M4 on Steroids....MK II

After seeing Hburner's work on MSaxatilus' Surefire M4, I thought I'd get some 18650 LG 2400MAH cells and give it a go. I found a 17.75-18.25mm expanding hand reamer on ebay which was used from the UK and managed to get it for about 10 pounds including shipping to Australia. I didnt have a tap wrench so a mate and I took at it with a spanner. That took a while and we thought it was taking way too long and too much effort, so we attached the hand reamer to a hand drill and set the speed setting to the lowest and the torque setting to the highest. We also had it set on the 'impact' setting. This worked moderately well, but we found that it tended to still lock. Then we noticed the WD40. Brilliant! We sprayed down the inside of the M4 and took at it with the the reamer and it was smooth as silk. After reaching the 18.25mm, the WD40 had created a mirror finish, far smoother than the original finish. Now I can use 18650 LG 2400mah cells. My mate and I are really happy with the job!

Here are some pics to wet your appetite...

:goodjob:

Please be carefull with those very powerfull and unprotected LiIons

Will

Dude, WOW!! AWESOME job!! Which bulb are you planning to run?

At the moment it has an MN16 LA in it, but Im going to order an MN21 HOLA LA for it

Rechargeable M6, I like....

Congrats! Awesome job. Hburner had a great idea, much thanks to him for putting forth such a great idea.

MSax

I wonder how long the HOLA MN21 will run on the 2 18650 cells?

What's the draw on an MN21? 4+ Amps?
If it is, then the light will last about 30mins or usually less due to heat.

protaeus

which lamp assy did have in it when we put it side by side to the ROP at the park?

I burned up a switch on one of these running an mn21.

I haven't run the M4 switch, as it might be of a larger gauge wire since it is designed to run the m4 hola. In the case of the U2 clickie, it took about 8mins then the sweet smell of melted plastic (and a bubbly sound) occurred

Both an old 6P push and a U2 clickie get way too hot. I recommend you run the light for a few minutes, pull the switch off and feel the spring. If it is hot, the plastic (if any) will be like to melt with extended runtime.

I was using the MN16 the other day which is the HOLA for the M3T. It appears to be whiter than the regular M4 lamps.

Luna, thanks for the warning, I'll keep that in mind if I decide to run the MN21. At the moment though, I recieved the M4 from JanCPF with a clickie switch which I believe to be a Z58. If it does start running hot, I will consider moding it with some higher guage wiring.

I doubt that I will ever run it at a full 30 minutes though, so I dont think overheating should be an issue. Anyway, as soon as I get the MN21 I'll run some tests and see how it goes.

It is a great light! I like the M4 body better than the M6 and this is a good way to get 500 lumens out of the M4!!!!!!

Yikes! I'd be scared to death to take a $300+ light and do that to it! I'm glad it worked out though. What kind of runtime do you get from the stock M6 lamp? Do you get more than 20 minutes from the M4 HOLA?

I have only used the MN21 in my setup and get a solid 20 minutes out of it before dimming sets in. As for the MN60 and 61 I have not used them, they would not work anyway with the 186500s.

Its not a particularly difficult or challenging process and the finish comes out beautifully. As HBurner said, you cannot use the MN60, 61 LA because they require 12 volts whereas two 18650 cells only produce 8.4 volts at maximum charge. Using the MN60/61 LA produces an extremely yellow beam.

Besides, the MN16 LA produces a much whiter beam even compared to the MN60/61.

Hburner, did you get any problems with the tailcap when running with the MN21 LA? I am currently using the clicky tailcap z58 i think....

Not at all. It worked flawlessley. Even with my C3/KT2/A19, it works great!

hburner said:

Not at all. It worked flawlessley. Even with my C3/KT2/A19, it works great!

Click to expand...

How long have you run it? I should have an SW02 for it soon but it definately melted it after 8mins of runtime. How hot is your spring?

Also is this a longer term problem, as I've been running the combination for a bit longer than you. Just things to think about.

Protaeus said:

Luna, thanks for the warning, I'll keep that in mind if I decide to run the MN21. At the moment though, I recieved the M4 from JanCPF with a clickie switch which I believe to be a Z58. If it does start running hot, I will consider moding it with some higher guage wiring.

Click to expand...

I thought that might work but the internal contacts of the clickie are very small too. We will see how the SW02 works out.

I have been using mine since late Dec. of '05, mostly with the Z58 clickie. But I do swithc around with Z48, Z41. I have had no problems with any of them. I have run it for up 22 min about 3 times just to see how the 18650s would hold up. It got hot but my C3 with 2 18500s and P91 gets hotter.

When boring the tube out, is it necessary to leave a lip for the negative electrode of the LA or can you just bore straight through ?