remove the anodize from the threads to get your fasteners to work.

Did you account for the anodize build up on your tight tolerance inner diameter features?

 

[chelboed]

I wasn't sure how thick it would be...I gave a little extra, but if I have to sand it off the inside...so be it. Won't hurt anything to get rid of the ano on the inside. There won't be anything electrical contacting the alu.

Retapping the holes will be a snap.

 

[BrianMc]

BTW. I like the blue. It'd go nice on my blue bike.

 

[aurum]

Wow ... I like the blue color

 

[chelboed]

Almost done:

 

[alpg88]

wow, :twothumbs

 

[chelboed]

Obviously compared to a P7 like the MagicShine, this light doesn't put out quite as much...but when you consider that it's about the size of a quarter:lol:

F4
ISO 100
Daylight
6"
Just for a reference...here's my old MagicShine Beamshot:

Here's the L31 single XP-G with a 20mm Carclo optic:

When I let it go for about 20min, it went from 34 ambient to around 61C. I turned on my fan on the lowest setting to mimic a leisurely pace through the woods and it quickly dropped down to 44C and stayed there. The normal operating temperature for this LED and board is somewhere between 60-80C...therefore, I have RAWK'd a housing that's small enough to lose when you're 3 sheets to the wind...but still big enough to keep it far below any critical heat. It's funny...when you feel it at 60C (140' F)...it "feels hot"...but the LED is rated up to 150C (302 F) and the board has a "smart shut-off" at 120C.

No chance of this one getting too hot.:thumb:

GITD:

Can't wait to get the triple under way!

 

[brad72]

Beautiful little light. Fantastic work.

 

[chelboed]

Thanks man...I'll try to get a triple done this weekend. I used a 2s RCR's for the battery pack which should give about 1-1.5hrs...it's so dang small though....funny! I'm still on the fence about whether or not to do the square or Hex next. We'll see.

 

[BrianMc]

Nice. Good temp.

I'd say you are close to about as small an interface per watt as you should go and keep the LED in the 80-90%+ of max efficacy range.

Beam looks good. Proof is in the riding.

 

[brad72]

I'd say you are close to about as small an interface per watt as you should go and keep the LED in the 80-90%+ of max efficacy range.

From memory the ideal amount of cooling is 1 square inch (6.45cm) of cooling per watt of led output. Does this sound correct?


So Chelboed, when is the maiden run out on the trails?

 

[BrianMc]

From memory the ideal amount of cooling is 1 square inch (6.45cm) of cooling per watt of led output. Does this sound correct?

That's more a rule of thumb and derived before the higher heat transfer rates of the XP-G. I have 10 watts of XP-Gs (3 x 1 A) with 7 sq inches of air contact and NO FINS. EL34 runs over 11 watts of P7 with about the same area. About 0.7 sq inch per watt consumed. 44-45 C in dead calm 22-23 C air. Luke warm on rides at full power at 30-35 C ambient. However, at 1 amp almost 2 watts that the 3 XPG R5s use become light, so there is about 1.1 square inch per watt of heat output.

So, yeah it's a guideline, based on a lot of work with older LEDs like Luxeons. YMMV.

 

[chelboed]

Hopefully I can get out to the trails soon.

Check out the "My Second Ground Up Build" thread for pic's / beam shots of the triple L332 board. That one's done too.

It def. warms up quicker than the little one, but I think it will stay cool. I hadn't really charged my battery pack prior to the build, so I couldn't do a good "heat test". Soon.