Lumapower LM-301 is a good Cree Host (Pictures missing, new ones on page 2)

[Marlite]

Re: Lumapower LM-301 is a good Cree Host

Engrpaul

Wow, you have moved way up the modder ladder with your great light mod. Lumapower promised a big surprise in 4 days on Christmas Day? Who knows what they have now. They will be pleased for you, modding their light so successfully. The LM 302 is close a 2nd to my JetBeam Mark I as both are white and bright.


Congratulations, Marlite

 

[EngrPaul]

Re: Lumapower LM-301 is a good Cree Host

Erasmus,

I copied a tutorial a few posts up. I am really sorry I didn't take pictures as I went along. The only difference is that the lumapower uses thermal adhesive or compound below the emitter.

Tools and parts I used:

A large flat file is helpful for removing standoff height from the back of the reflector.

A drill and assorted bits to open up the hole slightly.

A dremel with a small conic diamond bit to remove unwanted "lip" at the emitter base.

.001" thick Kapton tape, about 3/8" wide, high temp silicone adhesive.

Pointy needle-nose pliers to back out the pill from the head.

A soldering iron, solder, and desolder wick.

A "third hand" device.

A cree PCB rev 2 from the sandwich shoppe.

Thermal compound (or epoxy) from the sandwich shoppe.

Compressed air to clean up the mess.

Isopropyl alcohol.

Q-tips and low lint towels.

Patience.

And next time, a camera!

 

[easilyled]

Re: Lumapower LM-301 is a good Cree Host

Very impressive - I envy you for your skills

 

[Pumaman]

Re: Lumapower LM-301 is a good Cree Host

LM301 with P4 WH cree(left) vs stock LM301 at 4ft.

now way underexposed. the hotspots are similar, with the cree throwing a little better. but the sidespill difference is huge as seen above.

GREAT cree host. My only request would be a slightly higher drive level on high.

 

[x2x3x2]

Re: Lumapower LM-301 is a good Cree Host

Superb job EngrPaul!
I wanted to do the same for the LM301, but in the increase in brightness signifigantly noticeable? If not, i'll probably save my Q2 for a 3.7V light.

Thanks for the MANY pics too

 

[Raptor#]

Re: Lumapower LM-301 is a good Cree Host

Nice work!
How's the minimag in its flood setting, when used with the cree? And: Wich one do you think is the better thrower.. the minimag cree, or the LILL? How would a Minimag 3 AA Cree compare with the others?

Sorry, lots of questions going thru my head when i think about the possibilitys with the crees.. Thanks for all the pics!

 

[EngrPaul]

Re: Lumapower LM-301 is a good Cree Host

Nice work!
How's the minimag in its flood setting, when used with the cree? And: Wich one do you think is the better thrower.. the minimag cree, or the LILL? How would a Minimag 3 AA Cree compare with the others?

Sorry, lots of questions going thru my head when i think about the possibilitys with the crees.. Thanks for all the pics!

The minimag opened to flood is somewhat ringy but very useful. If it was a 3AA it would be brighter. But still, it would be the same length. :naughty:

The Lill is the best thrower of the bunch. The beam of the Lill can be focused by turning the head. The Lill with Cree is comperable to the Mini-D when it's on high, but more ringy. It's also the same size flashlight in most dimensions.

 

[paxxus]

Re: Lumapower LM-301 is a good Cree Host

EngrPaul, I'm toying with the thought of buying the parts and attempting this cool LM-301 mod of yours (on an LM-302). I have read your very good explanations and I think I can do it, but I'm struggling a little with the "Kapton tape" part of it. What on earth is "Kapton tape" and what is its function? Is it needed?

:goodjob:

 

[EngrPaul]

Re: Lumapower LM-301 is a good Cree Host

paxxus,

Kapton tape is 1 mil thick polyimide with about 1.5 mils of high temperature silicone adhesive applied to one side. It is typically used for masking areas of a printed circuit board for when it is to be soldered in a bulk process (wave soldering or reflow soldering).

It's helpful for holding something in place, just like you would use invisible office tape. But it can withstand soldering temperatures and still come off cleanly.

You don't have to use it.

 

[paxxus]

Re: Lumapower LM-301 is a good Cree Host

Got it, thanks.

 

[paxxus]

Re: Lumapower LM-301 is a good Cree Host

EngrPaul, now that I have my LM301 in my hands, more questions come to my mind. I'm struggling a little with the modification of the reflector "lip" you talk about; I made a drawing to illustrate my point.

The first drawing (I) shows how my unmodified light looks like. What I noticed is that the electrical contact c) is established by the battery tube treading against the pill d). If I untighten the head just a little the contact is lost, this is because my LM301 has anodized threads.

Now, in drawing (II) is shown what I imagine will happen if I start to remove material from the reflector lip f) which in turn will cause the pill h) to srew deeper into the head. As you can see the contact between the pill and the battery tube is quickly lost g) because the battery tube now treads against the head e) instead. Notice that this problem will occur quite soon due to the very little gap a). In fact, I can't see how I can remove any significant material at all without loosing contact.

My questions:
1. How did you avoid this problem?
2. By how much did you shorten the reflector?
3. What beam artifacts (too wide hot-spot, dark ring etc.) did you fix by shortening the reflector lip?

 

[EngrPaul]

Re: Lumapower LM-301 is a good Cree Host

paxxus,

nice drawings.

