help w/ 64458 build on 4D M*g w/ 5x AW IMR26500

After a good amount of research and question-asking here, I have decided to build a 64458 on a M@g 4D platform powered by 5 IMR26500 cells.

I've got the host and a length of 1" sched 40 PVC pipe to build a battery holder out of.

Now, I'm getting ready to order the rest of what I need.

Question 1: Can this thing be powered direct drive, or does it need soft start and/or regulation? If direct drive will work, is the KIU switch the way to go?

Question 2: This is a budget build. I know that the FM heads would help me get the most out of this light, but that will likely have to be a "Christmas of next year" upgrade. For now, what's a good reflector/lens to use in the stock head? (I think I want SMO or VLOP; I may frost the top half of the bulb.)

Question 3: I got what appears to be a "naked" host at Home Depot. When I do the spring mod, do I still need to sand down the bottom of the tailcap? Is it "clear anodized?"

Question 4: I'm a newbie; the only other "mod" I've done is overdriving a 6-cell Magnum Star bulb w/ 3 x CR123a (in both a plastic Eveready host and a M*g 2C). What else do I need to know? Is there anything I'm missing that I need to be aware of?

Thanks for your help!

-j

I got impatient. I ordered bulbs from bulbconnection.com. I ordered boro lenses from flashlightlens.com. I ordered kiu switch kits from kiu. i ordered reflectors from kaidomain. i still need to order batteries (i plan to order from aw), and i still need a charger. i hope i'm on the right track. i've never soldered before, but i have an iron. i hope it won't be too hard to figure out...

consider this a lame but desperate bump. i want my build to go well, but i feel like i'm flying blind. let me know if i'm headed for disaster anywhere... i'm going off what i've been able to discern in my free time by reading this forum...

at any rate, i'll post pics and my experience trying to build this thing here, in hopes that it'll at the very least help other newbies like me who realize what is possible and want to jump off the deep end like i've done....

thanks!

-j

ifpo238,
Have you seen LuxLuthor's Destructive Incan Bulb Tests?
Hot off the charger five IMR26500 (5*4.2V = 21V) and could a Osram 64458. So, you might want to first check that the total voltage is under 21V before powering up a Osram 64458.

Also, you might what to look at the Osram IRC 64440 not as bright only 4221 Lumens at 18V, but runs at 5 amps and can handle 21V.

I bought some 440s as well. My hope is that there'll be enough "voltage sag" or internal resistance or whatever to avoid the . If not, I can probably use the 440 bulb to bleed off some of the voltage and then switch to the 458... It'd kinda be a shame to have to do that, though. If it comes to that, I'll be seriously considering an AW switch upgrade. If it works ok, the next upgrade will likely be a new, throwy FM head...

I was kinda hoping someone here had built this light this way and could tell me for sure...

Thanks!

-j

Have you seen the JimmyM regulators? I know you said budget build. These are 40 bucks plus shipping. But it is a soft start and so much more. It has multi-levels, blinks when the batteries are low, senses high temperature and it is designed to work with the Kiu bulb tower you already have on order.

that's a deal! thanks!

-j

It's built, and I'm a proud 458 owner, now. I skipped the regulation/soft start, and just built it direct drive. (I had seen some posts from fivemega that indicated that could be done...) It works. I may add a regulator later after I start removing resistance. I haven't done much of any of that, yet. I just wired it up. I connected the kiu socket directly to the aluminum switch housing-topper without using the nuts to separate. Seemed to get closer to the bottom of the reflector that way. Doesn't really "focus" like a small mag bulb, but I think I was able to adjust it to the tightest possible hotspot for a little more throw. Loads of spill, and this thing is bright enough that it made me giggle more than once. Haven't tried starting fires, yet... Also, first time ever to solder! Funzies!

One thing I'll note that I hadn't seen in other posts - the spring on the bottom of the switch housing was not making contact with the top of the top 26500 battery. I had to stretch it down a little to make the thing light up.

Still, fun mod!

update: the light passes the firestarter test with flying colors. a couple of secs on a dark spot of some crumpled up newspaper, and there were flames. (the wifey asked me nicely not to burn our house down.) i was shocked at how quickly this thing could start a fire. definitely going to store with batteries removed.

i dig this light muchly. (my father-in-law does, too. i think he wanted me to give it to him...)

-j