Foothold Trap Modification: Night Latch Trigger

Foothold traps are my favorite kind of trap, and I use them almost exclusively with the exception of a few body grip traps. Foothold traps these days from all of the manufacturers are very usable out of the box, and do not require any modification. There are plenty of trappers who do nothing at all to their traps. That being said, I modify all of my traps. Some of the modifications make practical sense, others are just what I was taught to do and are things I like to see in my traps. There are a few reasons why one may want to modify their foothold traps:

1. To catch and hold the animal more effectively
2. To minimize suffering for the animal and any damage to the fur
3. To protect and preserve the traps

In this post I will discuss a modification designed to address the first point. A night latch is a foothold trap trigger modification designed to make the trigger more sensitive and to easily allow the setting of a hair trigger. I do it on all of my traps, and have been happy with the results. Similar effect can be achieved through several different means, but this is how I like to do it.

The goal of the modification is to make a secondary catch point on the pan for the dog to catch on that is closer to the edge of the pan trigger, thereby making the trigger easier to set off and requiring less pan travel. As an added benefit, you get an audible click when the dog engages the secondary catch. That is where the modification gets it’s name; the click allows you to set the trigger at night. Confused yet? It’s actually not hard at all. Let’s start with a diagram from the New Brunswick Trappers and Fur Harvesters Federation:

The above diagram shows the pan and dog mechanism of the trap. On top you have a standard trigger. On the bottom you have the night latch modification. Here is how I do it:

All you will need for the night latch modification is a metal file. I like to have a second small file as well for clean up work. You will also need a trap of course. Here you see a brand new Oneida Victor #1 trap. They are one of my favorite traps, and this one will be a replacement for one that previously went missing, once all of the modifications are completed. As a side note, if you are using traps like the MBs, which have a pan that does not allow any filing (you know it if you have such traps), you can do the same modification by filing a notch into the top of the dog instead.

Here is the trap set without any trigger modification. Specifically note the dog and pan.

The first step in doing the modification is to clean up the dog. Even on traps from high end manufacturers, the end of the dog tends to be sloppy, left the way it was stamped by the factory machines. It will work alright, but there are usually burs and uneven points that we don’t want. So, take your file, and make sure there is nothing protruding from any of the corners of the dog. I like to make sure that starting from the top edge of the dog, I file the rest back at a 30 degree angle. That way the top edge of the dog is smooth and is the furthest protruding point on the dog.

The next step it to modify the pan trigger. With a closed trap, and the pan sitting leveled, take the edge of the file and file out a notch on the bottom corner of the pan trigger.

Before:

After:

The size of the notch is a matter of personal preference. There is no practical need for the notch to be very deep vertically. All you need is enough of an indentation up so that you can feel when the dog catches is. Horizontally, the indentation has to be deep enough so that the trap does not accidentally trigger. If it is too deep however, the purpose of the modification will be defeated. I like to make the notches on my traps 1/16 inch by 1/16 inch. I find it gives me nice and crisp releases without any accidental triggers.

Here is the finished product, a set trap with a night latch trigger modification.

Now that you have the night latch set up complete, all that is left is to do some adjustments to make sure everything is leveled properly.

Depending on how the trap was set up prior to the modification, creating a night latch may alter the way the pan sits. In particular, if the pan was completely leveled when the trap was set prior to the modification, after the mod it may stand a bit higher when the trap is set. The goal is to have the pan be completely level when the trap is set. If it is either too high or too low, we need to make some adjustments to get it to be leveled.

The process for doing that is very simple. The dog is attached to the trap by an arm.

You can take a pair of pliers and bend that arm towards or away from the trap. You don’t have to do much. Very small movements in the arm will produce noticeable results on the pan.

By bending the arm in, towards the trap, the pan will be lower when the trap is set. Similarly, if you bend the arm away from the trap, the pan will be higher up when the trap is set. Like I said before, small movements in the arm will have noticeable effects on the pan. While there are special tools which allow you to do that, I’ve always been able to do it with just a pair of pliers as long as you don’t need to do any significant bends in the arm.

And that’s all there is to it. Like many other modifications, it is not necessary, but I think it makes for a better trap.