cheaper p7 build

[jasonsmaglites]

is there a way to build a p7 mag without a $20 heatsink. there is a reflector on dx that isnt made for mag but has a base for $7. is there any cheap base reflector combos for maglites, or at least a cheaper mount for the p7?

http://www.dealextreme.com/details.dx/sku.13803

 

[jasonsmaglites]

need glue, thermal paste advice

i found some stuff on dx but its not artic. tell me if this stuff will help me with my maglite 3d direct drive p7 build.

thermal glue for led to heatsink
http://www.dealextreme.com/details.dx/sku.4579

heatsinking paste for heatsink thermal transfer to flashlight
http://www.dealextreme.com/details.dx/sku.4593

thanks guys, this will be my first build

 

[DocD]

yes you can use that set up BUT here's the thing thers no contact the the main body of a D size mag so it will over heat :shakehead but if you turn down the brass heat sink part it will fit a C size mag fill the hole up with a Al slug or copper and re drill the hole then DD you could be in business and a lot of thermal grease and a J bin and there's a P7 heat sink set up with reflector :thumbsup:

 

[Norm]

Jason, I think by trying to cut costs your going to end up with a very unreliable light. The P7 runs pretty warm even with the best heat sinking, it's not the area I'd be looking to cut costs, a poor heatsink could end up costing you your P7.
Norm

 

[rayman]

I have the same opinion as Norm. Just wait a little time and buy a good heatsink. In my opinion the heatsink is the most important part of a P7 Maglite.

rayman

 

[LukeA]

Re: need glue, thermal paste advice

I have 4579 and it's good stuff. A very thin layer is more important than composition. Plus it's removeable later if you need to.

 

[LED Boatguy]

is there a way to build a p7 mag without a $20 heatsink. there is a reflector on dx that isnt made for mag but has a base for $7. is there any cheap base reflector combos for maglites, or at least a cheaper mount for the p7?

http://www.dealextreme.com/details.dx/sku.13803

I have a couple of those rascals, but I also have a lathe.

What MIGHT work is to TIGHTLY fold aluminum foil into a strip that wraps around the brass base and snugly fits into the Mag. The test is easy. Run the light without the head on it and keep your finger on the heatsink. If it doesn't burn you after a few minutes' running (and the Mag's barrel is heating up, you're good to go.

Those ~$20 heatsinks being sold here are some of the best money you can spend. Also, look into getting a warm white LED. You may have to go MC-E. I did, and I'll never go back to cool white LEDs for flashlights or area lighting again.

$.02

PS I don't know when I'll be at the lathe again, but I'll whip up some extra D-size adapters for those things.

 

[jasonsmaglites]

which p7 bin do i want

my two options are DSXPJ and DSWOI. i think i want the swo cause it would be whiter than the sxp which would have more blue in it. but they're very close so is j or i better
I 3.25-3.5 forward voltage
J 3.5-3.75 "

i'll be using 3 ni-mh d cells so i guess they'll be darn close to 3.6 volts under load so i really have no idea. would the lower vf be more efficent or brighter?

 

[jasonsmaglites]

i wish someone could make a cheaper heatsink or heatsink/reflector combo like this one for a maglite. even if it was lower powered. but then i guess id be spending money on a driver/circuit so might as well get a nice heatsink and dd it.

for my 2nd p7 build, do you guys have any drivers you recomend for it. it would be awesome to make it dimmable. i guess they work just by playing with the switch for a second instead of fully clicking it like normal.

 

[DocD]

Re: which p7 bin do i want

Hi jason IMO use a J bin as it's a lot less likely to turn blue, burn up and die, i like swo this is bight white and not to every one's taste, as the ever endding search for a LED that puts out light like a Incan, only use a I bin if you going to use a driver of some kind, Der Wichtel driver, you just can't going wrong with but in say that a lot of CPF'ers do use I bin's

 

[jasonsmaglites]

the i bin is the lower vf. is there any efficency difference? if i get the j bin can i push 4d cells on it to overdrive it?

 

[DocD]

hi jason,
leds can not be over on there forward voltage, if it say 3.5v to 3.75v then that's what it got to be, amps that you led uses say for a P7 is 2.8 amps at the forward voltage
J bin P7 DD
1: 3.5v might see 2.4amps under driven longer runtime not as hot
2: 3.75 might see 2.8amps on spec
3: 4.0v might see 3.2amps over driven shorter runtime led gets very hot
4: 4.25 might see 3.6amps turns blue over heats and dies

J bin P7 with a driver to regulate votage and amps
1: 3.5 v and 2.8 amps on spec if the driver is fixed , job done
2: using a driver that adjust to what ever you need like Der Wichtel one
just means you can turn it to the Fv of any P7
1:i bin 3.25 to 3.5 mean that all it can handle as more Fv, more amps it will over heats and burn up.

Now thats how i see it BUT i might be SO VERY VERY WRONG on this

A fixed Fv into a led and then change the amount of amp or milli amps being pump into it, now there's some thing CPF modder's have been doing for quite some time i think with cree's and ostars but more amps = heat

If using a i bin maybe change your battery from li-ion to a lifePo4 the voltage is better suited to a I bin P7.
i hope this help's you jason cheers DocD