koala
Flashlight Enthusiast
My adventures into the incan world didn't start very well.
I was feeling brave one day and flashed a MN21 with 3x LIFePO4.
I am glad to show you what I have done to resurrect a MN21, I hope you can try it too, with care of course.
What you need...
25-60 minutes
Dead M/K series lamp
Reference M/K series lamp, for the filament height adjustment
Soldering Iron
Pliers(to crush the glass lamp) + some sticky tape
Two 1" wire leads
1.25mm tungsten carbide drill bit
Dremel, motor of your choice
Your choice of bulb that will fit
To start, crush the SF glass bulb. Wrap the glass lamp in a few layer of sticky tape then crush it with the pliers. Hopefully the glass fragments will stick to the tape.
Now is the most time consuming and hardest part. If you have a carbide drill bit, use it, it takes only 20-30seconds. If you use the wrong tool, it will take a long time. Start by clearing the left over glass bits, becareful they are sharp. Then drill in to the ceramic, make a hole in the middle, but leave a layer of ceramic wall so it insulates from the aluminium shaft. Otherwise you will have to look for a heat/electrical insulator like what I am using.
If your bulb doesn't fit, shorten the aluminium shaft with a saw as needed. Leave at least 5mm of shaft height. I had mine cut and left 1cm of height.
Remove the existing leads from the springs, keep the springs, we'll be reusing it. We are trying to be green. Solder the two 1" wire leads to the bulb, insert the bulb into the aluminum shaft, use the reference bulb to find the right filament height. Solder one of the lead to the smaller spring. Check the filament height. Then solder the second lead to the bigger spring. Adjust and center filament as needed. Clean new bulb, to remove finger grease. Finish.
Enjoy your new lamp. Repeat from previous paragraph if you flash your bulb. It will probably take 5-10minutes this time.
Feels damn good to be green. It's such a waste to dump the original SF lamp assembly.
I was feeling brave one day and flashed a MN21 with 3x LIFePO4.
I am glad to show you what I have done to resurrect a MN21, I hope you can try it too, with care of course.
What you need...
25-60 minutes
Dead M/K series lamp
Reference M/K series lamp, for the filament height adjustment
Soldering Iron
Pliers(to crush the glass lamp) + some sticky tape
Two 1" wire leads
1.25mm tungsten carbide drill bit
Dremel, motor of your choice
Your choice of bulb that will fit
To start, crush the SF glass bulb. Wrap the glass lamp in a few layer of sticky tape then crush it with the pliers. Hopefully the glass fragments will stick to the tape.
Now is the most time consuming and hardest part. If you have a carbide drill bit, use it, it takes only 20-30seconds. If you use the wrong tool, it will take a long time. Start by clearing the left over glass bits, becareful they are sharp. Then drill in to the ceramic, make a hole in the middle, but leave a layer of ceramic wall so it insulates from the aluminium shaft. Otherwise you will have to look for a heat/electrical insulator like what I am using.
If your bulb doesn't fit, shorten the aluminium shaft with a saw as needed. Leave at least 5mm of shaft height. I had mine cut and left 1cm of height.
Remove the existing leads from the springs, keep the springs, we'll be reusing it. We are trying to be green. Solder the two 1" wire leads to the bulb, insert the bulb into the aluminum shaft, use the reference bulb to find the right filament height. Solder one of the lead to the smaller spring. Check the filament height. Then solder the second lead to the bigger spring. Adjust and center filament as needed. Clean new bulb, to remove finger grease. Finish.
Enjoy your new lamp. Repeat from previous paragraph if you flash your bulb. It will probably take 5-10minutes this time.
Feels damn good to be green. It's such a waste to dump the original SF lamp assembly.
Last edited:
petrev's mod's is a lot better, for the slot that centers the bulb.
