Haikelite HK90 tear down

The HK90 is a rather unique light, triple SBT90.2's in a 100 mm diameter head, with triple 21700's in parallel. I recently got one in from Neal's store in sand color. This is about the closest thing to an old classic, the BTU Shocker, but updated. Of course I couldn't leave it in one piece for long, as I did with the Shocker with modding, so here's some of the details.

Had to give the 40T's a solder blob job for better contact:

Fortunately, they provided a large hole in the driver (on the left) that could be used for leverage to pry out the driver, breaking the glue seal. The glue is a soft silicone type of sealant, so not so hard to break:

These are the tools I used to pop out the driver. The bent end of the pry tool fit in the hole, then I used the plyers as a lever on the pry tool. Just had to add hard plastic on the edge of the head so not to damage it.

The driver is the same design as the HK04 - matches in every detail except the size:

Under the driver is where it gets weird. Normally with a reflector like this, there is one center large screw, but in this light, there is a screwed down aluminum plate:

Removing the plate, found this. Wut? It's a copper plug 1/2 filled with thermal grease, covering the screw head:

After cleaning it out:

So here's the pieces:

After polishing with a fine GRIT pad:

The Shocker reflector, ok, they modded it slightly to remove some weight, which is what I used to do on modding Shockers. They even made cutouts to clear the solder connections (I did that as well). They really still could have done more to reduce the weight, but maybe that would have been even more expense.

One large MCPCB, 20 AWG wires. Another weird thing - guess they ran out of black wire:

View of the shelf - light covering of thermal grease but well spread out (how it should be), and shelf is pretty thick, at least 4 mm:

Large MCPCB and 2.0 mm thick:

The copper plug is 35 mm wide by 9 mm thick. At the center base it's 3.1 mm thick and the outer wall is 5 mm thick:

The weight of some of these components:

The switch LED - these are dual color LED's, red and blue. The red and blue are controlled by the USB charging circuit, while Anduril controls only the blue LED's. This switch PCB is glued down, haven't tried removing it yet - I broke the HK40's switch PCB attempting to do so, so might leave as-is.

Couple of issue as well. The holes have not been deburred on the bottom of the MCPCB and there's a contaminant on the right side shown, might be solder:

Why are these wires so stiff? Turnigy and other wire we source from Hank-IOS or MtnE is much more flexible:

It is 20 AWG:

Here's a look into the driver cavity where the copper plug snugly fits in. It's a tight fit, but as you can see, there's no anodizing on the contact surfaces, they did the right thing here. The machining marks are almost cosmetic - I can't feel them at all. Looks like they polished the surfaces but didn't take it down enough to remove the marks - sanding should get rid of them easily. The aluminum shelf is 4.7 mm thick at it's minimum in the center, and 9.4 mm thick in the outer part. The LED's are probably 80% sitting over the thick 9.4 mm part. Since the thinner center section is supplemented by the copper plug, it's total thickness is about 7.8 mm at the center.

The center screw is an M5 x 16mm.

In the head, all the anodizing is stripped and the inside has ridges, dunno if intentional. Again, machining marks on the shelf but can't feel them, so the must not be significant. Sanding should smooth them out easily. If you notice, the anodized ring isn't exactly round, it has 4 flat spots which match up to the 4 flat spots on the MCPCB - interesting they made the fit tight and locks it in to position so no need for screws to prevent rotating.

Glamour shot of major components all cleaned up, showing relative sizes:

So I'm not quite sure what the purpose of the thermal grease is. There is no grease at all where the copper plug makes contact to the aluminum housing. Seems like applying a lot less to the outside of the plug instead of the inside would have had more thermal value? With the copper plug, I would think they were trying to keep the driver cooler and pull more heat from the LED's. Copper stores heat better than aluminum which can be a pro and con, but adding copper under the LED shelf is what many of us modders have been doing for years.

Overall, it's all what the Shocker was at the time - outstanding combination of lumens and throw with a big hot spot, and built like a tank, but with improvements:

  • SBT90.2 LED's - expensive but best combo of lumens and throw
  • side e-switch with driver running Anduril (wish it was firmware updateable from the outside though) with dual high performance Infineon FET's
  • 3 21700's, so can run the high performance 30T's and 40T's
  • SS bezel - nice look!

Initial Readings:

Configured temp calibration by setting the temp to approximate correct, and setting the highest max temperature. It stepped down at the 25 second mark, so took the lumens readings as follows. Using 40T's with solder blobs on top:

  • 15840 lumens at start, ~14400 at 25 secs, might have already started dropping (these are maukka calibrated #'s)
  • 712 kcd taken at 5 meters, after doing the 30 second test on the same cell charge

I really don’t understand… there is literally no thermal path between the copper sink and the body?? Am I seeing this right? A triple 90.2 light WITHOUT a shelf?? Like $3 zoomy style? Just a floating copper puck?

Ooops, no. There's a thick alum shelf, unibody, part of the one piece head. The copper MCPCB is 59.9 mm x 2.0 mm in size, sitting on a shelf, at least 2-3 mm thick (didn't measure). The 35.0 mm x 9.0 mm copper plug sits below the shelf. I'll add a couple more pics.

Wow. Ok. I was shocked by my initial (mis)understanding. Still a very odd design ‘feature’ with that grease cavity lol. Really don’t know what the thinking is there.

The shelf is anodized, btw?

Nope, it's bare - post #1 updated with a pic of the shelf. They did some things right, but the burrs on the holes and edges of the MCPCB is not good. Unfortunately I find this on many lights.

Yea, can't figure out what they were doing with the thermal grease. Maybe storing it for future use?

Thanks for the extra pics. Really clears things up.

Not having a good thermal path to the reflector seems like a missed opportunity. A proper thickness washer in the center could potentially help pull away more heat in the first minute of runtime.

How are the + traces routed?

The traces, + and -, on the MCPCB are a little strange - one wraps of each LED wraps around the LED. On the driver, it's a straight connect of wires to thru holes to the brass ring.

This light is a pass for me. Thanks for the breakdown.
Not the quality I seek.

This is why tear downs are so valuable - you don't really know what you are buying. It's a shame these tear downs seem to be a thing of the past, and they either don't exist or are difficult to find for more popular name brands, but I don't think a NiteCore, Imalent or AceBeam tear down would fair any better.

Overall, even though they have a strange usage of thermal paste, the copper heatsink plug is a good thing to see in there, plus the large thick copper MCPCB is better than 3 separate ones. I also can't find anything wrong with the reflector and AR treated glass.

I think Haikelite is another example where they don't advertise or list all the features the light has:

  • advantages of 6063 aluminum over the standard, cheaper 6061
  • large copper heat sink
  • double high performance FET's
  • switch LED's configurable by Anduril (not even in the included manual)
  • dual tripod mounts

Yikes! This light is almost $300 and has stuff like a hollow heatsink filled with thermal paste? Ugh.

Thanks for the teardown; agreed, they are very valuable, and decreasing in prevalence.

I only ever buy lights to use as hosts, so really appreciate a teardown of an interesting light.

As for this light, well, from those images, there are design and construction elements which seem poor:

  1. Why use a separate chunk of copper if you’ve already machined a shelf?
  2. Why then fill that copper with heaps of thermal paste? Was more copper too expensive? If so, see #1.
  3. Issues you mentioned with the copper chunk and (more worryingly) the MCPCB having proper thermal contact.
  4. That Alu plate serves no obvious purpose other than retaining the (itself useless) thermal goo pile.
  5. With a reflector that large and heavy, either machine it to be lighter, or use it’s thermal mass to delay overheating. If they’re throwing out thermal paste, put some there instead.

Overall, it appears to me that they either didn’t care enough about their design, weren’t capable of improving it, or (most likely) wanted to release a new light with the latest emitters in fashion at the moment, with little care or consideration.

I’m sure that this light would be moddable in interesting ways (as of course you and others did with the BTU), but for $350, over twice the BTU’s price, I’d expect better.
Though, given what I’ve seen and experienced with Haikelite in the past, I’m not at all surprised.

Just fyi, we are talking about $136 worth of LED's alone in this light, based on Hank's prices and $250-$260 is the average discount price of the HK90. It's unfair to compare the cost to a BTU Shocker.

Copper heatsinks, below the shelf, was and still is a common modding technique - I've done probably dozens of them this way. The use of the paste here is the odd thing, though I still think the copper heatsink helps more than hurts.

We are talking about some major bump up in specs. The HK90 is roughly 8 times the candela of a Shocker and 4-5 times the lumens, mainly because of the $136 in LED cost, combined with a high performance driver. For modding, it's a modder's dream: keep the stock LED's (best available), and keep the driver. Not much to do except usual tweaks like sanding the MCPCB/shelf contact surface, re-grease, maybe bump up the wires to 18 AWG, maybe bypasses on the springs.

In a likely futile attempt to explain the odd design here, what are the chances that the hk04 driver fits nicely on the copper puck?

Thank you for the teardown, much appreciated.
Even if I wasn’t interested with this flashlight at first, I might have be if the design had been top notch. I doesn’t think that it is bad but the triple SBT90.2’s MCPCB would have benefit to be a bit thicker with a thicker shelf instead of a copper patch inderneath that doesn’t touch the housing.

Thanks for the tear down mate!
Also cost if you buy a brand name light and tear it down and break it, You will be crying this light is also expensive but at least lights like the haikelite are a bit easier to take apart. Except for the glued in driver sigh.

Oh boy, I'm doing a real bad job if you think it doesn't touch the housing - of course it does! It's screwed down solid to the shelf with a large contact surface, just that there's no thermal grease between those 2 surfaces. If I were modding this light without that stock copper piece, I might have done the same thing in a mod, with added grease of course .

Thank goodness they added a big hole in the driver to make it easier to remove than a Sofirn SP36...

Goin back in time, drilling a hole in the stock driver is what we used to do, but fortunately Haikelite laid it out so there's no components on each side of the hole, so no damage using a pry tool.

Something like this could work out well, replacing the stock screw:

The screw is a direct connection between the copper plug and the reflector, and swapping from steel to copper should help. I'm not sure of the screw size, only guessing here, plus it's rather pricey.

Where do you get copper hex bolts? Parkrose Hardware?

Pic above has a link to an eBay listing.

Min qty here is 25K (ouch!): https://www.zenithind.com/copper-machine-screws-1730607.html

But at least someone makes them