Just an update in case anyone else is thinking of trying this. I got the Blackjack BJ003 helmet mount and the TK20. I tried mounting the combo on my helmet and found a few problems.
First, the set screw on the Blackjack that secures the light in the mount presses on the rubber grip instead of on a metal part. I expected this, but just mentioning it for anyone else. In my opinion, this is a good feature, as it still secures the light in the mount, but it provides a shock-absorbing feature that helps protect the light. The modes can still be changed.
Second, the body of the light is a little long for mounting underneath the brim of the helmet unless you don't have a visor. I did manage to mount my Dereelight CL1H V4, but ran into the problems mentioned below. If I didn't have a visor, I believe it would have worked fine.
Third, with a visor, the Blackjack mount is unusable with pretty much any light. When mounted above the brim, the head of the light is 1/4 to 1/2 obscured by the visor mount and pivot regardless of the visor's position. The light still manages to throw a good beam, but it is dimmer. When mounted below the brim, it's good with the visor up, but with the visor down, the light shines inside the visor and pretty well kills your ability to see. The light also illuminates the brim of the helmet a little and some people may find the light distracting.
Last, the Blackjack mount has no adjustment for up/down at all. The beam from my TK20 in the Blackjack mount was ~18" up and to the left of my UK4AA at 10' distance. Being off to the left wasn't bad, but being higher meant I had to hold my head lower and roll my eyes up in order to see what was being illuminated by the hotspot in front of me. I could adjust the left/right with the Blackjack mount to some extent by installing it slightly skewed if I wanted to. It would have still been secure.
I didn't notice the additional weight at all. I mounted it to the left side of my helmet, planning to use it along with my current UK 4AA on the right side until it has proven itself. With both lights mounted, it was pretty balanced and, for the first time I didn't feel like my helmet was wanting to roll to the right. My plans now are to try again with the Helm-A-Clip mounts
H1024-1 and
H1024-3. I should have tried them to begin with since they allow up/down adjustment, they're cheaper and they appear very similar to
the mount we currently have, so they will most likely work. I got influenced by the Blackjack's reputation, which was apparently formed mostly by firefighters who either use goggles instead of a visor or who didn't have a helmet mounted light before and are using one for the first time and don't know any better. To be fair, it is a very well made mount and your light is far less likely to get hung up on something, but it is completely unusable in my application.
I'll post again when I try them out in case any other firefighters are looking for a flashlight helmet mount. I hope this information is helping someone. I will probably end up trying the Streamlight Vantage as well, but I expect to only use it as a backup light or scene light. The whiter light will work better for these purposes.
Tom
