Did I get a defective Nightcore D20?

Nice light but it has an annoying "POP" sound when engaging the piston drive to turn light on or off. My D10s do NOT do this. If that was the only issue I would suck it up and not complain, but I noticed the other night the light was flashing on my windowsill. It wasn't beacon or SOS, but it was like an intermittent connection. Lastly how does one remove the retaining ring so I can lube the piston if that's what's causing the popping sound? My Quark tool doesn't fit it and a small pointy screwdriver wasn't able to budge it open.

The piston definitely has a different feel to the D20 - not quite a click, but a more positive press, so I know what you mean by the "pop". It should wear in a bit with use, but the flickering sounds not right. Did you leave the head tightened ?

Lastly how does one remove the retaining ring

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https://www.candlepowerforums.com/threads/210904

This is my guess. Sometimes the o-ring will cause a vacuum within the body if there isn't sufficient lubrication applied to the o-ring. So when you activate the piston, this might force the air to go pop. Er, somewhat like a small fart. :green: And if the o-ring is dry, it might not pop right back into original position due to friction and might cause the contact ring to remain at half activation, hence your blinking.

To ensure it's not, just clean the piston and lightly lube the piston's o-ring. If the problem still ensues, check and see if the contact ring gets stuck when you depress it manually. If it does, try rotating it somewhat and try it with the light again. I wouldn't remove the contact ring unless I intend to mod it because if the problem isn't fixed, the warranty could be voided. :shrug: Contact the dealer about the problem then.

Not relevant but i just got a D20 to use for low levels but the thing just shoots past the lower levels in the blink of an eye, stopping it at around 10-20 lumens seems to be some sort of reaction skill test

Not impressed

And since when was a Lead alloy used in flashlight?

geoffg said:

And since when was a Lead alloy used in flashlight?

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I presume since somewhere near the start of flashlight history, given that most solders are a combination of lead and tin?

Not to mention, lead-free solder is more expensive and very annoying to work with in comparison...

Mine must be full of the stuff then.

The heaviest flashlight i own

geoffg said:

Mine must be full of the stuff then.

The heaviest flashlight i own

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The bezel, tailguard, clip and piston are stainless steel. That's mostly where you're feeling the heft. It's my heaviest 2xAA flashlights, but it's the most durable one too.

So how does one open the tail to remove the piston in this. The 2 dots are spaced further apart so my Quark tailboot kit KEY doesn't fit it, and the pointy screwdriver wasn't able to turn it. What other tool should I be trying to use to unscrew the retaining ring?

I was pissed that 2 new batteries are dead already in the light (due to it turning itself on and off like a phantom light) within 2 weeks or so or however long I have had it since 4/7's shipped it out. These were stupid cheap so here's hoping they weren't getting rid of returned models or something.

Although I haven't tried it myself, Selfbuilt gives a full disassemble with pictures in the review that I linked to above:

Unlike the 1AA version, the piston cannot be removed from the open end of the body tube (i.e. near the head) – if you want to access the piston, you need to remove the clip and unscrew the piston opening retaining ring (you'll need a pair of tweezers or snap-ring pliers). Not that there is any real reason to do so, unless you want to check the lube status of the piston o-ring.

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You need a 1.3mm hex tool to remove the clip screws. After the clip is removed, unscrew the stainless retaining ring around the piston button with tweezers or snap-ring pliers. The piston will then slide out the tail end. Clean the grease from the piston, o-ring and body tube, then re-lube the o-ring with a less viscous lube.

Thanks NutSAK. The tweezers worked to unscrew the retaining ring. I was going nuts trying to do it with the icepick type screwdriver but it definitely helped having the 2 prongs of the tweezers to bite down into the indents to unscrew it.

Well the lube was globbed around the oring but the piston was dry and not lubed. I just smoothed out the lube already on there and incorporated the excess on the piston. Nice and quiet now and no flickering.

One wonders why it didn't leave the factory as it is now. QC goes a long way and I expected Nitecore did a bit better with their QC.

BTW I did read threads about the popping piston click sound. Now it is much nicer but still not like my D10, but with the size of the piston it is understandable that it will be a bit different.

You're welcome. I wouldn't have nearly the respect for my Nitecores that I do if I hadn't maintained the lube on the piston. I actually removed all of the stock grease and replaced it with Nano Oil. It made a huge difference!

The D series lights are great, but they're excellent when you improve the tactile feel of the piston. Not only do they feel smoother, but they're much easier to operate.

I think I'll be ordering some of that Nano Oil and Krytox fairly soon. Been hearing good things about both.