Benchmade Mini-Ambush, flawed materials. (pictures)

Joined
Mar 19, 2008
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161
I purchased the Benchmade Mini-Ambush on a whim. It ended up being my work EDC.

Its light weight and blade design made it perfect for an office EDC where a longer or wider blade would scare the sheeple (this tiny thing does, so I am sure something bigger would make them flip out). The blade shape is also very useful for utility work.
It did come with a very obtuse angle so I decided to change it. I perhaps made it too steep but suffice it to say that the knife can get very sharp even if the AUS 8 steel it comes with doesn't hold the edge for too long. The AUS8 used in this knife seems softer than other AUS8's I've used by other manufacturers.

The shorter-than-usual pocket clip, while not the easiest to put on, does make the knife less noticeable in your pocket as it is closer to a pen clip than a knife clip.

Most importantly, the propetary Benchmade lock (ROLLING LOCK® WITH INDRAFT®) made it a joy to use. It has a very smooth opening, a great lock up and releasing the lock is effortless and "safe". With some practice you can even flip the knife closed.

The detent was strong, and when the blade was deployed it would kick out quite significantly (almost like a half assisted opening). It would do the same thing when closing (in the opposite way of course), which is why flipping it closed was possible.

I thought it was a great lock and wondered why Benchmade didn't have more models with it. After months of carrying it, I found out.

After months of light use the knife's detent was no longer working as it should, it also wouldn't kick out as it used to, making deployment a lot harder than originally perceived. It's definitely not as smooth when it doesn't push itself out.
I made sure it wasn't grime in the knife and then decided to ask here, with no luck.

I couldn't figure out where the detent was to begin with so I didn't know how to attempt to fix it. After looking at the knife open and close I realized how it worked.

As seen below, the knife has a pin on one side of its base. When open, this pin doesn't do anything. However when the knife is being closed, the pin goes into a cutout that has been carved into the liner of the blade. This liner is supposed to act as a spring. The pin squeezes itself through the cutout until it gets to the closed spot when it retained quite well. The resistance of the liner on the pin is what causes both the positive detent as well as the kicking out/kicking in motions.



The problem

The design itself doesn't seem to be the problem. In my amateur opinion, I think it's the materials. The liner is simply not springy enough. It's too hard. After constant back and forth resistance and friction with the pin, it simply bent back, making the canal the pin has to squeeze through a lot larger. Therefore there was no resistance for the pin. Effectively eliminating any detent in the knife.

After realizing this, I, thinking the steel in the liner wouldn't be as hard, tried to flex it in the opposite direction to try to make the opening slimer again. I didn't use much force, but the thing immediately broke.



So now I have a knife with no detent, that is not too smooth to open. It is still usable, and since the lock is independent of this action it still works perfectly. Unfortunately, because Benchmade's warranty doesn't allow you to open your own knife I can't get a replacement.

Oh well, caveat emptor.
 
Send it back to BKC. They will take care of it. Considering the price of that knife, they will send you a new one. A small explanation will suffice. Even if you opened it up. As long as you didn't abuse it. They have the best customer service in the business.

BTW: Nice job on the review. I have one of these knives and understand it better now. Thanks.
 
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