1. I did have that problem! To solve it, I applied solder to the printed circuit board, and dragged some over the eged of the brass pill (which takes solder) over top of the aluminum (which doesn't take solder, but will support the solder when compressed.) The solder bridges the gap.

2. I could only venture a guess as to how much I shortened it, .040"? Perhaps tomorrow I can bring home my calipers and compare a stock LM301 to the one I modified, and tell you the difference. Keep in mind, I used the Sandwich Shoppe Rev 2 board, which raises up the emitter higher than if you didn't.

3. I modded a bunch around the same time. If I can remember correctly, there was a dark spot in the center, and I just kept going until it was gone. I might get a tighter beam by removing more, I don't know. The beam is perfect and floody, I like it that way.

I'm having trouble logging into my photo server. When I get it sorted out I'll post some pictures of what I did for #1 above.

 

[paxxus]

Re: Lumapower LM-301 is a good Cree Host

EngrPaul,

Thanks

I understand now how you managed to get it working.

Yes, if you could manage it would be very helpful if you could measure the difference between an modified and un-modified reflector.

I'm building this light for an older person, so it has to be absolutely robust, so the mods I do must be very reliable.

 

[EngrPaul]

Re: Lumapower LM-301 is a good Cree Host

paxxus,

My picture account went bust! I created a new one.

Here is some helpful shots:

The hole needs opened so that it's slightly larger than the emitter:

You can see how much of the reflector lip I took off here with this next picture, along with my emitter. The orange Kapton tape I added because I thought something was shorting, until I figured out the body wasn't making contact with the ground connection. I left it on anyway. That's a Sandwich Shoppe rev 2 board under there.

Here you can see the solder I added to restore the connection that was lost because the pill goes in the head further:

After all was finished, here is how much gap I have (after twisting onto the solder pretty hard):

 

[EngrPaul]

Re: Lumapower LM-301 is a good Cree Host

Since my original pictures are gone here are some beamshots of a stock LM301 (Left) and a WH tint (greenish/yellow) P4 Cree (Right). Electronics unchanged.

Full Exposure:

-2 Stops:

I imagine I could have focused the beam a little more like the stock emitter was focused, but I liked it floody so I stopped short (assumably).

 

[Upplyst]

I followed your guide with good results.

It was pretty easy. I got the rev.2 cree board from sandwich shoppe. The reflow soldering went well. I also had the problem with the battery connection, but fixed it with some solder lumps on the brass ring. Furthermore I pulled out the spring a bit with a pair of pliers. There is one thing, though. I am not sure if I dare to sand down the reflector lips more. There is still a black star shaped hole visible in the center of the beam when i shine it 5 inches from a wall. Should I proceed and sand some more?

 

[EngrPaul]

Re: I followed your guide with good results.

It was pretty easy. I got the rev.2 cree board from sandwich shoppe. The reflow soldering went well. I also had the problem with the battery connection, but fixed it with some solder lumps on the brass ring. Furthermore I pulled out the spring a bit with a pair of pliers. There is one thing, though. I am not sure if I dare to sand down the reflector lips more. There is still a black star shaped hole visible in the center of the beam when i shine it 5 inches from a wall. Should I proceed and sand some more?

You should judge the beam at a few feet from a wall. 5 inches is rather close. You can stack the pill on top of the battery tube with a battery, and then move the reflector in and out to see how the focus is advancing. If it seems you are not quite getting close enough, remove more material.

 

[paxxus]

Thanks for all the pics and explanations! I've never done a mod before so I'm a little cautious. I'm still waiting to receive the Crees and I'll order the SS PCBs today. Any reason to use the more expensive CreePCB2, the original CreePCB is only $3. I can't really imagine the "Silver filled vias" in CreePCB2 to have any relevance at the low drive level of the LM301...?

Instead of sanding the reflector, I'm wondering if I could mount the Cree on some thin copper plate/spacer instead. That should still have adequate heat transfer at this relatively low drive level. Assuming that I use the SS PCB, the height of this copper (if I can get it somewhere) should be the same as what you shaved off your reflector.

Maybe you could measure the height of your modified reflector such that I can get an idea of the thickness of the needed copper spacer.

:thanks:

 

[EngrPaul]

Thanks for all the pics and explanations! I've never done a mod before so I'm a little cautious. I'm still waiting to receive the Crees and I'll order the SS PCBs today. Any reason to use the more expensive CreePCB2, the original CreePCB is only $3. I can't really imagine the "Silver filled vias" in CreePCB2 to have any relevance at the low drive level of the LM301...?

Instead of sanding the reflector, I'm wondering if I could mount the Cree on some thin copper plate/spacer instead. That should still have adequate heat transfer at this relatively low drive level. Assuming that I use the SS PCB, the height of this copper (if I can get it somewhere) should be the same as what you shaved off your reflector.

Maybe you could measure the height of your modified reflector such that I can get an idea of the thickness of the needed copper spacer.

:thanks:

I don't know anything about the old cree board. You are probably right about the relatively low drive of the LM301.

Raising the emitter should be a valid way to avoid shortening the lip. The SS sells .030" copper discs for the SSC-P4, you may want to get some of these (see the Seoul LED page). It may be a challenge to accomplish.

I'll get you those measurements tonight.

 

[paxxus]

:thanks: