Addressing faulty Wurkkos DL70 diving light.
Wurkkos realised that a batch of their DL70 diving lights might have serious problems shedding the heat generated by the 4 XHP50.2 emitters. Cause of this was (IMHO) a combination of a manufacturing error and neglect in the QD. Or maybe just using a few wrong screws in the wrong place. Anyway, by the time they found out these lights were already on the road, and shipping them back and forth to/from the factory was going to be expensive. So Wurkkos offered these lights at a reduced price of $25 to those who were willing to solve the issue at their own risk.
Though a number of members already have described how they addressed the issue, I too will explain how I did it. Maybe someone can benefit from it.
- First of all, loossen the bezel ring. Not because the first thing you need is access from that side, but with a “whole” light there is more opportunity of finding a surface to hold on to. Wurkkos did NOT use any glue here. On the contrary, the threads were very well lubed. Nevertheless you need to apply quit a lot of force, because the O-ring is not only compressed in an axial direction, but also by the rotation of the bezel. So you have to overcome the friction of the whole O-ring. That feels almost as if the bezel was fastened by team Amber. The solution is using the rubberised garden gloves of the missus. Because no glue is used, the bezet does not pop loose. You only notice there is (slow) progress because the picture of the diver on the bezet is moving slow but steady from one “ornament” on the head to the next.
- Now you can move forward by removing the battery tube from the head. You will see the driver, but that one is definitily glued! Others have already mentioned to use a screw in one of the two holes in the driver and than pulling it. After some failed attempts it seemed wiser to use two screws, and to make something like a yoke, to divide the force needed. The holes in the driver are 13.0mm (heart to heart) apart, and the most suitable screws for the job had a diameter of just under 3.2mm (1/8” ?).
- Fasten the yoke with the screws. Put a screwdriver under the yoke, apply an appropriate amount of force, and out she pops.
- Unsolder the driver. There is hardly any room for that and you can’t just pull it out. First you must “untwist” the leads coming from the driver so the driver can be flipped and be reached from the other side. Now you can unsolder the leads. Then things get easy. Unscrew the bezel and take out the reflector. That can be done by loosening the screw in the shelf between the leads. Before removing that screw, use it to push the refector out of the front of the head.
- The time has come to do some serious cleaning. Make sure there is no debris left and the shelf and ledboard are flat. Both were flat, so I did not remove the ledboard. I just checked if the screws of the reflector were fastened enough. Now you can see what causes the problem. The heads of the screws don’t fit the cavities in the shelf.
With the modest means at my disposal I measured that the 4.2mm heads are about 31.1mm apart, while the cavities of 4.0mm have a pith of 30.9mm. Check this out for yourself. Putting the clean reflector unit back in the head reveals that the heads of the screws don’t fit the holes and that the whole thing feels rather wobbly, to say the least, There is no point in fixing the problem by adding extra heat paste.
- The quickest remedy is to widen the holes in the shelf. Some say using a drill bit of 4.5mm would be enough, but I hate to admit that that one was a bit dull. So I used a brandnew drill bit of 5.0mm and that did the trick. After that I deburred the holes (for the leads) in the shelf. Quick test: no more wobbly refector unit.
- What comes now is textbook material: apply heat paste on shelf and ledboard. Put the reflector back in the head and fasten it with the screw between the leads. Solder the leads back on the driver. Rotate the driver a few times to twist the leads, and then push the driver back in the way it came out. Make sure the two asymmetrical protrusions on the ledboard go in the respective grooves and the leads don’t creep under the driver board as you are pushing it in. You’ve noticed I did not mention any glue, I’m quite convinced the battery tube will prevent the driver board from wandering around. Final touch: screwing in the bezel. While softly whispering: gimme all you got, Kitt!
And then: lights on!. Everything seems to be okay, and the light is getting hot pretty fast. Which is a good thing.
EDIT: If you don’t have gloves with enough grip available, you can use strong double sided tape on bezel to increase grip.
